Excellent craftsmanship; the finished project actually looks like it belongs in the system, "another testament to your abilities". Well done Paul, you certainly are a natural born teacher that we all benefit from.
I bet that thing sounds as sweet as it looks. Akai discreet amplifiers are rare. Sansui were the masters of discrete amplifier technology. Always love to see vintage anything on the bench.
That is a real pro job. It looks factory made. If a tech will open the amp after a few years he would go "Look at that, I had no Idea AKAI used smd's and circuits like that for the lights"
I remember these. Hi quality monster stereo amp from the late 70s. Very well built 120 watts RMS per channel with ample heat sinking. These meters indicate the raw power output of this amp instead of the typical VU. It is amazing how much lighting LEDs have evolved in the last 10 years with high power LEDS for flashlights and other in home as industrial light applications replacing incandescent and even florescent lighting these days. Very delicate work to surface mount these components. You definitely need very steady hands for this kind of microscopic detail work vs drilling holes in G10 epoxy glass circuit boards which is very tedious work. Mr. Carlson, you are indeed the master of custom circuit board design and fabrication.
+SuperCarver2011 Thanks for the very kind words! You know, youtube just sent me the notification for this message today. They must be updating the system or something.
I love seeing audio equipment being restored... This particular job is truly amazing and like others have mentioned... The finished product looks like it was always there from the beginning.. That PCB only needed a date on it... just to confuse the next person who works on it LoL...
Great project! I can't wait to do this with my old Nikko 8085 receiver. The dead incandescents have been bugging me for a while. I appreciate the time you put into making these videos, I've learned a lot!
+Mr Carlson's Lab It looks awesome. does the chip use PWM ? Any chance if getting a schematic or parts list? You are in a tie for my 3 favorite channels.I was into electronics as a kid.Being disabled the last 12 years I have feeling kind if useless and watching your videos has rekindled my interest in electronics and Iv been able to repair a few things.I wanted to thank you for sharing your talent with the rest of the world, It has pulled me out of a deel depression and has enabled me to continue to contribute again in this world. Thank you again dor sharing.
I would have made the LED adjustment external & user-accessible because as soon as you tell the customer it can change, he'll want to change it. Likewise, if you used RGB LED's, he''ll want purple or teal, when you pre-selected green. To make it simple, just pick green and a single resistor to set the brightness to all LED's equally. I know that's not the super-engineered Carlson way tho, and that's why I enjoy your channel. Wow, an autographed PCB for meter LED's. I'm sure he's very happy with it.
That is awesome work. I'm enjoying watching your video's. I like how you find the trouble and then go beyond just repairing it to original, even designing an improved circuit for the device. Keep up the great work and video's.
Another great video. What a beautiful upgrade to a fantastic amp. I still have my "bought new" Akai AA-1150 receiver and although I seldom turn her on, she still sounds great. Well made equipment.
Another fantastic video! It's the small touches like the fading and pots to adjust the LED brightness to user preference that really make a nice difference; definitely above and beyond a standard LED mod. Not to mention the custom PCB board. :) I've done a whole lot of these kinds of LED mods for old gear from replacing a CCFL backlight with an LED one for my main scope to illuminating the cassette areas in tape decks haha. I usually just use a few mosfets for switching, nothing as fancy as your mod. :) I also use "gels" (pieces of transparent coloured plastic sheets) which are normally used to adjust the colour temperature of lighting on film sets, to adjust the colour temperature of whatever LEDs I'm working with, to closer match the device aesthetically. You lose some light transmission of course, but it works very well in helping get rare and unique colours. For instance, if you use a white LED and filter it through a light orange filter, you'll get the same warm glow of the original incandescent bulbs, if that is a feature that you wish to preserve for whatever reason. These gels can be easily purchased from local video equipment rental houses, or eBay of course.
hi i have been enjoying your videos, i love your approach, the way you use modern parts in older gear is an inspiration, too many hacks rip out and replace components for the sake of it, you have the right balance of rebuilding and improving only where its required. oh and thanks for the tip about cap polarity, that has helped me remove some annoying noise on a metal detector circuit i have been building.
You ever thought of doing a column for Nuts&Volts magazine.... or have you? I like the way you showed how to solder smd's and the CB layout is very professional.. Great video.
Re visiting this video two years later, still an amazing job 👍 It's a real pity that you didn't put a dummy load on it and pull out the oscilloscope for some performance measurements! Would have been great to see how the old girl was doing!!
Did sort of the same with a Toshiba RT8710S to light up the tuner scale and strongness indicator (there was no light at all). However I used some warm white LEDs (of christmas decoration) to mimick the light of real bulbs. Personally I love the warm colors, such as warm white, yellow and orange. I think I had chosen yellow or orange to apply onto this model. But hey, that is just a matter of taste. Nice mod.
Paul, ever considered doing a time lapse segment? It'd be pretty fun to watch you populate that board (24:00). If it isn't too logistically intrusive perhaps give it a shot on a future build. I think it'd go over pretty well. At any rate I really enjoyed watching you tack those resistors on. I was wondering what your method for soldering surface mount components was for some time now. Glad I finally stumbled onto this restomod.
that was a really great way to get rid of the incandescents in an amp.i have an older technics that is going to get the same treatment but in red and that purple that's almost uv in color on the volume slider.thanks for the application idea and layout. btw....great repair and build vids.best to be posted so far.great work and detailed explanations. =dok=
I will have to look into building this, and replacing the LED's I have in my desktop VU display. Maybe incorporating the driver circuit with this circuit too.
Mr Carlson's Lab That's what people say. I mainly started learning electronics to repair devices as a hobby. Some PCB's are good and some are bad. On bad ones, my Hakko 808, even on 1, will lift tracks while removing components. How do you make the good ones so that the tracks take more heat and stick better? What is it that the cheap PCB's lack?
Robert Calk Jr. Hi Robert. The Hakko 808 is a good machine, it's just a little cumbersome for fine work. Temperature and "dwell time" or ( the amount of time you have the tip contacting the board) are crucial when working on PC Boards. Most newer PC Boards have "plated through holes" which join one side to the other. These connection holes add a lot of strength to the pad that your de-soldering. Older single sided boards are much more fragile due the single side construction. When de-soldering a double sided board, one must exercise caution not to pull the plated through hole out with the component. If this happens, you must now solder both sides individually, so really, your using the components leg to make the connection from one side to the other.
Mr Carlson's Lab Thanks. I try to be careful, but some PCB's, especially on fake devices, are so cheap it's hard to not lift tracks. I'm not even going to fool with cheap PCB's anymore - just not worth the trouble. I love my Hakko 808 - it is such a time saver. I can't imagine not having it. It's funny: even though it's not very expensive, I would probably go more postal on a thief trying to steal my 808 than if he was stealing my Fluke. lol
That's an elegant panel lighting circuit. The other day durring the yearly "spring clean" (rusken) in my neighbor hood (Oslo, Norway), people can throw out stuff from their flats and leave them outside until a garbage/recycler truck comes (and then throw it on the truck). Someone had tossed a Tandberg Sølvsuper 11 (1973). I picked it up. It's not that rear in Norway, Anyway its not working and I'm gonna learn all it takes to get it working. I really like that your circuit ramps the lights up/down like that at power on/off (nostalgia I guess). I'm going to do something similar too. The voltages are different though on the incadecant. Three 5V bulbs in series and a bleed resistor connected to the 28Vac directly at the secondary side of the trafo. What would be the next touch to the circuit.. light fading in pace with the bass line ? :) Just kidding. I just remember the Sølvsuper back in the day did this when it was playing too loud.
I love these videos. No job to big or to small . you treat each project the same. Love your work ethic . Did you finish your Onan hook up to your home , would love to see how you attached the unit to your power box .I'm sure you did some modes on the installation :)
Mr Carlson's Lab Thank you. Hope you video the installation. I know it takes longer but I think it would be a valuable reference a lot of people are installing back up power solar or generator. Thank you either way
Could you do a Tech Tip Tuesday on how to generally replace incandescent bulbs in circuit with LEDs? There is a lot of good info in this video, but I'd like to understand from a more fundamental point the science behind the conversion.
You do very nice work!! I love coming home at night after the house is quiet and listening to jazz with my tea and a good book! I own macintosh and even now the clarity and detail sometimes still surprises me! Have you ever heard of Dunlap Clark dreadnought 1000 power amps? Made in Waltham Massachusetts and would like to have them restored to factory condition by you? Let me know?
Oh! What a great processional job! But I "stayed on my hung" a little bit because you forgot to show us the circuit diagram of your dimmer board. Is your diagram published somewhere?
+rimmersbryggeri That decision is made in the CAD program. For double sided boards, the back side isn't mirrored, the top side is. So it needs to remain a decision between board work.
Yeha your right because the content is mixed The graphics are not flipped while the text within them is sorry I got a little confused there mirrors are confusing some times. Or rather you generate the graphics relative to them needing to be mirrored to begin with and not relative to the side of the paper they are being printed on.
Gahh I wish this was a kit, I don't have the knowledge nor the equipment to accomplish this. I just picked up an Akai AM 2650 and the lights don't work at all. Seems kind of pointless to replace the existing lighting when it won't last long term. Great job by the way looks amazing!
AESOME! What would it take to alter it to the voltage needed for a Yamaha cr-2040 and maybe simply solder pads instead of LED's so that wires for the 7 replacement LED's wires can be attached?
Hi again Paul. Regarding the transistor pack in the circuit. I think you said in the video or comments that they are run in linear region ? Are they configured as constant current drivers? Perhaps as emitter followers to buffer a control voltage ? I'm planning to do this myself soon. I've fixed my Tandberg Radio. It had a production fault.
Great video, with lots of useful info! Do you know if LEDs were much more expensive until around the mid-to-late 80s? I ask because I've been replacing burned-out indicator bulbs with LEDs in a lot of vintage amps & receivers lately, and I've found that everything made before, say 1985, used LEDs very sparingly. For example, I just finished working on a Yamaha M50 amp which only used LEDs for its power meter. Every other light, including the power indicator and the 'protection' light (a thin, red, translucent strip of plastic which would've been perfect for a small LED) was an incandescent.
Shmeh Fleh LED's back in the 80's were not bright enough for many dials. The really bright ones were very expensive. Now they are cheaper than incandescent bulbs. Unfortunately today, many designers (engineers) design the surrounding circuit to max out the brightness, which is why you see so many failed LED's.
I've personally never run across a failed LED, but I've seen plenty of modern electronics with obnoxiously bright ones, particularly since blue became a popular color to use. On a related note, adding the ability to dim the LEDs on that amp was a really good idea. A few of my own LED conversions came out a little brighter than I wanted, but I'm too lazy to open them up & swap in a bigger resistor or whatever.
Mr. Carlson. Wow in one word. WOW! My retro heart beats like a drum after seeing your video. Is this board available for an Akai AM2800? It is similar to the AM2950. It only misses the volme knob lighting because it is an older amp. I cannot find bulbs, because of the high voltage, this would be a great solution. Chapeau!!!
At what point whould you consired this project overenginering ? Perhaps hot spare auto replacement leds ? And dont forget to put photoresistor to auto adjust brightnes, with A/D converter and arduino averaging 3 photoresistor inputs on time series multipole Butterworth filter with left to right and right to left brightness increasin option, and as safety faeture please consider voice syntesizer " maximum brightnes exceeded system disengages " that whould mix well with Kraftwerk "I am operator of my pocket calculator" you can take it and calculate voltage drop to leds same effect...
Mr. Carlson, do you believe that an LED used in scenarios like this is superior to an original bulb? I read people sometimes complain that an LED ruined the aesthetic of their amp *but* I imagine that may be because they used the wrong LED and/or poor positioning?
It's GORGEOUS!! btw In a store there an Akai AM-U02 and an Akai AM-U03 both working and both for the same price. I'ld like buy one of them but Idon't know which is better. As far as I know AM-U02 is less powewrful (26watts per channel) but has a wider Hz range (10Hz-40kHz). ModelAM-U03 is a bit more powerfull (37watts per channel) but it has just 20Hz-20kHz
Hi Vinnie. Knowing what power level they took those measurements at is very important. Usually amplifier bandwidth is not taken at full power unless listed. 40kHz is well above our hearing by double and some, but the added headroom in the amp will make it produce the highs nicer. The 10Hz bottom end may be the 3dB down point, but it doesn't mean the sine wave is pretty. 10Hz is getting close to DC, and that takes some big parts. There is a good chance at a given power level, both amps may perform very close (frequency wise)
Thanx a bunch bro! So in a few words which one would you purchase if in my shoes? price is the same. On a hand there's the U02 - less powerful but with wider Hz range - on theopther hand there is the U03 a bit more powerful but with just 20Hz-20kHz. I don't know, but I get the feeling the little U02 is better as sound quality. A wider frequency Hz range is equals to a better sound IMHO, more vintage, warmer and more dynamic tone, more harmonics. Here's two links with their specifications; put an eye and look at these please; AM-U02 www.hifiengine.com/manual_library/akai/am-u02.shtml AM-U03 www.hifiengine.com/manual_library/akai/am-u03.shtml
every genres. The point is frequency Vs. powerful. AM-U02 has less powerful (26watts per ch) but can go to 10Hz to 40kHz. AM-U03 is a bit more powerful (37watts per channel) but its own Hz range is worst; 20Hz to 20kHz
Hi Howard. Thanks for the comment! I could have, but the problem is... Usually these are mounted in a cabinet or on a shelf of some sort. So positioning of a sensor is critical, or there is possibility of oscillation. Problem 2 is.... A Hole would need to be drilled on the exterior of the amplifier to facilitate that photo sensor. So The most stable choice was to have 3 VR's to adjust the dials separately for the most even, consistent light.
True, but an external light sensor which could be well placed. I did something the same on a Technics system where the display at night was way too bright. It worked very well, the sensor was placed on top of the bookcase that the unit sat on. Keep up the great videos, many thanks.
Very nice job. why change the color of the lights. I admit it looks great, but I like restorations bringing a unit back to it's original glory. I really dislike Leds on Marantz. But as I said this really looks great, even in green.
Mr Carlson's Lab My Heathkit AR-1214 is still playing without any mods after 30+ years except I noticed the bulbs have all failed. This would be a worthy project and looking forward to the circuit build. Since it's never been turned off in the past 20 years, except during power outages, should I be concerned about filter caps?
hankus253 Hi. I sure would be concerned, especially those Temple capacitors. 60Hz is a lot easier on those capacitors than the frequencies of these new switch mode power supplies.... But they are still well past their due date.
Hi..Great Vid! ...I have a black Akai AM-2650 myself which sounds awesome connected to my restored Garrard zero 100 sc turntable. Only problem is power level meters and lights not functioning... I've ordered some new bulbs as I quite like the old skool incandescent warmth. Is there a fuse in the meter circuit somewhere? or will I need new meters...HAs anyone else had this problem and can give me some advice?
Paul, is there a chance to duplicate your design for my old Yamaha amp with bulbs, I really like that green Alien color you picked... Thank you for awesome inspiration from all of us.
It's a shame there was no shot of the board underside. Also I guess you could drill some holes in the lid and supply the customer with a trimmer for home adjustment of the brightness!
Question : what or how do you safely discharge caps? It might be simple 101 type of stuff for you but I was hoping to hear your thoughts about this. And do you have the same approach regarding discharging internal high voltage components in tube products?
Excellent craftsmanship; the finished project actually looks like it belongs in the system, "another testament to your abilities". Well done Paul, you certainly are a natural born teacher that we all benefit from.
+John Cunningham
Thanks for your kind words John!
Boy, do I love looking at those 547 O'scopes, those were some serious engineering.
I haven't a clue what you're talking about but I love what you did.
I bet that thing sounds as sweet as it looks. Akai discreet amplifiers are rare. Sansui were the masters of discrete amplifier technology. Always love to see vintage anything on the bench.
I love how professional your circuit boards come out, your repairs go well above and beyond.
That is a real pro job. It looks factory made. If a tech will open the amp after a few years he would go "Look at that, I had no Idea AKAI used smd's and circuits like that for the lights"
+sobolanul96
Thanks for the kind comment! I have more video's like this coming soon..... Working on one right now.
Your repair on this amp was a work of art and thanks for the acknowledgement.
Senior Frog No Problem, stop by the channel any time!
You've done a man's job sir. We can only hope that years from now, upon opening the amp, some lucky individual will be delighted.
What a beautiful Amp. The high end 70's vintage audio equipment was the best ever produced. Great vid
Thanks Jimmy.
The fade to on is a really nice touch, it gives the "warming up" look. Great mod! It makes me want to overhaul my old stereo amp.
Thanks for the comment Nick. Keep up the great slow motion video's!
I remember these. Hi quality monster stereo amp from the late 70s. Very well built 120 watts RMS per channel with ample heat sinking.
These meters indicate the raw power output of this amp instead of the typical VU.
It is amazing how much lighting LEDs have evolved in the last 10 years with high power LEDS for flashlights and other in home as industrial light applications replacing incandescent and even florescent lighting these days.
Very delicate work to surface mount these components. You definitely need very steady hands for this kind of microscopic detail work vs drilling holes in G10 epoxy glass circuit boards which is very tedious work.
Mr. Carlson, you are indeed the master of custom circuit board design and fabrication.
+SuperCarver2011
Thanks for the very kind words! You know, youtube just sent me the notification for this message today. They must be updating the system or something.
I always enjoy watching your own PCB's and the modifications you do to the units you work on.
Thanks Paul!
I love seeing audio equipment being restored... This particular job is truly amazing and like others have mentioned... The finished product looks like it was always there from the beginning.. That PCB only needed a date on it... just to confuse the next person who works on it LoL...
Great project! I can't wait to do this with my old Nikko 8085 receiver. The dead incandescents have been bugging me for a while. I appreciate the time you put into making these videos, I've learned a lot!
+KingNast
Glad your enjoying the video's. Thanks for the kind words as well!
+Mr Carlson's Lab It looks awesome. does the chip use PWM ? Any chance if getting a schematic or parts list? You are in a tie for my 3 favorite channels.I was into electronics as a kid.Being disabled the last 12 years I have feeling kind if useless and watching your videos has rekindled my interest in electronics and Iv been able to repair a few things.I wanted to thank you for sharing your talent with the rest of the world, It has pulled me out of a deel depression and has enabled me to continue to contribute again in this world. Thank you again dor sharing.
I would have made the LED adjustment external & user-accessible because as soon as you tell the customer it can change, he'll want to change it. Likewise, if you used RGB LED's, he''ll want purple or teal, when you pre-selected green. To make it simple, just pick green and a single resistor to set the brightness to all LED's equally. I know that's not the super-engineered Carlson way tho, and that's why I enjoy your channel. Wow, an autographed PCB for meter LED's. I'm sure he's very happy with it.
That is awesome work. I'm enjoying watching your video's. I like how you find the trouble and then go beyond just repairing it to original, even designing an improved circuit for the device. Keep up the great work and video's.
Mr Carlson's Nice work, the green color is really nice and at the same time it works soothing!
Another great video. What a beautiful upgrade to a fantastic amp. I still have my "bought new" Akai AA-1150 receiver and although I seldom turn her on, she still sounds great. Well made equipment.
Such a professional job.
CofeeAuLait Thanks!
That certainly put life into a 30+ year old amp. Great job there.
Execelent work on the Akai amp it really looks much better now
Your circuit board designs are excellent so neat and tidy, love watching your videos lots and lot to learn in each and every video
A beautiful job, not the simplest way but something you can take pride in.
+g0fvt Thanks for the kind words!
Paul , That's a very professional looking job , Great looking Amplifier , The LED lighting really adds to the character of this classic amp ... 👌👌👌
Akai, I remember when they were big. I remember using their reel to reel machines
Beautiful! I love your attention to detail..
Fantastic! Love your channel, thanks for your amazing work and generosity of information in the field.
Glad you enjoyed!
Well Paul, another superior job. You are one fantastic tech, always with excellent craftsmanship.
Thanks!
Soldering is spot on! Keep up them IPC standards! Also, some conformal coating would probably be a good idea if kept out of the dims...
Another fantastic video! It's the small touches like the fading and pots to adjust the LED brightness to user preference that really make a nice difference; definitely above and beyond a standard LED mod. Not to mention the custom PCB board. :) I've done a whole lot of these kinds of LED mods for old gear from replacing a CCFL backlight with an LED one for my main scope to illuminating the cassette areas in tape decks haha. I usually just use a few mosfets for switching, nothing as fancy as your mod. :) I also use "gels" (pieces of transparent coloured plastic sheets) which are normally used to adjust the colour temperature of lighting on film sets, to adjust the colour temperature of whatever LEDs I'm working with, to closer match the device aesthetically. You lose some light transmission of course, but it works very well in helping get rare and unique colours. For instance, if you use a white LED and filter it through a light orange filter, you'll get the same warm glow of the original incandescent bulbs, if that is a feature that you wish to preserve for whatever reason. These gels can be easily purchased from local video equipment rental houses, or eBay of course.
Hi whatlions, thanks for the comment!
I so enjoy your videos, so informative. And your outcome is the best I have seen. Thanks so much for the info and the entertainment, a joy to watch.
Senior Frog Thanks for the nice comment!
thank for your well and profound explanation and demonstration, very educational and i learned a lot.
hi i have been enjoying your videos, i love your approach, the way you use modern parts in older gear is an inspiration, too many hacks rip out and replace components for the sake of it, you have the right balance of rebuilding and improving only where its required. oh and thanks for the tip about cap polarity, that has helped me remove some annoying noise on a metal detector circuit i have been building.
aly nicholls Glad to hear your enjoying the video's Aly! Also glad the cap polarity tips helped.
Gorgeous work! And, very educational video. Thank you!
Thanks Christopher!
Very well done and looks super impressive.. Your work is top quality too 👍👌
Thanks Taz!
That looks great,good job.
That series of Akai was great quality, later series were more plastic cheap garbage.
smbrob I do agree!
You ever thought of doing a column for Nuts&Volts magazine.... or have you? I like the way you showed how to solder smd's and the CB layout is very professional.. Great video.
Re visiting this video two years later, still an amazing job 👍
It's a real pity that you didn't put a dummy load on it and pull out the oscilloscope for some performance measurements! Would have been great to see how the old girl was doing!!
ausome green LEDs,grate job. LEDs are no. one!!!
Man you sure know your stuff, i got lost at about 2 minutes,lol,the Amp looks bad ass too,awesome!!
Did sort of the same with a Toshiba RT8710S to light up the tuner scale and strongness indicator (there was no light at all). However I used some warm white LEDs (of christmas decoration) to mimick the light of real bulbs. Personally I love the warm colors, such as warm white, yellow and orange. I think I had chosen yellow or orange to apply onto this model. But hey, that is just a matter of taste. Nice mod.
Paul, ever considered doing a time lapse segment? It'd be pretty fun to watch you populate that board (24:00). If it isn't too logistically intrusive perhaps give it a shot on a future build. I think it'd go over pretty well. At any rate I really enjoyed watching you tack those resistors on. I was wondering what your method for soldering surface mount components was for some time now. Glad I finally stumbled onto this restomod.
That's a good idea. The board I'm designing right now would probably fill a few SD cards.
Mr Carlson's Lab Sounds fantastic. Can't wait to see it, however you choose to present it. Thank you.
+OJ dude dude... just chill out. Upload your own vid and show us your skills.
Blackbird OJ dude is just Trolling, best to just ignore. He doesn't even know what he's talking about.
These have BEAUTIFUL sound, i also love my sony ta-636
that was a really great way to get rid of the incandescents in an amp.i have an older technics that is going to get the same treatment but in red and that purple that's almost uv in color on the volume slider.thanks for the application idea and layout. btw....great repair and build vids.best to be posted so far.great work and detailed explanations.
=dok=
+Gizmo Thewytchdoktor
Thanks for your kind words!
I will have to look into building this, and replacing the LED's I have in my desktop VU display. Maybe incorporating the driver circuit with this circuit too.
Thanks for the video. The job looks beautiful! I haven't tried to build my own PCB's yet.
Thanks for the comment Robert! Making PC Boards is relatively easy. I will do a video on my process in the future.
Mr Carlson's Lab
That's what people say. I mainly started learning electronics to repair devices as a hobby. Some PCB's are good and some are bad. On bad ones, my Hakko 808, even on 1, will lift tracks while removing components. How do you make the good ones so that the tracks take more heat and stick better? What is it that the cheap PCB's lack?
Robert Calk Jr. Hi Robert. The Hakko 808 is a good machine, it's just a little cumbersome for fine work. Temperature and "dwell time" or ( the amount of time you have the tip contacting the board) are crucial when working on PC Boards. Most newer PC Boards have "plated through holes" which join one side to the other. These connection holes add a lot of strength to the pad that your de-soldering. Older single sided boards are much more fragile due the single side construction. When de-soldering a double sided board, one must exercise caution not to pull the plated through hole out with the component. If this happens, you must now solder both sides individually, so really, your using the components leg to make the connection from one side to the other.
Mr Carlson's Lab
Thanks. I try to be careful, but some PCB's, especially on fake devices, are so cheap it's hard to not lift tracks. I'm not even going to fool with cheap PCB's anymore - just not worth the trouble.
I love my Hakko 808 - it is such a time saver. I can't imagine not having it. It's funny: even though it's not very expensive, I would probably go more postal on a thief trying to steal my 808 than if he was stealing my Fluke. lol
I made a few LED mods like this, but nowhere near this neat... looks like i have to step up my game now ;)
Great project and results, Paul.
I wish you had included a shot of the schematic, though.
Thanks Dave!
40 years on and those AM-2950 jobbies are still selling in the high $100's... used!
Excellent modification. I would put warm white lights lik
Nice job mr Carlson big thumbs up 👍
nice work, i also love older style amps they just have more grunt compared to the newer all in one....
Thanks for the comment Blacklce504! I tend to like the older style amps as well.
Rubber mat is called vexar. We used to roll it out on produce racks at the supermarket.
I'm making similar mod to my Technics SA-380S, original incandescent bulbs are still working. since 1982
Thanks Mike Rivera!
Ooh, good job on this.
Nice nice i have one too but silver ,the finished project actually looks like is part of the original system
That's an elegant panel lighting circuit. The other day durring the yearly "spring clean" (rusken) in my neighbor hood (Oslo, Norway), people can throw out stuff from their flats and leave them outside until a garbage/recycler truck comes (and then throw it on the truck). Someone had tossed a Tandberg Sølvsuper 11 (1973). I picked it up. It's not that rear in Norway, Anyway its not working and I'm gonna learn all it takes to get it working. I really like that your circuit ramps the lights up/down like that at power on/off (nostalgia I guess). I'm going to do something similar too. The voltages are different though on the incadecant. Three 5V bulbs in series and a bleed resistor connected to the 28Vac directly at the secondary side of the trafo. What would be the next touch to the circuit.. light fading in pace with the bass line ? :) Just kidding. I just remember the Sølvsuper back in the day did this when it was playing too loud.
+bwack
Thanks for your comment! Light's fading with bass is not good ...LOL :^)
:) Just figured out it's 2x15W into 8 ohms.
Been watching a few of your videos. I like how you describe everything in detail. You did an excellent job on that Akai. Well done. Subbed :)
dash8brj Glad your enjoying the video's. Thanks for your comment.... and sub too!
dash8brj
Second that, just discovered Mr Carlsons videos, I'm not even an electronics guy (software) and find I learn a lot from these videos.
Glad your enjoying!
I love these videos. No job to big or to small . you treat each project the same. Love your work ethic . Did you finish your Onan hook up to your home , would love to see how you attached the unit to your power box .I'm sure you did some modes on the installation :)
Hi Jerold. It's just about done, installing an electric fuel pump onto the chassis.
Mr Carlson's Lab Thank you. Hope you video the installation. I know it takes longer but I think it would be a valuable reference a lot of people are installing back up power solar or generator. Thank you either way
LED mod looks awesome!
soloban81 Thanks for the comment soloban81!
A quality job. Well done!
jix177 Thanks for the nice comment!
I did this modification on older Radio Shack and Uniden scanners and on some Pachinko machines
Bro! Your a Master,
Could you do a Tech Tip Tuesday on how to generally replace incandescent bulbs in circuit with LEDs? There is a lot of good info in this video, but I'd like to understand from a more fundamental point the science behind the conversion.
You do very nice work!! I love coming home at night after the house is quiet and listening to jazz with my tea and a good book! I own macintosh and even now the clarity and detail sometimes still surprises me! Have you ever heard of Dunlap Clark dreadnought 1000 power amps? Made in Waltham Massachusetts and would like to have them restored to factory condition by you? Let me know?
Oh! What a great processional job! But I "stayed on my hung" a little bit because you forgot to show us the circuit diagram of your dimmer board. Is your diagram published somewhere?
Hi Christian. Not at this time, I'm working on putting all my schematics and layouts on Patreon at the moment.
You can preset the printer to always print mirrored since you have a dedicated printer for PCB transfers.
+rimmersbryggeri
That decision is made in the CAD program. For double sided boards, the back side isn't mirrored, the top side is. So it needs to remain a decision between board work.
Yeha your right because the content is mixed The graphics are not flipped while the text within them is sorry I got a little confused there mirrors are confusing some times. Or rather you generate the graphics relative to them needing to be mirrored to begin with and not relative to the side of the paper they are being printed on.
Very good job, excellent.
Ricardo.
Ricardo B Thanks!
brilliant video as always
Gahh I wish this was a kit, I don't have the knowledge nor the equipment to accomplish this. I just picked up an Akai AM 2650 and the lights don't work at all. Seems kind of pointless to replace the existing lighting when it won't last long term. Great job by the way looks amazing!
Beyteful job lovely results but a lot of effort how much would you charge for that work and parts ?
AESOME! What would it take to alter it to the voltage needed for a Yamaha cr-2040 and maybe simply solder pads instead of LED's so that wires for the 7 replacement LED's wires can be attached?
Hi again Paul. Regarding the transistor pack in the circuit. I think you said in the video or comments that they are run in linear region ? Are they configured as constant current drivers? Perhaps as emitter followers to buffer a control voltage ? I'm planning to do this myself soon. I've fixed my Tandberg Radio. It had a production fault.
Beautiful work!
Hello!
Are you varying the current or the voltage when you dim the LED's to achieve the smooth dimming effect?
Thanks! Keep up the awesome videos!
Is that cabinet/drawer liner material under the circuit board when you're soldering? That is a great idea to keep things from sliding around
good job. why no smd led? which ic you used?
fantastic work youre a genius
Awesome! I would not complain if that was in my AV cabinet... (I might actually have to put the glass panels back in the doors. :-) )
Great video, with lots of useful info! Do you know if LEDs were much more expensive until around the mid-to-late 80s? I ask because I've been replacing burned-out indicator bulbs with LEDs in a lot of vintage amps & receivers lately, and I've found that everything made before, say 1985, used LEDs very sparingly. For example, I just finished working on a Yamaha M50 amp which only used LEDs for its power meter. Every other light, including the power indicator and the 'protection' light (a thin, red, translucent strip of plastic which would've been perfect for a small LED) was an incandescent.
Shmeh Fleh LED's back in the 80's were not bright enough for many dials. The really bright ones were very expensive. Now they are cheaper than incandescent bulbs. Unfortunately today, many designers (engineers) design the surrounding circuit to max out the brightness, which is why you see so many failed LED's.
I've personally never run across a failed LED, but I've seen plenty of modern electronics with obnoxiously bright ones, particularly since blue became a popular color to use. On a related note, adding the ability to dim the LEDs on that amp was a really good idea. A few of my own LED conversions came out a little brighter than I wanted, but I'm too lazy to open them up & swap in a bigger resistor or whatever.
Mr. Carlson. Wow in one word. WOW! My retro heart beats like a drum after seeing your video. Is this board available for an Akai AM2800? It is similar to the AM2950. It only misses the volme knob lighting because it is an older amp. I cannot find bulbs, because of the high voltage, this would be a great solution. Chapeau!!!
Congratulations, very very good. Thanks
+jose carlos sanchez Thanks Jose!
Thank you Mr. Carlson. But you went for ~30 minutes without ever revealing what IC and what dimming circuit you used? NE558 quad timer? PWM dimming?
The IC has linear pass elements in it, no PWM. PWM is noisy.
A fine bit of engineering!
Thanks for the comment Ken!
At what point whould you consired this project overenginering ? Perhaps hot spare auto replacement leds ? And dont forget to put photoresistor to auto adjust brightnes, with A/D converter and arduino averaging 3 photoresistor inputs on time series multipole Butterworth filter with left to right and right to left brightness increasin option, and as safety faeture please consider voice syntesizer " maximum brightnes exceeded system disengages " that whould mix well with Kraftwerk "I am operator of my pocket calculator" you can take it and calculate voltage drop to leds same effect...
Mr. Carlson, do you believe that an LED used in scenarios like this is superior to an original bulb? I read people sometimes complain that an LED ruined the aesthetic of their amp *but* I imagine that may be because they used the wrong LED and/or poor positioning?
There are a few tricks to make them look good. Once you have those parameters in mind, they tend to look better than incandescent bulbs.
It's GORGEOUS!! btw In a store there an Akai AM-U02 and an Akai AM-U03 both working and both for the same price. I'ld like buy one of them but Idon't know which is better. As far as I know AM-U02 is less powewrful (26watts per channel) but has a wider Hz range (10Hz-40kHz). ModelAM-U03 is a bit more powerfull (37watts per channel) but it has just 20Hz-20kHz
Hi Vinnie. Knowing what power level they took those measurements at is very important. Usually amplifier bandwidth is not taken at full power unless listed. 40kHz is well above our hearing by double and some, but the added headroom in the amp will make it produce the highs nicer. The 10Hz bottom end may be the 3dB down point, but it doesn't mean the sine wave is pretty. 10Hz is getting close to DC, and that takes some big parts. There is a good chance at a given power level, both amps may perform very close (frequency wise)
Thanx a bunch bro! So in a few words which one would you purchase if in my shoes? price is the same. On a hand there's the U02 - less powerful but with wider Hz range - on theopther hand there is the U03 a bit more powerful but with just 20Hz-20kHz. I don't know, but I get the feeling the little U02 is better as sound quality. A wider frequency Hz range is equals to a better sound IMHO, more vintage, warmer and more dynamic tone, more harmonics.
Here's two links with their specifications; put an eye and look at these please;
AM-U02 www.hifiengine.com/manual_library/akai/am-u02.shtml
AM-U03 www.hifiengine.com/manual_library/akai/am-u03.shtml
transformer are different,
AM-U02 www.google.it/search?q=akai+am-u02+circuit&client=ubuntu&channel=fs&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjWisXku93SAhVGxRQKHScABi0QsAQIHA&biw=1920&bih=901#imgrc=c9wnZeq_hnk5fM:
************************************
AM-U03 www.google.it/search?q=akai+am-u03+circuit&client=ubuntu&channel=fs&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj058bJvN3SAhWEtBQKHaaGBRQQsAQIHA&biw=1920&bih=901#imgrc=FI-lNzy_yyJHJM:
I need to log in to look at the schematics..... which requires sign up and ....all that. What kind of music do you listen too?
every genres. The point is frequency Vs. powerful. AM-U02 has less powerful (26watts per ch) but can go to 10Hz to 40kHz. AM-U03 is a bit more powerful (37watts per channel) but its own Hz range is worst; 20Hz to 20kHz
What kind of microscope do you recommend? Also wondering how the right one would be useful in situations where you have an elevated clamp...
AmScope would be a good choice.
Could you not have incorporated a photo sensor so to automatically match the lighting in the room? Nice work, enjoyed your video.
Hi Howard. Thanks for the comment!
I could have, but the problem is... Usually these are mounted in a cabinet or on a shelf of some sort. So positioning of a sensor is critical, or there is possibility of oscillation. Problem 2 is.... A Hole would need to be drilled on the exterior of the amplifier to facilitate that photo sensor. So The most stable choice was to have 3 VR's to adjust the dials separately for the most even, consistent light.
True, but an external light sensor which could be well placed. I did something the same on a Technics system where the display at night was way too bright. It worked very well, the sensor was placed on top of the bookcase that the unit sat on.
Keep up the great videos, many thanks.
Very nice job. why change the color of the lights. I admit it looks great, but I like restorations bringing a unit back to it's original glory. I really dislike Leds on Marantz. But as I said this really looks great, even in green.
Awesome work!!
Thanks Steven!
excellent! Could you please explain the circuit you used to dim the brightness ofof the leds?
Thanks
Charlie Pechiar Thanks for the comment Charlie! I will probably do a video on the circuit build in the future.
Mr Carlson's Lab My Heathkit AR-1214 is still playing without any mods after 30+ years except I noticed the bulbs have all failed. This would be a worthy project and looking forward to the circuit build. Since it's never been turned off in the past 20 years, except during power outages, should I be concerned about filter caps?
hankus253 Hi. I sure would be concerned, especially those Temple capacitors. 60Hz is a lot easier on those capacitors than the frequencies of these new switch mode power supplies.... But they are still well past their due date.
Hi..Great Vid! ...I have a black Akai AM-2650 myself which sounds awesome connected to my restored Garrard zero 100 sc turntable. Only problem is power level meters and lights not functioning... I've ordered some new bulbs as I quite like the old skool incandescent warmth. Is there a fuse in the meter circuit somewhere? or will I need new meters...HAs anyone else had this problem and can give me some advice?
Paul, is there a chance to duplicate your design for my old Yamaha amp with bulbs, I really like that green Alien color you picked... Thank you for awesome inspiration from all of us.
It's a shame there was no shot of the board underside. Also I guess you could drill some holes in the lid and supply the customer with a trimmer for home adjustment of the brightness!
Very Interesting and informative Video, is the schemaitc available for this dimmer circuit, or did I miss seeing it? Interested. Thanks Lloyd - WA9NLA
+llsdigitek
If I do another, I will post it on the white board. Merry Christmas!
Nice video and explanation. I totally respect the skills. Thank's !?////////////////////////
Question : what or how do you safely discharge caps? It might be simple 101 type of stuff for you but I was hoping to hear your thoughts about this. And do you have the same approach regarding discharging internal high voltage components in tube products?
You can use a regular 60 watt incandescent light bulb!
Where can one buy a 9 volt replacement bulb to retain the stock design?