I have this same amp it was working and got knocked over while playing now it won’t work. Where do I start looking. The red power light does come on and the needle jumps momentarily at start up. Any and all advise would greatly be appreciated & I thank you in advance Thank you
You've done a smashing job for it's new owner, balanced and happy as larry :-D. Sounds like the transistors are matched nicely too. I sort of expected you to measure supply current to each pair of trannys, i've used that method in the past, just keeps the trannys in the design zone. But i dont know that amp so it may be very accurate in the translation of pot voltage to bias level. It tests spot on though, you seem good with amplifiers :-). My internet died yesterday, otherwise i would have watched you then :-(
Not much point measuring each transistor, since it's enough that just one passes enough current to prevent crossover distortion. NFB takes care of the rest. That said, I did match the transistors prior to installing them, just because I had too much time on my hands.
But the zero volt balance at the speaker does matter, matching devices is allways a good idea, you didn't waste time, you really didnt :-). You are a good tech, never allow anyone to tell you otherwise :-).
Ah, yes, of course. That's still usually handled by the NFB circuit, though. The tiny voltage differential in this one probably has more to do with some poorly matched resistors somewhere.
Background music is a no-go for me - I usually have my own music running in the background. I don't have any problems with opening / closing music tracks though.
The music is fine, not obtrusive and rather well done. Great fix on the bias pot! Where did get a hold of that HP distortion measurement set? I've seen many times, just curious.
Hi, let me ask you this, if you will: what do you think about those new transistor (sanken) available? Are they good choice? My Yamaha p2201 power amp has no original transistor outputs, so I am going to try some sanken new ones. Thank you very much indeed.
I own Yamaha PC2602 and one channel distorts badly and bios is 00.0 ☹ Could you please give me a hint what should I check in the first place on that amplifier board? Frankly I already checked all transistors, caps and resistors on that board and they seem to be up to the specks.🤔
Thanks for an informative video! I've got a P-2200, but unfortunately the stepped action on one of the channels have... melted away? The dial can be turned multiple full rotations. I think it's the only issue with the channel, do you know what the name of the part I have to replace is, and how difficult it is? I have kiiinda limited soldering experience... Cheers, and thanks for your videos!
That could be as simple as a broken knob. The actual volume control potentiometer is very special in these, you'd have to chase down a donor unit to find a new one, or replace it with a normal potentiometer.
Just one more thing: when I power it on it comes immediately that sound "thump" that goes straight through the speakers (I power thump). Is that normal? Is there anyway to solve it? I mean can it damage my speaker?
Great video - like the way you have mastered the 339A - I have an 8903B which uses same principal for measuring but easier to use I guess. One question: the distortion is so low on the P-2200 it seems it would be at the same level being put out by the 339A generator, which I expect to be around 0.0015% (-95db?) itself. Amps that I have worked with exhibit magnitude of order higher distortion so the the analyzer distortion can be ignored. When it is so low in this case how do you deal with what the amp is producing vs the analyzer? If you subtract in this case I am guessing that the P-2200 is really putting out much less distortion! Or does the analyzer do the math canceling its own distortion out? Thoughts?
The answer is simple, you're an order of magnitude off; 0,0015 % THD is not -95 dB, but rather closer to about -75 dB. Add that extra zero, and all your assumptions stand quite true. The "dry run" distortion of my particular 339A is somewhere around -95 dB. If I hook the sig gen output to the distortion meter, the needle drops to one or two points from the bottom of the scale, 0,0002 % or so when fed a signal close to a full scale deflection for the range, or 0,0005 % or so for a 1/3 or so deflection for the range. If I hook the sig gen up to my PC to measure the THD (without N, because the PC has too much noise to see it), it is below the performance of the sound card itself, which bottoms out at about 0,0004 % on the ADC side when fed with an almost full-scale signal. As such, I'm quite confident using my 339A to rate amplifiers down to about 0,0005 % (-86 dB) THD+N in most cases, or down to 0,0003 % (-90 dB) if I can achieve an output level that's within the top third of one of the 339A's meter range. The closest I've come to an amp which would challenge the 339A, was a Yamaha AX-590, which scored consistent
@@FFcossag Why does the specs sheet of the ax-590 says 0.015 THD (i assume at 1khz only) and you were able to measured 0.006 across all frequencies? Are they being to "modest"?
background music is a little distracting, doesn't really suit your content imo. it works better at decided points as opposed to a constant background level, say during timelapses or tests or what have you.
That seems to be the general idea. The track I used for this video is actually intended to be used only with the VAN2017 series, and I wanted to test out the seamless loops I made, as well as to generally test the waters for background music on the audience. It's pretty fun reverse engineering your music, btw.
theres very little of it youll be unable to seamlessly loop somehow lol, it'd be fun if you suddenly decided to try your hand at music as well, could have some interesting results.
you still got this ? Surprised it works !! That pot HAS to be 1k and you adjust it for 10mV across the test points CT and PE at this point also check the voltage is zero between CT and E.............. The idling current should be 21.2 mA for each power transistor post back if you didnt blow it up !
@@FFcossag They are a real pain those trimpots, always amazes me how they manage to stay so close to spec even after 40 years.....testament to the design and build quality of these things........ I only posted just in case you didn't have the service manual but they are easily got these days... Maybe you shouldn't have sold it, any regrets ? only askin, I would only sell mine if a PC2002M came up but unfortunately, The majority of them are 110v and a long long way away, do you think they are better? IN Ripoff UK,they add the shipping to the price then add another 30% on the combined amount so we have to pay duty on the shipping and to add insult to injury, the Royal mail steal it to collect the duty then charge you another 30 for handling it...... IM NEVER GONNA GET A 2002 ....DAMN !!!!!!
@@ianhuntington9056 I have P2200 and a PC2002. The PC2002 definitaly os an upgrade. I also have an M80 and although not as much punch as the PC2002, cleaner sound. Espesially when at high volumes. Then I have a trio of MX1000u's. These absolutley dominate the others. That being said, I enjoy them all.
The amount of current running through the output transistors when no signal is present. If there's no idle current, it'll sound like shit. If there's too much, you get a fireball.
These things still go for prices around 500€, so if you can get a decent price for it and don't use it yourself anyways, then go ahead and sell it to someone who appreciates it!
I think the music's a tad distracting, it sounds good as something for the background of a game (kind of reminds me of SimCity 3000 or 4), but for a repair vid, it doesn't "work" if you know what I mean... :)
Please! Please! Please! No more background music very distracting when I'm trying to concentrate and take in what you're saying, please no music on the next video, many thanks.
I'm not sure what you're referring to, but everything was certainly soldered before doing any fiddling, and I glued the pot in place as well. Mind that the mounting of these tiny pots on this PCB is never going to be perfect.
Love the 'Calibrated snake oil detector' label on the HP distortion meter!
I WANT IT!! so bad, so cool.
I have this same amp it was working and got knocked over while playing now it won’t work. Where do I start looking. The red power light does come on and the needle jumps momentarily at start up. Any and all advise would greatly be appreciated & I thank you in advance Thank you
Could be a solder joint became loose. Hope u got it fixed
You've done a smashing job for it's new owner, balanced and happy as larry :-D.
Sounds like the transistors are matched nicely too.
I sort of expected you to measure supply current to each pair of trannys, i've used that method in the past, just keeps the trannys in the design zone.
But i dont know that amp so it may be very accurate in the translation of pot voltage to bias level.
It tests spot on though, you seem good with amplifiers :-).
My internet died yesterday, otherwise i would have watched you then :-(
Not much point measuring each transistor, since it's enough that just one passes enough current to prevent crossover distortion. NFB takes care of the rest. That said, I did match the transistors prior to installing them, just because I had too much time on my hands.
But the zero volt balance at the speaker does matter, matching devices is allways a good idea, you didn't waste time, you really didnt :-).
You are a good tech, never allow anyone to tell you otherwise :-).
Ah, yes, of course. That's still usually handled by the NFB circuit, though. The tiny voltage differential in this one probably has more to do with some poorly matched resistors somewhere.
Background music is a no-go for me - I usually have my own music running in the background. I don't have any problems with opening / closing music tracks though.
Noted. There seems to be a big superiority of the "no music" camp, so it's gone in future videos.
Thanks for all the feedback.
The music is fine, not obtrusive and rather well done.
Great fix on the bias pot!
Where did get a hold of that HP distortion measurement set? I've seen many times, just curious.
I was lucky enough to be in the right place to grab a whole bunch of gear that was being scrapped by a local TV station.
What a nice old yammi.
I enjoyed your video :)
hope for more videos on troubleshooting amplifiers
They come whenever I have amps in need of troubleshooting!
Hi, let me ask you this, if you will: what do you think about those new transistor (sanken) available? Are they good choice? My Yamaha p2201 power amp has no original transistor outputs, so I am going to try some sanken new ones.
Thank you very much indeed.
Will you personally train me to be an electrical engineer. Will you allow me to move to Britain and house me for as long as it takes. Please
I own Yamaha PC2602 and one channel distorts badly and bios is 00.0 ☹ Could you please give me a hint what should I check in the first place on that amplifier board? Frankly I already checked all transistors, caps and resistors on that board and they seem to be up to the specks.🤔
Thanks for an informative video! I've got a P-2200, but unfortunately the stepped action on one of the channels have... melted away? The dial can be turned multiple full rotations. I think it's the only issue with the channel, do you know what the name of the part I have to replace is, and how difficult it is? I have kiiinda limited soldering experience... Cheers, and thanks for your videos!
That could be as simple as a broken knob. The actual volume control potentiometer is very special in these, you'd have to chase down a donor unit to find a new one, or replace it with a normal potentiometer.
@@FFcossag Thanks for the tip! I'll have a look into it!
I just got one of these the other day what's it worth thanks.
Just one more thing: when I power it on it comes immediately that sound "thump" that goes straight through the speakers (I power thump). Is that normal? Is there anyway to solve it? I mean can it damage my speaker?
Great video - like the way you have mastered the 339A - I have an 8903B which uses same principal for measuring but easier to use I guess. One question: the distortion is so low on the P-2200 it seems it would be at the same level being put out by the 339A generator, which I expect to be around 0.0015% (-95db?) itself. Amps that I have worked with exhibit magnitude of order higher distortion so the the analyzer distortion can be ignored. When it is so low in this case how do you deal with what the amp is producing vs the analyzer? If you subtract in this case I am guessing that the P-2200 is really putting out much less distortion! Or does the analyzer do the math canceling its own distortion out? Thoughts?
The answer is simple, you're an order of magnitude off; 0,0015 % THD is not -95 dB, but rather closer to about -75 dB. Add that extra zero, and all your assumptions stand quite true.
The "dry run" distortion of my particular 339A is somewhere around -95 dB. If I hook the sig gen output to the distortion meter, the needle drops to one or two points from the bottom of the scale, 0,0002 % or so when fed a signal close to a full scale deflection for the range, or 0,0005 % or so for a 1/3 or so deflection for the range. If I hook the sig gen up to my PC to measure the THD (without N, because the PC has too much noise to see it), it is below the performance of the sound card itself, which bottoms out at about 0,0004 % on the ADC side when fed with an almost full-scale signal.
As such, I'm quite confident using my 339A to rate amplifiers down to about 0,0005 % (-86 dB) THD+N in most cases, or down to 0,0003 % (-90 dB) if I can achieve an output level that's within the top third of one of the 339A's meter range. The closest I've come to an amp which would challenge the 339A, was a Yamaha AX-590, which scored consistent
@@FFcossag Why does the specs sheet of the ax-590 says 0.015 THD (i assume at 1khz only) and you were able to measured 0.006 across all frequencies? Are they being to "modest"?
is this amp the perfect match for the Yamaha NS 10M ?
No. It's too noisy and big.
@@FFcossagnoisy?
Hi there, just a quick question, i got a yamaha pc2602m with old age symptoms to fix, where in the uk are you located? Me Tonbridge.
I'm nowhere near the UK, lol. Sorry.
Every time you turned it on my lights dimmed.
also yes the bg music is good but maybe turn it down just a tiny bit so it's only really audible when you go quiet or speak softly
Thanks for your feedback.
good video, LOL!!! you lost me at the end I have to admit.
Excellent video. I believe I've seen you work with this amp before?
It was featured in one of my first videos.
I have a spare room like this
background music is a little distracting, doesn't really suit your content imo. it works better at decided points as opposed to a constant background level, say during timelapses or tests or what have you.
That seems to be the general idea. The track I used for this video is actually intended to be used only with the VAN2017 series, and I wanted to test out the seamless loops I made, as well as to generally test the waters for background music on the audience.
It's pretty fun reverse engineering your music, btw.
theres very little of it youll be unable to seamlessly loop somehow lol, it'd be fun if you suddenly decided to try your hand at music as well, could have some interesting results.
I've never been any good at original thoughts. Changing other people's work is my forté.
you still got this ?
Surprised it works !!
That pot HAS to be 1k and you adjust it for 10mV across the test points CT and PE at this point also check the voltage is zero between CT and E.............. The idling current should be 21.2 mA for each power transistor
post back if you didnt blow it up !
What? It's calibrated to spec and then I sold it. It's still running just fine, since it's in spec.
@@FFcossag They are a real pain those trimpots, always amazes me how they manage to stay so close to spec even after 40 years.....testament to the design and build quality of these things........ I only posted just in case you didn't have the service manual but they are easily got these days... Maybe you shouldn't have sold it, any regrets ? only askin, I would only sell mine if a PC2002M came up but unfortunately, The majority of them are 110v and a long long way away, do you think they are better? IN Ripoff UK,they add the shipping to the price then add another 30% on the combined amount so we have to pay duty on the shipping and to add insult to injury, the Royal mail steal it to collect the duty then charge you another 30 for handling it...... IM NEVER GONNA GET A 2002 ....DAMN !!!!!!
@@FFcossag those are wirewound preset pots.....carbon ones will burn up
@@ianhuntington9056 I have P2200 and a PC2002. The PC2002 definitaly os an upgrade. I also have an M80 and although not as much punch as the PC2002, cleaner sound. Espesially when at high volumes. Then I have a trio of MX1000u's. These absolutley dominate the others. That being said, I enjoy them all.
Hi FFcossag what's "the amplifier's bias" mean?
The amount of current running through the output transistors when no signal is present. If there's no idle current, it'll sound like shit. If there's too much, you get a fireball.
These things still go for prices around 500€, so if you can get a decent price for it and don't use it yourself anyways, then go ahead and sell it to someone who appreciates it!
Indeed. I prefer my Luxman gear any day of the week.
I think the music's a tad distracting, it sounds good as something for the background of a game (kind of reminds me of SimCity 3000 or 4), but for a repair vid, it doesn't "work" if you know what I mean... :)
Please! Please! Please! No more background music very distracting when I'm trying to concentrate and take in what you're saying, please no music on the next video, many thanks.
Please, don''t put music in your videos... it's horrible... Thanks!
Noted.
IscleGaming wow do you do minecraft fidget spinner mod videos?
WTF?
thats a crusty looking iron but anyways I would just snip off the pot leaving the legs as soldered in the factory and just add the new pot )))))
I suppose I should like this as well.
Well I mean you should, else you'd be getting ripped off.
background music is cancer, especially when its "royalty free gnu/music"
:^)
Noted, although I have actually licensed the use of this music through the copyright owner.
ff :3
?
As far as I can see that pot is moving in the PCB whenever you touch it. Solder it.
I'm not sure what you're referring to, but everything was certainly soldered before doing any fiddling, and I glued the pot in place as well. Mind that the mounting of these tiny pots on this PCB is never going to be perfect.
"a bit dicky," you say?
keep using music in your videos, thanks
fake news
The music is super annoying imo.
Liking as i hit play! ferst?
I want to see the beast in your closet ;)
oh murr
OwO