USE CASE | Fnirsi 1014D for testing amplifiers
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- Опубликовано: 26 авг 2024
- Recently Richard from LER tested this scope concluding that it's perfectly usable. I must agree and I figured I'd demonstrate what things I use it for and what limitations bother me in it. Overall I fully recommend this scope to all beginners, especially since it's the only affordable scope that actually works.
Does this scope have AC DC coupling as in other scopes to block DC component ?
yes, it does
you have to explain first , floating ground, bridge configuration used into the amp output, thanks for a great effort !!
Many people seem to ask for floating ground and how not to break the scope, to which I always answer: just get a cheap scope and you'll get it, if you break it you break it, NBD.
I'll look into making part 2 video to this one based on the feedback.
Thank you so much!
Thanks for the video pal. Very informative.
Any time! Thank you for the comment
Bardzo pomocny materiał, pozdrowienia z Polski
dziekuje i pozdrawiam
The advantage this scope has is the easy adaptation of USB power block to make it fully floating. Now, the big and important issue in the audio world is Bode plots (Frequency measurements) using the built in generator. The FFT is very difficult to work out, no manual available, and a lot of "hidden" (non logic) setups for this to happen. Can you guide us through this?
Thank you. I will look into that but if you need reliable FFT you probably need a bit more expensive scope :)
One thing I didn't know as of making that video is that this scope has AC coupling, I mentioned that you can use capacitor to work around that limitation but turns out there is no such limitation :)
@@blackhorserepairs Yes, I discovered that, although the internal gen is very limited, you can record freq. sweep from external gen and use that provided you can sync it all together....
The Fnirsi 1014D does not have switchable DC/AC coupling on the input? Why? That's absolutely crazy. Even a cheap $30 scope has AC coupling.
I just checked the manual and it does have AC coupling. That would remove that 4V offset. You need to learn when to use that.
this device relies on the external power supply, that doesn't matter though, note that I'm using the scope for both measurements and signal generation, so all black leads are on the same ground, regardless if there is AC coupling or not. Normally I connect it to battery power when measuring the output of amplifiers.
Thank you for your comment.
btw, what would you recommend for a $30 scope?
@@blackhorserepairs If you enable the AC coupling, the DC offset has to disappear. Whether all leads have the same ground or not or whether the generator is internal or external. When you select AC coupling it just switches a capacitor in series between the probe input and the scope front end. Try it. My Siglent SDS2504X+ also has a built-in generator. So I know this will work.
I don't really recommend it, but I was thinking about the DSO-138.
@@uni-byte thank you so much, you're right, my coupling was set to DC (available in the probe config menu) I guess I have to make an addendum to this video :)
I have no idea how so many RUclipsrs gave this scope fantastic reviews (free toys) when it came out.
It’s so bad Fnirsi gave me a full refund when I complained and they didn’t even want the unit back.
@@MustangBoss1973 Interesting, what was your main complaint?
I find this information useful, thank you. How do I adjust the amplitude of the sinewave signal from the signal generator?
as far as I know that is not adjustable, if you want to drop it though just use 2 resistors
Or a pot
Sir is it still working fine?
yes sir, you can see it on my bench :)
Would this be adequate for a tube amp ?
of course, real output power calculation is not dependent on the type of output stage, it can be transistors, vacuum tubes, it can be class A, B or D, doesn't matter. You can also use it for repair of vacuum tube amp.
In fact, you can use much lower quality scope for that since the highest frequency you deal with on audio amps is around 20kHz, this scope can reliable measure 10MHz signals (I confirmed myself) and should be reliable up to 100MHz
@blackhorserepairs cool. Thanks. I have been building amps for a year but haven't gotten into using scopes yet. I need to track down some oscilations. I knew this wasn't a high end scope soni wondered.. and inheard it doesn't reliably measure up tk 100MHz but I don't really know what that would mean.
@@soapboxearth2 you are working within the audible range of frequencies, you don't really need the scope to confirm the oscillation in the amp. In fact you can use your phone to measure the frequency of oscillation just using the microphone. You can also connect probes to phone jack and use your phone as a scope. These frequencies are very low in the context of the rest of the spectrum.
This scope has the resolution of 1GS/s so you should be able to see the exact shape of your oscillation which might tell you where to look for the reason. This scope is a lot more than minimum you need for work on amps :)
@blackhorserepairs that's very interesting. I will look more into using a phone for that purpose..
I happen to have a 250 dollar credit for aliexpress. I mistakenly hit purchase on a number of items and couldn't get a refund, so I need to spend it on something. Sounds like this scope might be of some use.
@@soapboxearth2 well, I recommend it for the price it comes at, sure Rigol is better but for 3x the money and for most use cases Fnirsi is just as effective.
Good luck and let me know how you like it :)
I don't understand. You are saying the problem is that the probe is grounded to the chassis of the scope. Isn't that how all scopes are?
the point I was making is that the generator and the probe have the same reference point so connecting ground wire of the probe to the negative output of the amplifier basically shorts it to the ground. The negative output should not be shorted to ground so that's the problem. However what I didn't know then is that this scope supports AC coupling, I mentioned that I could connect the capacitor in series to go around this problem, and that's what's built in.
Hope this answers your question.
@@blackhorserepairs Honestly, I don't know much about scopes. I was looking for one to play with power supplies and maybe guitar effects. I don't understand fully why connecting the negative on an amp to ground causes problems or how AC coupling resolves it. If I understand you correctly, using a capacitor does the same thing. Does this have to do with capacitors not passing AC?
@@jpvoodoo5522 yes, the capacitor will block DC but let through AC, that's why it resolves the problem in this case. You can turn it on/off in the probe configuration menu (on this scope). On the output of the amplifier, you have a red and a black terminal. The black one is not ground, the current flows in both directions. So if your black probe sits on the ground the current will flow between the black output and the black probe. And if your scope is not insulated you blow the fuse, the scope or both.
It sounds a lot more complicated than it actually is, just start playing with it, experiment and you'll get it. That's the best way
@@blackhorserepairs, I am just beginning to play with electronics and I am hesitant to buy one of these 30-60$ ones because they have been trashed in reviews hard. I was looking at this one as an entry level or maybe the tablety version. I don't want to lay out a lot of money. But I don't want to be disappointed either. There are probably tons of tinkerers that feel this way. Would this be good for beginning projects like building a power supply, looking at USB data, watching guitar effect output, etc?
@@jpvoodoo5522 yes sir, for power supplies and audio this one is perfect, that's what I use it for mainly. For USB or SPI (especially analysis) this one is not the best choice, but it will get you started and familiar with scopes in general, and then you can search for something more precise and higher quality.
How do you get it to generate a signal?
the blue button at the bottom, click it and then use arrow buttons to change the signal shape and frequency
@@blackhorserepairs NOPE. You get it to generate a signal by plugging in the BNC lead one end to the signal generator (Green) back into one of the two channels (e.g. Blue). EVERY 'beginners' tutorial etc. has left this KEY point out. WHY?!??! It's like NOT telling people you need to turn ON the engine to a car to drive it. If you never seen a car before your not going to know are you??🤣🤣🤣
@@ojbeez5260 good point
Unfortunaly it isnt a video, how to use it for absolute beginners....
indeed it isn't but there are many great videos on using scope for beginners, I especially recommend Dave from EEVBlog.
thank you for the comment.
Nice toy for showing, not very suitable for work. Sensitivity 100mV, range 30Mhz, 200MSa. Pay extra and buy a Hantek - you can at least call it an oscilloscope.
you're absolutely right but (especially) lately I find myself not needing a scope so this one is still my only scope. I will definitely buy something more professional if I ever need it.
Do you have any particular model you can recommend?
Comment
The first one as always 😀
Tam gdzie elektronika muszi byc Polak
no pewnie ze tak :D
@@blackhorserepairs Wlasnie tez zakupilem ten oscyloskop do dokaldnie takich samych pomiarow no i kalibracji.
@@audiovideoes powodzenia
The FNIRSI 1014D is a heap of junk that does NOT come anywhere near it's claimed specs!!!!!!!!!!!
be it as it may, it is still better than not having a scope at all, junk can be handy sometimes 😁
@@blackhorserepairs Yep, not having a scope is like not having a left (maybe even right) arm in electronics. And in this case it was ultra low cost! :)
@@stevenbliss989 I worked with many scopes in my career but this one was the very first scope that I actually owned and when I got it I just kept staring at it for at least 10 minutes, this one is actually mine, sure it has its issues but it is a scope and it is all mine 😂
before this scope came out, I could not justify spending $800 on a device that I can live without, know what I mean?😉
What would be the best and cheapest scope that you could recommend?
@@blackhorserepairsMy first scope 30 years ago was Tektronix TDS320, great for it's time, but for most things my Tek 2465B etc was way better (I loved it)!
....BUT TODAY AS ASKED:
CHEAP bang for buck at US$200-230 odd: Hantek 2-channel DSO2C10 or DSO2D10 (built in low end arb signal generator). A step above what you have, but not too much.
BEST bang for buck at US$350: Rigol 4-channel DS1054Z (THEN software HACK to 100Mhz & all the decoders for free - easy to do!). A giant step above what you have.
If you can find a way, the Rigol with it's intensity graded & anti-aliased display, ...well worth the extra US$150. ...it''s like chalk & cheese!
For a good review of the Hantek: ruclips.net/video/Mmx7eo9STXE/видео.html
...and for the Rigol: ruclips.net/video/W2qdtQkBKhc/видео.html (teardowns etc. are on this channel as well)
I have both, and use the Rigol 100%, the Hantek is a backup in case bad things happen! Used to have a Uni-T and an earlier Hantek, but sold them off.
@@stevenbliss989 have many scopes.
I have 2 Flukes, onda Agilent, Rigol and various Owon.
Some days ago I bought the Owon SDS1102 for use with my curve tracer only.
After some testing I found this Owon working very well.
Owon cost is Us$180 only, is better in every posible way that the FNIRSI.