Few years ago when I lived in Italy, I picked up the 50eur Dab+ radio (mono speaker, built in power supply). I had to search for DAB signal outside my house, to get anything. Now I live in Poland and the signal is received in the kitchen, where it belongs!
Increase the dummy speaker resistor to 12 ohm and leave it always connected. That will reduce the load resistance to 3 ohm - theoretically - because the speaker has a weird reactance value range over the freq range anyway. Now you can use a simple on/off switch for each speaker. About the overkill output caps: you can easily use a standard electrolytic cap, as it will always have a DC value of 2.5V on the input, the way you connect it. Thanks for your efforts making this a valuable video with your ideas !
I'm a big Silercrest fan. I love the build quality and reliability. I would have used 4ohm resitors so you don't overdrive the output amps. Apart from that, a perfect mod.
Turns out that my attenuator resistors are too low for the capacitor value. About 1k would have been better. If I had used 4.7 Ohm dummy resistors, they would have had to be rated at 1W or more, so a bit chunky. Anyway I didn't have any to hand.
Those Frontier Silicon modules have always been much better than their price would suggest, decent quality DACs in them that wouldn't disgrace hifi components. And with there being so few supporting components it's difficult for the assembling factory to muck them up really. The little class-D ICs (PAM8403?) also really impress given they're literally pennies to buy.
Interestingly the Canadian government really promoted DAB in the 90s, and there was an experimental DAB multiplex in Canada that ran from 1999 to 2010 (I think). My main memory of the service was PSAs to try to convince people to buy DAB receivers. It was probably doomed to fail because DAB was never adopted in the US, and the electronics industry (and probably more importantly the auto industry) was not really willing to supply DAB receivers to the Canadian market but not the US market. Some of the commercial broadcasters here are using IBOC/HD-Radio now but unlike in the US there is virtually no marketing (or even on-air station idents) for it.
Good work ! I see (35:55) that the the chip manufacturer states that this also has a digital S/PDIF output. May be that by testing the pins with a "sounding" small piece of cable (DC decoupled) you can find one capable of turning on the latching LED of a small amazon's unexspensive D/A converter, 5V powered. The converter board could easily fit inside, which would solve the DC decoupling, volume pot independence and loudspeaker-bass-eq, if there were any.
Right look, it would be easier to source a proper audio transformer for each channel. That effectively takes care of the DC offset and the output level. As for switching the DPDT switch you discussed would work a treat.
4.7 µF and 360 ohms means f3 = 94 Hz - there goes your bass. You have multiple options to resolve this: 1. Ditch the attenuator altogether - they generally aren't worth it below 10-12 dB, and the 8002 in SE operation on 5 V can't output more than about 1.4 Vrms anyway, still less than CD player level. If you can just turn down the following amplifier without running into channel balance issues or the like, there is absolutely zero need for another attenuator. 2. Increase resistor values - about 1 kOhm each would still give acceptable output impedance. 3. Electrolytic caps would actually work fine in such an application, maybe some 100µ/16 V Panasonic FC or similar. I would go with (1). A pull-down resistor at the output would still be advisable, but it could be a 10k or something.
Thanks for your investigation. I found these devices in our german lidl-online shop for 23€. It's nice to see that these device has stereo. Most cheap units have only mono, that why I avoid DAB+ in the past. Very silly to see that there are sold out even with no reception at your location (without modification)..
Two more things that I'd like to add to this video: 1) try it with a linear power supply, not a switching one. Both my portble DAB+ receivers (a TechniSat Digitradio 210, and a pink Tesco one) perform much better on AA batteries than on any switch mode PSU (or the one included with the TechniSat). 2) the buttons will be most likely on a single pin of the Frontier Silicon module, just have a different resistor in series with them, and that's how the on-chip MCU knows which button has been pressed. With time the contacts will start acting up, and the buttons will be doing totally different things. I have this on my both of my DAB+ radios I mentioned above.
I could try another PSU, though as you will see in my follow-up video later in the week, I manage to get a pretty good signal from a small external aerial in the end. I've had that crazy button problem with some other low cost devices, it's quite possible it will apply here too.
Two audio iso transformers feeded from the circuit board the output of two transformers could connected as a common ground with a right and left outputs and the 2.5 volt dc level would not be a issue as it never makes to the speakers, A adjustable pot could used in series with a 82 ohm resistor as a limit for the line output control even would work if you for headphones without the resistors just a headphone jack to break the speakers free.
I''ll second transformers as the answer I'd just like to add, they make these as stereo pairs, with rca sockets on the output, for people who want to add a line level amplifier to a car radio which only has speaker outputs.
It looks like some of the UK DAB frequencies are used in the USA as one of the amateur radio bands, the 1.25 meter band (222-225 MHz). For digital broadcasting in the USA many stations use a hybrid analog/digital system in 88-108 MHz, but very few people own an HD tuner because the proprietary rollout was a total failure. Many wish to expand the FM band from 76-108 now that DTV is standard and TV no longer uses 76-88.
By the way, there are still using the low VHF band for DTV in the United States, especially now that UHF TV Channels 38-51 are no longer available because the FCC sold those frequencies to cell phone companies Iike T-Mobile for low range 5G service. As a result, the TV spectrum has now been truncated to low VHF channels 2-6, high VHF channels 7-13, and UHF channels 14-36. (By the way, Channel 37 has NEVER been used for broadcast TV in the United States.) As a result of the truncation of the TV spectrum, many stations formerly broadcasting on UHF channels 38 to 51 had to move to lower frequencies, which the Federal Communications Commission (FCC) calls a "repack". Due to this "repacking" of frequencies, there are still a number of full power and low power TV stations broadcasting on channels 5 & 6 (76 MHz to 88 MHz) like "6abc" WPVI in Philadelphia and the numerous Franken FM stations in various cities nationwide, which are technically low power TV stations using a digital TV signal along with an analog signal on 87.75 MHz broadcasting. These stations are known as 87.7 FM to the average listener and they broadcast essentially as radio stations on the left-most portion of the FM dial in the car. Until July 13, 2021, when the FCC shut down the last remaining low power analog stations in the United States and 12 years after all full-power analog broadcasting ceased in this country, they were low-power analog TV stations with an analog audio carrier broadcasting on 87.75 MHz.
The manufacturing cost estimate is based only on the component & packaging cost, and ignores the fact that the factory staff that assembled the components and packaged the unit also like to get paid for their work. There are also the factory and admin staff overheads, and cost of marketing & transport. It was stated that the R&D costs were ignored.
Thank you. Looking for a garden radio for mother, there is not much on Amazon that looks as easy to use as this and as cheap. I’ll hack a wooden box together, maybe some porting and see what those speakers are really capable of. Also, would be interesting to hack around with the module itself. Data sheets and application notes have a habit of surfacing in time!
IMO I don't know why all of those boxes including the radios and TV's come with an F connector when it's a cheap part to put in and everyone will be happy, even those that have to pull out an adapter they would have "something secure" to actually grip onto more than a piddly wire or RF port that comes out over time either through gravity or through the force of shifting furniture
Like how you managed to upgrade this - for me the most useful upgrade would be the ability to add an external aerial. Little wire type aerials never work very well, so I can imagine why your unit didn't pick up a signal with its piece of wire only. As for the TV aerial, chances are the Co-Ax itself is picking up the signal and not the TV aerial itself, as the TV aerial is cut to the wrong frequencies and also uses the wrong polarity (DAB is vertical polarity). Also, I'm not too happy about the state of digital radio in the UK either! Original flavor MP2 streams (the ones that are still left) are low bit rate and mono, and DAB+ AAC streams use an equally horrible bit rate, so whilst they are at least in stereo, DAB+ still doesn't sound good. And of course all of the DAB only radios can't receive most of the stations now! Lastly, I wouldn't want to advertise Heart FM as a feature of a DAB radio... Heart FM would probably be easier to receive on FM, and the station itself is not a good quality station anyway!
I agree, there are far too many channels with terrible bitrates in the UK. Little wonder that uptake of DAB has been so poor. Down here in Devon, reception is very patchy too.
If you want a more advanced project, look up your broadcasting frequencies, then look for a Yagi antenna design, most TV antennas are based on this design, then modify a TV antenna to the frequencies of the DAB+... Don't forget to point it in the correct direction.
Most of the TV antennas I've seen are log-antilog with some third design for the other frequency range, but a Yagi is easy enough that you can make it from lumber, screws, and copper plumbing, just so long as you have the dimensions.
You said at the start of the video, about the importance of having a stereo output, but many of the DAB & DAB+ stations only broadcast in mono anyway, some at quite a low bit rate too. You will often find that the better your audio system the worse these stations sound! Most of the stations now have an online stream as well, which is usually streamed at much higher audio quality than DAB. I was surprised at how few components & electronics this unit contains too.
I believe that the old DAB channels have been switched to mono because they sounded dreadful in stereo. The newer DAB+ channels are generally stereo. Yes I looked at the streaming option for my dad's place, but this DAB route was much cheaper and simpler.
I think its more about dropping the bitrate. Dab is all about loads of low audio quality streams. Lots of choice as a result which is great for a lot of people and its all free! If you wamt hi-fi stereo then the FM with a really great antenna is nice. Sometimes stations are only mono because there's only so much room on the national muxes. Dab+ can be pushed further but Dab+ radios are still rare. There is a little bit of stereo and joint stereo out there though....
That reminds me... Did you find you had actual stereo or joint stereo from the dab or was it only stereo on FM. I'm assuming it could really do stereo dab but I know I shouldn't just assume with this kind of thing
They tried to tell us that DAB+ at 32kbps would be equal sound quality to DAB at 128kbps. It's clearly not. I have quite a few older DAB radios that I've modified, but I just cannot listen to anything on DAB+, it reminds me if a poor quality children's toy. Given a more sensible bitrate, DAB+ would actually be a plus!
@@jobliss3932 On *some* , but not all DAB radios the display Will show the Letter 'J' to indicate if the station is transmitting in Joint stereo, from what I've heard Joint stereo is a sort of artificial stereo, where the signal is sent in mono, (to save bandwidth) along with a 'helper' signal, then split in the receiver to make it sound like stereo.
AM?! Wow. Can't remember when I last tried that probably about 40 years ago, I don't even know if modern radios are equipped with it. We get lots of free radio stations via satellite and the quality is better than DAB that way.
Judging by the block diagram you showed of the main chip it looks a lot like the DSP devices used in those Freeview USB dongles you can buy to plug into a PC, and can be used as software defined radio device that are capable of recieving from tens of MHz up to hundreds of Mhz, so maybe it isn't as expensive as you thought. Nevertheless its amazing what can be done with these kind of mixed signal devices. I must confess to being underwhelmed by DAB radio (although I've never tried a DAB+ one) because although if you're in a good signal area the sound was reasonable, as a substitute for a portable radio they weren't that good because they tended to eat batteries, especially compared to a standard AM/FM radio. I also found the fact that when signal was marginal the jarring sudden on and off of the audio was more objectionable than the distorted signal you got from conventional radio. However in the application this device is intended, where at least the signal strength is going to be stable and batteries are not a problem, then you've made an interesting mod to a quite cheap product (although Mrs Video99 seems less impressed!).
What I would have done is interrupted the volume controlled line level signals to the internal amplifiers, easier to mute the internal speakers that way - and avoiding all the noise introduced by the amplifier chips. The outputs should be typical "line" level with the volume up full.
You could possibly have used the signals at the *input* to the amplifiers to feed the line out (i.e. the audio out from the SOC). Those are presumably already single-ended and so may not need either attenuator or DC blocking cap. You could then cut the tracks of the Vcc supply to the amplifiers and feed Vcc to them via a SPST switch to mute the speakers. No easy way to avoid the volume control unless that is just providing a DC voltage to a VCA in the SOC in which case it could also be switched to hold it at a fixed voltage (on the same switch as the loudspeaker mute switch).
I don`t understand why do you not take the audio out from the inputs of 8002 ICs? Maybe through a small preamp? There the signal is referenced to ground and could use line out connectors with switch inside that interrupt the signal to the 8002 amplifier, maybe grounding its input.
Just more complexity to add amplifiers where there are already amplifiers in there. Strangely, the signal input is not referenced to ground, that's also sat on DC. Certainly a solution like that would have been beyond most people to implement, whereas my solution can be quite easily copied by other viewers with basic soldering skills.
you could also use tantalum capacitor ..those are not cheap but very good with that application ..you only need to make sure you over voltage your capacitor for double or triple of max voltage
Hi do you think there is a easy task to do a DAB/DAB+ Fm and internet radio combined, I have seen a lot ot ESP32 kits for internet radio only built nothing that combines internet and FM/DAB while chips that offers the combined functionality like the frontier tech that you find in expensive audio modulles like Ruark are not sold to end retailers, Any ideas?
I'm glad I kept an old Band III log periodic aerial, the local Mux has few stations, so will experiment with an external aerial. I think I would fit an aerial socket on the back rather than a flylead. I had a similar arrangement on the back of a PACE TV STB and that was the weakest point which failed.
DAB certainly hasn't been the success it was supposed to be. Early DAB quality was ghastly, and reception is patchy even now. Yes, Multiplexes was the word I was looking for of course. VAT was ignored because I just assumed post-VAT pricing. The £25 is the total purchase price including VAT. It's incredible really that they built this and made a profit.
Oh, hello Mrs video99. Busted! A bit like my Mrs when a delivery turns up while I'm at work.... Whaaaat? she says, not ANOTHER radio? Well I do work overseas and like to have treats to play with when I come home.
Why did you not just take a tap off from pin4 of the input to the audio amp ic? and an in line switch to disconnect the feed to the chips pin 4 (and thus speakers) when using the tap off. Then use the volume control to set the line out level (as the output from the dab module is probably line levels anyway, just scope to confirm).
Because I'm not sure the signal level and impedance would be correct at that point, I suspect it would not be. The output from the module is volume dependant, I showed that in the video.
The menu looks identical as in cheap Technisat DAB radio. Apparently, they all use the very same chip. So... does it matter which one you buy (except if some look really ugly)? The Technisat, being a portable radio, has telescopic antenna, though.
If you're planning to use it as-is, I would recommend the Silvercrest because of the good amplifiers and powerful speakers. But if you plan to modify it anyway, just select whichever is cheapest and has the best features for you.
From your review you mentioned that it wasn't hard/expensive for manufacturer to add external antenna connection or line out/headphones connector. But you missed that not all features of the product is about expenses, it is also about marketing. From marketing point of view both features you mentioned are locating you in another, more advanced, target group than this specific radio was targeted and so they definitely has something to propose you in twice or more higher price range)
How about the humming noise, very audible at low volume? The humming seems to be independent of the power supply, meaning it's caused by the power stage on the board itself. Any fix for it?
Not had that. You might have an earth loop problem, so I think I would start by connecting the phono outputs to something battery operated, or even directly to efficient headphones, with nothing else connected up. Don't even have an external aerial connected. If you still hear the hum, and you've eliminated the power supply, then it does imply it's a locally generated noise. Try turning off the display backlight in the menu in case the driver for that is the cause. Hope that gives you some ideas of where to start looking.
@@video99couk Thanks for your reply, but we're talking about the Silvercrest DAB radio. No phono outputs, and it's a model with power supply only (no batteries). No ground loop issue. No interference from the power supply either.
Are the batteries you get supplied with the radio unit rechargeable Li-Ion 18650 batteries or just plain (rechargeable?) AA/AAA alkaline batteries? And, if they are indeed 18650 batteries (or some other size of Li-Ion rechargeable battery, like 26500, 14700, etc.) what voltage and capacity (mAh) are they? Thanks for reading my comment, stranger ☺️
Another mod that might be worth trying but I'm not sure if it will work is some of those ferrite polos. Dab is easily affected by RF issues from things like phones charging and computers etc. Maybe those ferrite polos on the power lead might help block RF? If you try it let me know how you get on!
I want to find out about ther other digital radio standard, the unfortunately named DRM, but I can barely find a set. Apparently it's big in India. But when searching for DRM radio, I got plenty of DMR two way radios, a portable set for £200 and a household set for £400!! And loads of DAB sets for a tenth of that price. Seems the cheaper option is to get a HackRF and software for my laptop.
What about downloading new firmware which should be available now, need an output look for a TOSLINK Output and use a seperate DAC with a TOSLINK input connect the two together via a optical patch lead.
Downloading firmware? How? As far as I'm aware, TOSLINK (based on S/PDIF) passes only digital audio bitstream between DACs and is not used for web/network interconectivity. Yes, it could be used (if fitted) to interface an onboard DAC and either S/PDIF or TOSLINK RCA/optical interconnects to an outboard DAC receiver, but this chap just wanted to be able to plug into a standard traditional 'hi-fi' system. As for updating firmware, the board did have usb pads... Whether that was for the 5v+/- power rail or full data-stream interface is another matter, but my first hunch was it could be used for firmware updating.
It's also intended to be used as a bedside clock / radio, and a headphone socket could be useful for that. Bluetooth I think might have made this unit too expensive.
Did you select this purely because you want this style of under cabinet radio ? I switched to a Google home mini some years ago, sounds fine in the kitchen :) DAB wise, silvercrest, ultra entry level, so I'm not surprised that it's deaf ;) Amazon echo also excellent for radio, they both just use TuneIn radio. Aren't the amplifier chips in this little bridged output devices rather than push pull... Hence the DC component. All makes for an interesting video, thanks as always.
I chose it because it was small, neat and cheap! Whilst entry level, the radio module employed can also be used in more expensive devices so the performance is very good. That's what can be great about modern electronics, even cheap items can perform brilliantly because it's almost impossible to screw up the operation of a bought-in module or chip. Yes, the amplifiers are bridged (push-pull on both terminals), but the point is that neither terminal is at 0V and a DC block is required.
Very true indeed, frontier silicon make majority of modules these days I think. As you say amazing for £25 ! Some of the Majority radios are nice too. I bought my first DAB tuner back in about 1998, I took part in a field trial of dab back in 1994, had a technics ST-SG1000 at home for a while before it was released ...fun days :)
I live somewhere with good DAB reception and have a not very cheap Sony micro component reciever yet inside it is still problematic, have to be very particular about how the antenna is arranged. Even if you think you've got it right, if someone stands in a certain spot in the room it drops out! I didn't think that could happen with this type of antenna.
Gives you lots of audio streams when your internet is down though and doesn't saturate your bandwidth, especially when you have a family sharing one connection..
I think - based on what was being displayed - the SoC might be less than £5. As I've a Logik DAB+ radio that I paid £17 for from Currys. But what I know about these things you could write on a resistor and still have space.
Those 4.7 uF are too small as you are driving two low value resistors. Try a 100uF and + goes to chip. By the way, push pull is the wrong term for this type of output. It is known as bridge output. You have two push pull amplifiers 180 degrees out of phase to drive the speaker. As you say this will give you twice the voltage swing as a single push pull amplifier with ground as the other speaker terminal.
Just to add, the amplifier chip is actually two class D, and not push pull. Each amplifier 180 degrees out of phase. That is a bridge configuration. In this way, with only a low supply voltage you can get a decent power output. I have seen your follow up video by the way.
Because if you did that, you'd get nothing! On a bridge amplifier the outputs are equal and opposite, so at the midway between the two resistors the audio signals would cancel each other out completely and all you'd be left with is the DC mid-rail bias!
This may be an utterly stupid idea, could you use a momentary switch at the end of the headphone plug to disconnect speakers? Once the tip fully inserts it would press in the momentary switch and connect the two channels together.
You could, but you'd be better off getting a headphone jack with the relevant switch contacts (I'd go for a switch on ground for this sort of thing), and use the switch to control some relays.
I didn't realise DAB+ also use a shockingly low bit rate. I think watching this video has made up my mind not to bother buying a DAB+ player. I was hoping DAB+ would be an improvement but it seems the radio stations favour quantity of stations over quality. Ah well.
Hi, complete novice questions. Could you have fitted a wifi Bluetooth capability to send it to a sound bar etc? and was the Arial adaption grounded? don't worry I will be getting my son to do any adaptions he is doing an electrical engineering degree, couldn't do it with my plumbing tools anyway Cheer Mike R.
Yes the point of the aerial modification was to provide a proper grounded input so you can connect a dipole or similar. It would be possible to add BT audio out, but the cost and complexity would be such that it would make more sense to buy a suitable BT DAB radio.
In the UK DAB was implemented in a way that caused stations to compress their signals to the point they sound terrible so I don't know how you're getting really good sound??
Why not take the input signal to the amplifier ICs and use that as your line out. Ok it may need a little boost with a simple op-amp circuit but it would be better than the output side
I think I would have used an opamp to get the attenuation right and get the output impedance and DC level right. I have to admit though, I'd have to do some research to re-learn all I've forgotten about opamps.
That would be a good solution. I was prototyping an internet radio out of aliexpress modules. There's a codec chip used in it, a VLSI VS1053b that could directly drive headphones. The catch with that chip is that its outputs aren't referenced to ground, but rather to a separate "common" DC signal (called GBUF, I think). Which is great if you're only using it for headphones - no capacitors, no recharge time, or even for line out when device is battery powered or isolated. The sound is crystal clear. I then tried to adapt it to normal, ground reference line out (as per appnote and common sense, with decoupling caps and everything), but I ended up with a bunch of extra noise in my sound because apparently audio out from codec in my particular circuit is noisy due to poor regulation and power hungry ESP32 nearby that sags the power slightly every time it accesses WiFi, and possibly (but unlikely) also injecting RF noise in nearby traces. So noisy audio outputs from codec sounded clear while they were referenced to similarly noisy common output because noises on all outputs were identical and cancelled out; and they sounded noisy referenced to clear, low impedance ground. That would've been a good application for an opamp buffer output, so it could avoid the noise and remove DC, except I don't have a bipolar power supply in my device. I ended up attaching another DAC to I2S output of the codec (MAX98357, amazing tiny D-class 3W amp with I2S input to drive single speaker with mono audio - it doesn't care about power quality at all, it simply always sounds clear), and using DC-coupled headphone out for exactly that - headphones.
@@ZXRulezzz I wonder what Colin's radio has as chipset. Maybe it has an I2S bus that he could have used? The vs1053b is a nice chip, I own one on an Adafruit board and contributed a bit to the firmware (and I mean literally a bit: when you initialize it, you can set a bit in a register to enable or disable MP1 and MP2 encoding and I contributed a patch to turn that bit on so it can decode DCC audio 😄).
@@JacGoudsmit You mean DCC as in Digital Compact Cassette? Nice! Never had a chance to play with DCC, but I own a few DAT tapes and a recorder. I haven't released what I have done yet (it's an experimental spaghetti mess), but I made my own custom S/PDIF transceiver with FPGA that works with raw 32-bit words. I initially did it so I could put music with index marks on DAT automatically, since DAT disregards CD and MD track changes; and digital outputs on PCs these days don't support arbitrary U and C subchannels... And now I can also record any S/PDIF streams raw, for "forensics" and whatever other activities... :) Regarding DAB chipset, looks like it's SIENA FS2415 by Frontier Silicon. Looking at its webpage, it indeed looks like it has I2S out.
The DAB modules are mass-produced. If a "radio manufacturer" wants to build a radio, they tell the manufacturer of the module which functions are required. Then the manufacturer of the module gives the "radio manufacturer" a circuit diagram of how the switch and display and audio amplifier must be connected. This means that the entire electrical development comes from the manufacturer of the module. The "radio manufacturer" only commissioned circuit boards to be manufactured and assembled and had to provide the housing and loudspeaker and a power supply. And has to take care of the financing and sales. The module manufacturer will reap the greatest profit, however, because they sell the same module and circuit millions of times around the world.
What you say here is only sometimes correct. The schematic coming from the module manufacturer is only true for low-end radios such as this unit. I have worked with manufacturers and DAB module suppliers in the far east and in Europe for over 20 years. The capability of the manufacturers varies greatly. Also, depending on the manufacturer, software customisation may be by the module maker or the manufacturer or a third party specialist. The modules often have build variations as well to only offer some features for higher prices.
As an American Digital radio here was a joke. The new Digital Tv standard ATSC 3.0 in the USA is now being tested in certain cities. FCC please make a Digital Radio standard that is cross compatible with ATSC 3.0.
Hello, you could have saved yourself the work. Many of these standard DAB/FM receiver modules are for a wide range of radios, with and without line-out. You could have measured with oscilloscope at which unused pin the unregulated line-out comes out. You can then turn down volume and line-out still works. With kind regards.
I was a little confused by you wanting to tap on to the speaker drive, as power amps always have a low constant hiss, but a large divider ratio would push the hiss way down man :-D. The 150-300 ohm resistors on a headphone socket jump to mind, when driven from a power amp. You were also pointing to the beast chip outputs, lower level and no hiss. I'm no lover of digital radios, they just sound distorted to me.
If I had tapped from the radio module before the output amplifiers, I wouldn't have had enough signal level or low enough source impedance to properly drive the output sockets. DAB+ does sound heaps better than the old DAB, especially at the very low data rates we use in the UK. Still FM can be better though.
I was always curious if it is possible to extract the digital bitstream of one of these digital radios or the "HD" radios and save that data to a file that can be played and edited like a wav file.
The ETSI stream should be extractable (including audio in mp2 or aac), but without documentation and tools it will be tricky to actually do. If you want it, some of the rtl-sdr dab open-source reciever projects would be a better place to start hacking. It should be able to recieve evrything within the DAB MUX at the same time. Raspberry pi of a later version + a rtl-sdr stick may be the way if you want your own control.
@@erlendse I have an RTL-SDR and a phone. I can use it on my pc too but the stations are all over the place. What do I need to do to pick up and save the digital stream?
Would be nice if someone came up with a firmware hack. Some stations are blocked because of regional codes. I have the same issue with DVB-HD2 reception near Germany while being in Holland. There are ways to bypass that restriction and with a good antenna and amplifier, you get excellent HD reception.
You could take wires from the built in speakers, but if you only have one speaker to fit then occasionally it may not sound right because you would pick up only one of the two stereo channels.
You will need vertical dipole or small yagi for the DAB frequency fit it outside, your old tv aerial and amplifier will not cover that range.When I was in the UK 12 years I used to sell DAB radios with FM band as the coverage in practice is so poor and still is with poor bit rates and mono broadcasts still
external antenna makes such a difference if you can get it set up right. This radio is a great find I suspect because its not that expensive... its dab+ and its actually stereo. One f the reasons so many Dab broadcasts are in mono is that most people listening have little mono Dab radios with tiny speakers. Its rare for someone to try and push it for higher quality. No one expects too much of it in that way.. Its fun to see someone trying to get the best of it. Its good value for all those digital streams. How many channels are you pulling in there so far?
That's more or less what they have done. There are not many old DAB transmissions left, at least not where we live. So old DAB radios are now fairly useless.
The video was getting a bit long and the soldering was mainly to the PCB lands for the speaker terminals which are pretty easy to solder. I'm just doing the same to the silver/white radio today.
DAB…..I hate it. Less sound quality, less choice, hit and miss reception. That’s how progress looks like on the airwaves. Internet radio offers at least a huge choice, sound wise it is only so so but hey, most receivers like the one you got there do not offer great sound fidelity anyway. DAB was designed for mobile use but even then it is no match for FM.
DAB+ is a good improvement on the original DAB which is ghastly. I'm not finding DAB or DAB+ much use in the car, reception down here in the South West is too patchy.
EU mandates that every new car must be DAB+ compatible since December of 2020. DAB was I think only in use Germany and the UK, and most countries now are already for years trying to roll out DAB+ Cheap mobile unlimited data plans, in combination with something like car play, many just skip DAB altogether and use the phone/spotify to play music, with superior reception.
Norway introduced DAB many years ago. Then they switched to DAB+, leaving a lot of people with unusable radios. Incidentally, most FM stations are scrapped so you have to buy a DAB+ radio to get coverage.
The original DAB did exist in the Netherlands, but they basically hit the reset switch in 2013 and killed it off entirely, with DAB+ being launched as its successor. Lots of DAB equipment went obsolete in the wink of an eye, though, but at least it ensured DAB+ would have proper adoption by the radio stations!
the worst radio and expensive in relation to what it offers, DAB it didn't work for two months, when I now turn on DAB mode, radio it restarts and shuts down ... bad, very bad...
Obviously your unit has a fault, or perhaps a firmware update has got corrupted. That shouldn't happen. Not that I'm particularly impressed with DAB either, but it can be useful in some applications.
Flippin 'eck, that's a great -Techmoan cameo- coffee mug!
Few years ago when I lived in Italy, I picked up the 50eur Dab+ radio (mono speaker, built in power supply). I had to search for DAB signal outside my house, to get anything. Now I live in Poland and the signal is received in the kitchen, where it belongs!
Increase the dummy speaker resistor to 12 ohm and leave it always connected.
That will reduce the load resistance to 3 ohm - theoretically - because the speaker has a weird reactance value range over the freq range anyway.
Now you can use a simple on/off switch for each speaker.
About the overkill output caps: you can easily use a standard electrolytic cap, as it will always have a DC value of 2.5V on the input, the way you connect it.
Thanks for your efforts making this a valuable video with your ideas !
Electrolytics could be used, as you say they will be properly biased. But I had some silly big capacitors to hand.
The dual timers are for cooking! Very useful 👍
I didn't think of that! It's a kitchen radio after all.
I'm a big Silercrest fan. I love the build quality and reliability. I would have used 4ohm resitors so you don't overdrive the output amps. Apart from that, a perfect mod.
Turns out that my attenuator resistors are too low for the capacitor value. About 1k would have been better. If I had used 4.7 Ohm dummy resistors, they would have had to be rated at 1W or more, so a bit chunky. Anyway I didn't have any to hand.
Those Frontier Silicon modules have always been much better than their price would suggest, decent quality DACs in them that wouldn't disgrace hifi components. And with there being so few supporting components it's difficult for the assembling factory to muck them up really.
The little class-D ICs (PAM8403?) also really impress given they're literally pennies to buy.
Exactly my thoughts, it was bound to be pretty decent quality.
Interestingly the Canadian government really promoted DAB in the 90s, and there was an experimental DAB multiplex in Canada that ran from 1999 to 2010 (I think). My main memory of the service was PSAs to try to convince people to buy DAB receivers. It was probably doomed to fail because DAB was never adopted in the US, and the electronics industry (and probably more importantly the auto industry) was not really willing to supply DAB receivers to the Canadian market but not the US market.
Some of the commercial broadcasters here are using IBOC/HD-Radio now but unlike in the US there is virtually no marketing (or even on-air station idents) for it.
Good work ! I see (35:55) that the the chip manufacturer states that this also has a digital S/PDIF output. May be that by testing the pins with a "sounding" small piece of cable (DC decoupled) you can find one capable of turning on the latching LED of a small amazon's unexspensive D/A converter, 5V powered. The converter board could easily fit inside, which would solve the DC decoupling, volume pot independence and loudspeaker-bass-eq, if there were any.
I was wondering about the S/PDIF output, though it might be disabled in firmware.
Right look, it would be easier to source a proper audio transformer for each channel. That effectively takes care of the DC offset and the output level. As for switching the DPDT switch you discussed would work a treat.
He has an SPDT but a DPDT (or rather a 4PDT, since two channels) would be a nice way to do it.
4.7 µF and 360 ohms means f3 = 94 Hz - there goes your bass. You have multiple options to resolve this:
1. Ditch the attenuator altogether - they generally aren't worth it below 10-12 dB, and the 8002 in SE operation on 5 V can't output more than about 1.4 Vrms anyway, still less than CD player level. If you can just turn down the following amplifier without running into channel balance issues or the like, there is absolutely zero need for another attenuator.
2. Increase resistor values - about 1 kOhm each would still give acceptable output impedance.
3. Electrolytic caps would actually work fine in such an application, maybe some 100µ/16 V Panasonic FC or similar.
I would go with (1). A pull-down resistor at the output would still be advisable, but it could be a 10k or something.
Good point, I think I will tweak the resistors!
First visit to your channel, thoroughly enjoyed this vid, subbed.
Have no idea what you taking about but it sounded good 😂 only watched it because I got one for my kitchen and its quite good, happy days.
Well basically my modification let's it be used as part of a hi-fi system. Yes they are quite good.
Thanks for your investigation. I found these devices in our german lidl-online shop for 23€. It's nice to see that these device has stereo. Most cheap units have only mono, that why I avoid DAB+ in the past. Very silly to see that there are sold out even with no reception at your location (without modification)..
I'm doing a short follow-up video on this. I got an external antenna to work quite well in the end.
Two more things that I'd like to add to this video:
1) try it with a linear power supply, not a switching one. Both my portble DAB+ receivers (a TechniSat Digitradio 210, and a pink Tesco one) perform much better on AA batteries than on any switch mode PSU (or the one included with the TechniSat).
2) the buttons will be most likely on a single pin of the Frontier Silicon module, just have a different resistor in series with them, and that's how the on-chip MCU knows which button has been pressed. With time the contacts will start acting up, and the buttons will be doing totally different things. I have this on my both of my DAB+ radios I mentioned above.
I could try another PSU, though as you will see in my follow-up video later in the week, I manage to get a pretty good signal from a small external aerial in the end. I've had that crazy button problem with some other low cost devices, it's quite possible it will apply here too.
Two audio iso transformers feeded from the circuit board the output of two transformers could connected as a common ground with a right and left outputs and the 2.5 volt dc level would not be a issue as it never makes to the speakers, A adjustable pot could used in series with a 82 ohm resistor as a limit for the line output control even would work if you for headphones without the resistors just a headphone jack to break the speakers free.
I''ll second transformers as the answer I'd just like to add, they make these as stereo pairs, with rca sockets on the output, for people who want to add a line level amplifier to a car radio which only has speaker outputs.
It looks like some of the UK DAB frequencies are used in the USA as one of the amateur radio bands, the 1.25 meter band (222-225 MHz). For digital broadcasting in the USA many stations use a hybrid analog/digital system in 88-108 MHz, but very few people own an HD tuner because the proprietary rollout was a total failure. Many wish to expand the FM band from 76-108 now that DTV is standard and TV no longer uses 76-88.
By the way, there are still using the low VHF band for DTV in the United States, especially now that UHF TV Channels 38-51 are no longer available because the FCC sold those frequencies to cell phone companies Iike T-Mobile for low range 5G service. As a result, the TV spectrum has now been truncated to low VHF channels 2-6, high VHF channels 7-13, and UHF channels 14-36. (By the way, Channel 37 has NEVER been used for broadcast TV in the United States.) As a result of the truncation of the TV spectrum, many stations formerly broadcasting on UHF channels 38 to 51 had to move to lower frequencies, which the Federal Communications Commission (FCC) calls a "repack". Due to this "repacking" of frequencies, there are still a number of full power and low power TV stations broadcasting on channels 5 & 6 (76 MHz to 88 MHz) like "6abc" WPVI in Philadelphia and the numerous Franken FM stations in various cities nationwide, which are technically low power TV stations using a digital TV signal along with an analog signal on 87.75 MHz broadcasting. These stations are known as 87.7 FM to the average listener and they broadcast essentially as radio stations on the left-most portion of the FM dial in the car. Until July 13, 2021, when the FCC shut down the last remaining low power analog stations in the United States and 12 years after all full-power analog broadcasting ceased in this country, they were low-power analog TV stations with an analog audio carrier broadcasting on 87.75 MHz.
The manufacturing cost estimate is based only on the component & packaging cost, and ignores the fact that the factory staff that assembled the components and packaged the unit also like to get paid for their work. There are also the factory and admin staff overheads, and cost of marketing & transport. It was stated that the R&D costs were ignored.
Really enjoyed your video, thanks for sharing, take care.
Thank you. Looking for a garden radio for mother, there is not much on Amazon that looks as easy to use as this and as cheap.
I’ll hack a wooden box together, maybe some porting and see what those speakers are really capable of.
Also, would be interesting to hack around with the module itself. Data sheets and application notes have a habit of surfacing in time!
A hack I would like to try, if the notes appear, is to add S/PDIF output. The notes say it is available, but the firmware may not support it.
They look the same size speakers as what you get in the Bose waveform CD radio players, and they sound pretty good.
IMO I don't know why all of those boxes including the radios and TV's come with an F connector when it's a cheap part to put in and everyone will be happy, even those that have to pull out an adapter they would have "something secure" to actually grip onto more than a piddly wire or RF port that comes out over time either through gravity or through the force of shifting furniture
Modified my DAB radio years ago, I turned it into a bin liner
Early DAB radios were horrible. DAB+ though is at least tolerable.
Like how you managed to upgrade this - for me the most useful upgrade would be the ability to add an external aerial. Little wire type aerials never work very well, so I can imagine why your unit didn't pick up a signal with its piece of wire only.
As for the TV aerial, chances are the Co-Ax itself is picking up the signal and not the TV aerial itself, as the TV aerial is cut to the wrong frequencies and also uses the wrong polarity (DAB is vertical polarity).
Also, I'm not too happy about the state of digital radio in the UK either! Original flavor MP2 streams (the ones that are still left) are low bit rate and mono, and DAB+ AAC streams use an equally horrible bit rate, so whilst they are at least in stereo, DAB+ still doesn't sound good. And of course all of the DAB only radios can't receive most of the stations now!
Lastly, I wouldn't want to advertise Heart FM as a feature of a DAB radio... Heart FM would probably be easier to receive on FM, and the station itself is not a good quality station anyway!
I agree, there are far too many channels with terrible bitrates in the UK. Little wonder that uptake of DAB has been so poor. Down here in Devon, reception is very patchy too.
I saw that unit at Lidl which I thought was odd because there is no DAB radio broadcast in this area at all on the island where I live.
If you want a more advanced project, look up your broadcasting frequencies, then look for a Yagi antenna design, most TV antennas are based on this design, then modify a TV antenna to the frequencies of the DAB+...
Don't forget to point it in the correct direction.
Most of the TV antennas I've seen are log-antilog with some third design for the other frequency range, but a Yagi is easy enough that you can make it from lumber, screws, and copper plumbing, just so long as you have the dimensions.
Great video! The timers are probably for use as cooking timers
Yes, that's been noted. It also makes for a nice bedside clock radio and you could use a timer as a snooze function.
You said at the start of the video, about the importance of having a stereo output, but many of the DAB & DAB+ stations only broadcast in mono anyway, some at quite a low bit rate too. You will often find that the better your audio system the worse these stations sound!
Most of the stations now have an online stream as well, which is usually streamed at much higher audio quality than DAB.
I was surprised at how few components & electronics this unit contains too.
I believe that the old DAB channels have been switched to mono because they sounded dreadful in stereo. The newer DAB+ channels are generally stereo. Yes I looked at the streaming option for my dad's place, but this DAB route was much cheaper and simpler.
I think its more about dropping the bitrate. Dab is all about loads of low audio quality streams. Lots of choice as a result which is great for a lot of people and its all free! If you wamt hi-fi stereo then the FM with a really great antenna is nice. Sometimes stations are only mono because there's only so much room on the national muxes. Dab+ can be pushed further but Dab+ radios are still rare. There is a little bit of stereo and joint stereo out there though....
That reminds me... Did you find you had actual stereo or joint stereo from the dab or was it only stereo on FM. I'm assuming it could really do stereo dab but I know I shouldn't just assume with this kind of thing
They tried to tell us that DAB+ at 32kbps would be equal sound quality to DAB at 128kbps.
It's clearly not.
I have quite a few older DAB radios that I've modified, but I just cannot listen to anything on DAB+, it reminds me if a poor quality children's toy.
Given a more sensible bitrate, DAB+ would actually be a plus!
@@jobliss3932 On *some* , but not all DAB radios the display Will show the Letter 'J' to indicate if the station is transmitting in Joint stereo, from what I've heard Joint stereo is a sort of artificial stereo, where the signal is sent in mono, (to save bandwidth) along with a 'helper' signal, then split in the receiver to make it sound like stereo.
There is no DAB here in the states. AM and FM are still alive and well for the most part and we also have SiriusXM subscription satellite radio.
AM?! Wow. Can't remember when I last tried that probably about 40 years ago, I don't even know if modern radios are equipped with it. We get lots of free radio stations via satellite and the quality is better than DAB that way.
great vid idea always wanted to see you do a mega upgrade
Was listening to Loose Ends on BBC Radio 4 while watching the video. How freaky!
Really great job. Glad your channel got recommended. I wonder if you could maybe fix a Russisn FM tuner for me ? I'm sure it's just the psu
Sorry I can't take on repairs, I have a backlog of my own machines to work on.
Judging by the block diagram you showed of the main chip it looks a lot like the DSP devices used in those Freeview USB dongles you can buy to plug into a PC, and can be used as software defined radio device that are capable of recieving from tens of MHz up to hundreds of Mhz, so maybe it isn't as expensive as you thought. Nevertheless its amazing what can be done with these kind of mixed signal devices. I must confess to being underwhelmed by DAB radio (although I've never tried a DAB+ one) because although if you're in a good signal area the sound was reasonable, as a substitute for a portable radio they weren't that good because they tended to eat batteries, especially compared to a standard AM/FM radio. I also found the fact that when signal was marginal the jarring sudden on and off of the audio was more objectionable than the distorted signal you got from conventional radio. However in the application this device is intended, where at least the signal strength is going to be stable and batteries are not a problem, then you've made an interesting mod to a quite cheap product (although Mrs Video99 seems less impressed!).
DAB+ is a major improvement. Without it, I think DAB would have died.
Enormous case for such few components.
What I would have done is interrupted the volume controlled line level signals to the internal amplifiers, easier to mute the internal speakers that way - and avoiding all the noise introduced by the amplifier chips.
The outputs should be typical "line" level with the volume up full.
There is no signal available to do that. It's all inside the system on a chip.
You could possibly have used the signals at the *input* to the amplifiers to feed the line out (i.e. the audio out from the SOC). Those are presumably already single-ended and so may not need either attenuator or DC blocking cap. You could then cut the tracks of the Vcc supply to the amplifiers and feed Vcc to them via a SPST switch to mute the speakers. No easy way to avoid the volume control unless that is just providing a DC voltage to a VCA in the SOC in which case it could also be switched to hold it at a fixed voltage (on the same switch as the loudspeaker mute switch).
Nothing a thousand watt amp and 4 six foot speakers can’t fix……👍👍👍
Need a antenna what about a Longwire Antenna connected to the DAB tuner via an UNUN should give a perfect 75R match to the tuner input.
I wish DAB+ would comes to USA but DAB+ frequencies is our 1.25 (220 MHz) Ham Radio band there. We have HD Radio but not all areas here have it.
I don`t understand why do you not take the audio out from the inputs of 8002 ICs? Maybe through a small preamp? There the signal is referenced to ground and could use line out connectors with switch inside that interrupt the signal to the 8002 amplifier, maybe grounding its input.
Just more complexity to add amplifiers where there are already amplifiers in there. Strangely, the signal input is not referenced to ground, that's also sat on DC. Certainly a solution like that would have been beyond most people to implement, whereas my solution can be quite easily copied by other viewers with basic soldering skills.
you could also use tantalum capacitor ..those are not cheap but very good with that application ..you only need to make sure you over voltage your capacitor for double or triple of max voltage
Hi do you think there is a easy task to do a DAB/DAB+ Fm and internet radio combined, I have seen a lot ot ESP32 kits for internet radio only built nothing that combines internet and FM/DAB while chips that offers the combined functionality like the frontier tech that you find in expensive audio modulles like Ruark are not sold to end retailers, Any ideas?
I'm glad I kept an old Band III log periodic aerial, the local Mux has few stations, so will experiment with an external aerial. I think I would fit an aerial socket on the back rather than a flylead. I had a similar arrangement on the back of a PACE TV STB and that was the weakest point which failed.
That aerial could work really well! A proper socket would have been a tidier solution but the flying lead was so much easier to put together.
DAB is broadcast in MULTIPLEXES and the frequency is the center frequency, of 1536. Also isn't VAT included in that price? DAB = Dead And Buried.
DAB certainly hasn't been the success it was supposed to be. Early DAB quality was ghastly, and reception is patchy even now. Yes, Multiplexes was the word I was looking for of course. VAT was ignored because I just assumed post-VAT pricing. The £25 is the total purchase price including VAT. It's incredible really that they built this and made a profit.
Oh, hello Mrs video99. Busted! A bit like my Mrs when a delivery turns up while I'm at work.... Whaaaat? she says, not ANOTHER radio? Well I do work overseas and like to have treats to play with when I come home.
Why did you not just take a tap off from pin4 of the input to the audio amp ic? and an in line switch to disconnect the feed to the chips pin 4 (and thus speakers) when using the tap off. Then use the volume control to set the line out level (as the output from the dab module is probably line levels anyway, just scope to confirm).
Because I'm not sure the signal level and impedance would be correct at that point, I suspect it would not be. The output from the module is volume dependant, I showed that in the video.
Fascinating video.
Aldi do a better DAB/FM radio with line out and bluetooth, but where would fun be [if you don't have to take it apart].
I was in Aldi today looking to see if they had any such devices but alas nothing interesting.
The menu looks identical as in cheap Technisat DAB radio. Apparently, they all use the very same chip. So... does it matter which one you buy (except if some look really ugly)? The Technisat, being a portable radio, has telescopic antenna, though.
If you're planning to use it as-is, I would recommend the Silvercrest because of the good amplifiers and powerful speakers. But if you plan to modify it anyway, just select whichever is cheapest and has the best features for you.
From your review you mentioned that it wasn't hard/expensive for manufacturer to add external antenna connection or line out/headphones connector. But you missed that not all features of the product is about expenses, it is also about marketing. From marketing point of view both features you mentioned are locating you in another, more advanced, target group than this specific radio was targeted and so they definitely has something to propose you in twice or more higher price range)
Well yes, that's how I picked up a DAB tuner worth £50 for just £25!
How about the humming noise, very audible at low volume?
The humming seems to be independent of the power supply, meaning it's caused by the power stage on the board itself.
Any fix for it?
Not had that. You might have an earth loop problem, so I think I would start by connecting the phono outputs to something battery operated, or even directly to efficient headphones, with nothing else connected up. Don't even have an external aerial connected. If you still hear the hum, and you've eliminated the power supply, then it does imply it's a locally generated noise. Try turning off the display backlight in the menu in case the driver for that is the cause. Hope that gives you some ideas of where to start looking.
@@video99couk Thanks for your reply, but we're talking about the Silvercrest DAB radio. No phono outputs, and it's a model with power supply only (no batteries).
No ground loop issue. No interference from the power supply either.
Are the batteries you get supplied with the radio unit rechargeable Li-Ion 18650 batteries or just plain (rechargeable?) AA/AAA alkaline batteries? And, if they are indeed 18650 batteries (or some other size of Li-Ion rechargeable battery, like 26500, 14700, etc.) what voltage and capacity (mAh) are they? Thanks for reading my comment, stranger ☺️
Just regular AA batteries.
Another mod that might be worth trying but I'm not sure if it will work is some of those ferrite polos. Dab is easily affected by RF issues from things like phones charging and computers etc. Maybe those ferrite polos on the power lead might help block RF? If you try it let me know how you get on!
Decoration not included means that you don't get the shelf that you see it fastened to on the box art.
I want to find out about ther other digital radio standard, the unfortunately named DRM, but I can barely find a set.
Apparently it's big in India. But when searching for DRM radio, I got plenty of DMR two way radios, a portable set for £200 and a household set for £400!! And loads of DAB sets for a tenth of that price.
Seems the cheaper option is to get a HackRF and software for my laptop.
What about downloading new firmware which should be available now, need an output look for a TOSLINK Output and use a seperate DAC with a TOSLINK input connect the two together via a optical patch lead.
Downloading firmware? How?
As far as I'm aware, TOSLINK (based on S/PDIF) passes only digital audio bitstream between DACs and is not used for web/network interconectivity. Yes, it could be used (if fitted) to interface an onboard DAC and either S/PDIF or TOSLINK RCA/optical interconnects to an outboard DAC receiver, but this chap just wanted to be able to plug into a standard traditional 'hi-fi' system.
As for updating firmware, the board did have usb pads... Whether that was for the 5v+/- power rail or full data-stream interface is another matter, but my first hunch was it could be used for firmware updating.
In a kitchen you want bluetooth not a headphone socket because you want to be able to move around the room whilst you cook!
It's also intended to be used as a bedside clock / radio, and a headphone socket could be useful for that. Bluetooth I think might have made this unit too expensive.
DAB (dunno about DAB+) uses the same FM band, so the aerial and reciever back end will be shared.
Incorrect, DAB(+) uses VHF high around 200 MHz, while the FM band is around 100 MHz.
Did you select this purely because you want this style of under cabinet radio ? I switched to a Google home mini some years ago, sounds fine in the kitchen :) DAB wise, silvercrest, ultra entry level, so I'm not surprised that it's deaf ;) Amazon echo also excellent for radio, they both just use TuneIn radio. Aren't the amplifier chips in this little bridged output devices rather than push pull... Hence the DC component. All makes for an interesting video, thanks as always.
I chose it because it was small, neat and cheap! Whilst entry level, the radio module employed can also be used in more expensive devices so the performance is very good. That's what can be great about modern electronics, even cheap items can perform brilliantly because it's almost impossible to screw up the operation of a bought-in module or chip. Yes, the amplifiers are bridged (push-pull on both terminals), but the point is that neither terminal is at 0V and a DC block is required.
Very true indeed, frontier silicon make majority of modules these days I think. As you say amazing for £25 ! Some of the Majority radios are nice too. I bought my first DAB tuner back in about 1998, I took part in a field trial of dab back in 1994, had a technics ST-SG1000 at home for a while before it was released ...fun days :)
I live somewhere with good DAB reception and have a not very cheap Sony micro component reciever yet inside it is still problematic, have to be very particular about how the antenna is arranged. Even if you think you've got it right, if someone stands in a certain spot in the room it drops out! I didn't think that could happen with this type of antenna.
Gives you lots of audio streams when your internet is down though and doesn't saturate your bandwidth, especially when you have a family sharing one connection..
I think - based on what was being displayed - the SoC might be less than £5. As I've a Logik DAB+ radio that I paid £17 for from Currys. But what I know about these things you could write on a resistor and still have space.
Wow that was cheap. Can you see if it has the same module?
Those 4.7 uF are too small as you are driving two low value resistors. Try a 100uF and + goes to chip.
By the way, push pull is the wrong term for this type of output. It is known as bridge output.
You have two push pull amplifiers 180 degrees out of phase to drive the speaker. As you say this will give you twice the voltage swing as a single push pull amplifier with ground as the other speaker terminal.
Both of these points have been made further down. I'm doing a part 2 where I discuss the required R and C values to get proper frequency response.
Just to add, the amplifier chip is actually two class D, and not push pull. Each amplifier 180 degrees out of phase. That is a bridge configuration. In this way, with only a low supply voltage you can get a decent power output.
I have seen your follow up video by the way.
Why not put the 2 resistors directly across the push-pull amp outputs and a Cap to their mid point to remove DC
Because if you did that, you'd get nothing!
On a bridge amplifier the outputs are equal and opposite, so at the midway between the two resistors the audio signals would cancel each other out completely and all you'd be left with is the DC mid-rail bias!
And if you meant from one output to ground, he didn't want to upset the DC conditions at the amplifier output
@@simonparkinson1053 Doh! Never thought of that
This may be an utterly stupid idea, could you use a momentary switch at the end of the headphone plug to disconnect speakers? Once the tip fully inserts it would press in the momentary switch and connect the two channels together.
You could, but you'd be better off getting a headphone jack with the relevant switch contacts (I'd go for a switch on ground for this sort of thing), and use the switch to control some relays.
Interesting. Here in the States we don't have DAB modulation to the best of my knowledge.
You use Satellite radio in the US which is far superior than DAB which is an inferior
technology with poor reception particularly in hilly areas.
I didn't realise DAB+ also use a shockingly low bit rate. I think watching this video has made up my mind not to bother buying a DAB+ player. I was hoping DAB+ would be an improvement but it seems the radio stations favour quantity of stations over quality. Ah well.
Not all DAB+ channels are low bitrate. Some sound fairly good.
There would be no point adding a headphone socket to what is intended as a kitchen radio, presumably for use while cooking. Bluetooth would be better.
It's also intended to be used in table top mode and as a kind of clock radio. So a headphone socket would have made sense in that use case.
Hi, complete novice questions. Could you have fitted a wifi Bluetooth capability to send it to a sound bar etc? and was the Arial adaption grounded? don't worry I will be getting my son to do any adaptions he is doing an electrical engineering degree, couldn't do it with my plumbing tools anyway Cheer Mike R.
Yes the point of the aerial modification was to provide a proper grounded input so you can connect a dipole or similar. It would be possible to add BT audio out, but the cost and complexity would be such that it would make more sense to buy a suitable BT DAB radio.
In the UK DAB was implemented in a way that caused stations to compress their signals to the point they sound terrible so I don't know how you're getting really good sound??
If I would like hi fi quality sound I d take another thing. If I listen to radio I usually search for contents, and music after that
That's very true of DAB, but DAB+ is much better.
I've just bought one from Lidl and the sound is distorted at low volume which clears at higher volume.
Sounds like a defective amplifier. Ask for a replacement.
Why not take the input signal to the amplifier ICs and use that as your line out. Ok it may need a little boost with a simple op-amp circuit but it would be better than the output side
Would it really be better? If I'm going to have to amplify the signal, I may as well use the amplifiers that are already provided.
I think I would have used an opamp to get the attenuation right and get the output impedance and DC level right. I have to admit though, I'd have to do some research to re-learn all I've forgotten about opamps.
Op-amps were never my favourite subject. The solution does work really well, and I'm now going to do the same to the white/silver unit.
That would be a good solution.
I was prototyping an internet radio out of aliexpress modules. There's a codec chip used in it, a VLSI VS1053b that could directly drive headphones.
The catch with that chip is that its outputs aren't referenced to ground, but rather to a separate "common" DC signal (called GBUF, I think). Which is great if you're only using it for headphones - no capacitors, no recharge time, or even for line out when device is battery powered or isolated. The sound is crystal clear.
I then tried to adapt it to normal, ground reference line out (as per appnote and common sense, with decoupling caps and everything), but I ended up with a bunch of extra noise in my sound because apparently audio out from codec in my particular circuit is noisy due to poor regulation and power hungry ESP32 nearby that sags the power slightly every time it accesses WiFi, and possibly (but unlikely) also injecting RF noise in nearby traces.
So noisy audio outputs from codec sounded clear while they were referenced to similarly noisy common output because noises on all outputs were identical and cancelled out; and they sounded noisy referenced to clear, low impedance ground.
That would've been a good application for an opamp buffer output, so it could avoid the noise and remove DC, except I don't have a bipolar power supply in my device.
I ended up attaching another DAC to I2S output of the codec (MAX98357, amazing tiny D-class 3W amp with I2S input to drive single speaker with mono audio - it doesn't care about power quality at all, it simply always sounds clear), and using DC-coupled headphone out for exactly that - headphones.
@@ZXRulezzz I wonder what Colin's radio has as chipset. Maybe it has an I2S bus that he could have used? The vs1053b is a nice chip, I own one on an Adafruit board and contributed a bit to the firmware (and I mean literally a bit: when you initialize it, you can set a bit in a register to enable or disable MP1 and MP2 encoding and I contributed a patch to turn that bit on so it can decode DCC audio 😄).
@@JacGoudsmit You mean DCC as in Digital Compact Cassette? Nice!
Never had a chance to play with DCC, but I own a few DAT tapes and a recorder.
I haven't released what I have done yet (it's an experimental spaghetti mess), but I made my own custom S/PDIF transceiver with FPGA that works with raw 32-bit words.
I initially did it so I could put music with index marks on DAT automatically, since DAT disregards CD and MD track changes; and digital outputs on PCs these days don't support arbitrary U and C subchannels...
And now I can also record any S/PDIF streams raw, for "forensics" and whatever other activities... :)
Regarding DAB chipset, looks like it's SIENA FS2415 by Frontier Silicon. Looking at its webpage, it indeed looks like it has I2S out.
@@ZXRulezzz Yes, *that* DCC 😄.
The DAB modules are mass-produced.
If a "radio manufacturer" wants to build a radio, they tell the manufacturer of the module which functions are required. Then the manufacturer of the module gives the "radio manufacturer" a circuit diagram of how the switch and display and audio amplifier must be connected.
This means that the entire electrical development comes from the manufacturer of the module.
The "radio manufacturer" only commissioned circuit boards to be manufactured and assembled and had to provide the housing and loudspeaker and a power supply. And has to take care of the financing and sales.
The module manufacturer will reap the greatest profit, however, because they sell the same module and circuit millions of times around the world.
What you say here is only sometimes correct. The schematic coming from the module manufacturer is only true for low-end radios such as this unit. I have worked with manufacturers and DAB module suppliers in the far east and in Europe for over 20 years. The capability of the manufacturers varies greatly. Also, depending on the manufacturer, software customisation may be by the module maker or the manufacturer or a third party specialist. The modules often have build variations as well to only offer some features for higher prices.
They might not want to have a headphone hookup for a kitchen counter tuner.
But it's also for freestanding and bedside clock/radio use.
@@video99couk They hired that guy from Apple?
Enjoyed that thanks Ireland
As an American Digital radio here was a joke. The new Digital Tv standard ATSC 3.0 in the USA is now being tested in certain cities. FCC please make a Digital Radio standard that is cross compatible with ATSC 3.0.
Would not supprise me if the most expensive part to that radio is the case.
Hello, you could have saved yourself the work. Many of these standard DAB/FM receiver modules are for a wide range of radios, with and without line-out. You could have measured with oscilloscope at which unused pin the unregulated line-out comes out. You can then turn down volume and line-out still works. With kind regards.
I did that, but there's no line out feeds that I could find. Some interesting digital signals though!
Is it any good for waking up in the morning??
It does include an alarm clock facility so could certainly be used for that.
I was a little confused by you wanting to tap on to the speaker drive, as power amps always have a low constant hiss, but a large divider ratio would push the hiss way down man :-D.
The 150-300 ohm resistors on a headphone socket jump to mind, when driven from a power amp.
You were also pointing to the beast chip outputs, lower level and no hiss.
I'm no lover of digital radios, they just sound distorted to me.
If I had tapped from the radio module before the output amplifiers, I wouldn't have had enough signal level or low enough source impedance to properly drive the output sockets. DAB+ does sound heaps better than the old DAB, especially at the very low data rates we use in the UK. Still FM can be better though.
I was always curious if it is possible to extract the digital bitstream of one of these digital radios or the "HD" radios and save that data to a file that can be played and edited like a wav file.
The datasheet for the module says that S/PDIF is available, but there's no more information and it may be disabled in firmware.
The ETSI stream should be extractable (including audio in mp2 or aac), but without documentation and tools it will be tricky to actually do.
If you want it, some of the rtl-sdr dab open-source reciever projects would be a better place to start hacking. It should be able to recieve evrything within the DAB MUX at the same time.
Raspberry pi of a later version + a rtl-sdr stick may be the way if you want your own control.
@@erlendse I have an RTL-SDR and a phone. I can use it on my pc too but the stations are all over the place. What do I need to do to pick up and save the digital stream?
The timers are for kitchen use.
Would be nice if someone came up with a firmware hack. Some stations are blocked because of regional codes. I have the same issue with DVB-HD2 reception near Germany while being in Holland. There are ways to bypass that restriction and with a good antenna and amplifier, you get excellent HD reception.
News to me that there were region codes on DAB. Here in the UK we don't get neighbouring country transmissions in most locations.
Use a combi socket one made for stereo audio and a Mik ?
can I mount 2Watt speaker on radio ?
You could take wires from the built in speakers, but if you only have one speaker to fit then occasionally it may not sound right because you would pick up only one of the two stereo channels.
Why it has to be so big?
Bummer You did not show any of the doing. Plus the device plugged in working in your setup.
You do see it briefly connected at my Dad's place. The actual soldering is a bit boring and video was quite long.
You will need vertical dipole or small yagi for the DAB frequency fit it outside, your old tv aerial and amplifier will not cover that range.When
I was in the UK 12 years I used to sell DAB radios with FM band as the coverage in practice is so poor and still is with poor bit rates and mono
broadcasts still
I have an aerial on order! I believe it's the old DAB signals which have been switched to mono, not the DAB+ ones.
I hope so Uk should have waited and gone for DAB+ as it is somewhat better
external antenna makes such a difference if you can get it set up right. This radio is a great find I suspect because its not that expensive... its dab+ and its actually stereo. One f the reasons so many Dab broadcasts are in mono is that most people listening have little mono Dab radios with tiny speakers. Its rare for someone to try and push it for higher quality. No one expects too much of it in that way.. Its fun to see someone trying to get the best of it. Its good value for all those digital streams. How many channels are you pulling in there so far?
is there a SPDIF output connection?
The specs for the module say that it's available. I suspect though it's probably switched off in the firmware.
You say that DAB is no good but DAB+ is, I've had no problem with DAB radio sounds good to me...
Many DAB transmissions are now in mono, which might not matter for your application but for many use cases, that's wholly unsuitable.
The two timers are definately useful in a kitchen. I use timers frequently while cooking, and often need different timers for each part of the meal.
hey just letting you know you hav a new sub like what U do
The best thing the UK can do with DAB radio is to scrap it and replace it with DAB+.
That's more or less what they have done. There are not many old DAB transmissions left, at least not where we live. So old DAB radios are now fairly useless.
wont using ground as a common make the crosstalk between the channels
Honestly there should be no dc applied to the internal speakers either.
There isn't, because they sit with 2.5V on both terminals in the quiescent state.
Oh man, you cut out the soldering part.
The video was getting a bit long and the soldering was mainly to the PCB lands for the speaker terminals which are pretty easy to solder. I'm just doing the same to the silver/white radio today.
DAB…..I hate it. Less sound quality, less choice, hit and miss reception. That’s how progress looks like on the airwaves. Internet radio offers at least a huge choice, sound wise it is only so so but hey, most receivers like the one you got there do not offer great sound fidelity anyway. DAB was designed for mobile use but even then it is no match for FM.
DAB+ is a good improvement on the original DAB which is ghastly. I'm not finding DAB or DAB+ much use in the car, reception down here in the South West is too patchy.
EU mandates that every new car must be DAB+ compatible since December of 2020.
DAB was I think only in use Germany and the UK, and most countries now are already for years trying to roll out DAB+
Cheap mobile unlimited data plans, in combination with something like car play, many just skip DAB altogether and use the phone/spotify to play music, with superior reception.
Yes, I do the same myself. I have DAB+ in one of my cars but usually stream music from Spotify instead. DAB reception is too unreliable.
Norway introduced DAB many years ago. Then they switched to DAB+, leaving a lot of people with unusable radios. Incidentally, most FM stations are scrapped so you have to buy a DAB+ radio to get coverage.
The original DAB did exist in the Netherlands, but they basically hit the reset switch in 2013 and killed it off entirely, with DAB+ being launched as its successor. Lots of DAB equipment went obsolete in the wink of an eye, though, but at least it ensured DAB+ would have proper adoption by the radio stations!
The TV aerial won't be optimised for DAB, not unless it's a VHF band 3 type, As DAB uses the same channels as the old 405 line system.
I mentioned that it wasn't designed for DAB frequencies, but it was better than nothing.
Robots in disguise.
Let me tell you this the D.A.B reproduction of music is really bad we were sold a herring ...
DAB is horrendous. DAB+ though is a very useful improvement.
Personally, I would be more likely to purchase this radio if it boasted that it could NOT receive Heart.
There are presets so you can select your preferred channels and avoid any that annoy you!
the worst radio and expensive in relation to what it offers, DAB it didn't work for two months, when I now turn on DAB mode, radio it restarts and shuts down ... bad, very bad...
Obviously your unit has a fault, or perhaps a firmware update has got corrupted. That shouldn't happen. Not that I'm particularly impressed with DAB either, but it can be useful in some applications.
DAB is terrible. Might be OK for background music in your heavy plant machinery, but no good to listen too.
DAB is the worst thing that ever happened to radio.
Agreed, but DAB+ at least made some amends.