I just picked one up today that had an easy life in a local church. I'm fairly new at servicing and repairing amps/receivers; a hobby that's far more satisfying and rewarding than my humble IT job. I get the feeling I'll be watching many videos like these along with reading. So yeah, thanks for sharing.
thanks for another amp repair! im sure if the time ever comes to repairing my AudioSource AMP300 I will have no trouble in finding things to check on it! (it is a fair bit newer than this yamaha but should be slightly similar)
Not really on context, but the production quality has gone up quite a bit in the past years - cameras are crispy sharp, focus is faster than mine after a few beers .. and the audio is better than anything I’ve ever gotten I also see your winamp EQ is as it should be xD
As a point of reference and being a sound guy myself, you may find the following information interesting. Microphones can't clip as they aren't powered drivers. They can however be over attenuated which is more accurately the situation you had there in your shop. You'll only find clipping on the output side of amplification in the sense that either the amp will run out of headroom or the speakers will reach their x-max and have no room to travel any further. Your mistake is very common and I don't think any less of you for it. I just thought you might like to know before a troll who knows just enough to correctly speak ill of you. I really do enjoy your channel. I hope this helps...
Hi again. UPDATE:. Crack open the meter chip carefully, it has a normal pcb inside with a fet and 4558 op amp circuit, replace some of the parts inside for accurate meter readings, if one meter is more sensitive, remove the meter, cover and resolder the coil spring with a bit more tension. and clip off the excess which will only be a millimeter or so... I soldered the pair together on a variable psu to calibrate mine and get them both to scale properly with each other at the correct value. The meters are very accurate when they work properly and were a very expensive option back in the day. They are very high quality large movement meters and heavy. Probably would cost around £100 a piece at today's prices, they are spec'd at, 1Kohm, 20mA, 2v for FSD.........I hope this helps and I know the meters are cosmetic but finding 50db square law meters on amps these days is impossible and boy do they look fabulous.....These amps sound great too, some idiots tho tend to want to bias them high thinking they are getting near to class A.....geez some people are dangerous.....6 transistors on an 80v psu? High volts, high load impedance, 8 ohms for these, they will not stand high bias for long, trying to explain that you are effectively shorting a 160v psu thru with only 6 transistors, if they want a class A, buy a class A...full stop. Class A, low volts, lots and lots of transistors, usually 20 -30 for 250w pc....... I agree to bias these to just under 10mv which gives around 35ma thru each o/p transistor I think from the top of my head................repaired a couple of these in the past and still think they are one of the best amps money can buy if you are lucky enough to find one.....they are also better than the later models, the M series and PC2002 series......Simple design with small component count gives very little noise and distortion as you know..... I still have one on my main system at home and will never part with it, never, not even for 5 grand. Also fitted small white led's for the meter illumination as a little mod to replace the bulbs and looks good other than needing a diffuser to remove the "tiger" effect, working on that one. Nice vid and be great if you could post another Yamaha repair job, pref a pc2002m if you get one in....... Thanx, Ian
@@ianhuntington9056 I have a friend looking for 2 replacement meters for his unit. Are these unobtanium or might you know where replacements can be found? Thanks!
@@johnlyden7243 Unobtanium except the odd ones out of a scrap amp usually in the usa. I could maybe lay my hands on one from an old engineer guy I know, what is wrong with your friends ones? these things never break
@@ianhuntington9056 Ian, thanks for the reply! My understanding is a previous owner had someone work on them and messed up the plastic shafts (his words, I know nothing about them), so they can't be adjusted. Whether or not they actually do not work is unclear to me.
Please correct me if I'm wrong cause I'm just a novice but when adjusting the bias I saw a "-" in front of the reading. Wouldn't that be a negative 10mV? Thanks for the video.
That voltage is simply a current measurement over a shunt (in this case the emitter resistors of the power amplifier). Bias adjustment is also more aptly described (with more syllables) as idling current adjustment. The P2200 uses .33Ω 5W resistors IIRC so 10mV across one (the bias adjustment measurement points are across one) is 30mA through the output transistors at idle (no signal and load). The emitter resistor of measurement is in series with an output transistor that would only have current go one way (unless totally broken), from 0mA to 10A. Consequently the voltage across the emitter resistor would do the same and not change direction, so polarity can be ignored.
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.
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?
A tech at a PA rental place told me the 2200 didn’t have a protection relay for DC at the speakers, whereas the pc2002 did. The latter has the click you mention. I have researched it and there are aftermarket onboard relays available but you have to be a bit of a tech to DIY.
There should be no thump unless there is dc present, sounds like the caps on the boards need replacing specifically the larger ones as one or more passes signal and dc as well if they are leaky. The amp should be clean instant power on power up. A side note, they didn't have relays because back then and since the Amcrons of the 60s it was considered that if one or more power transistors went short they would instantly take out the opposing rail as well which would leave a complete psu short and blown power fuses without speaker damage and speakers were also protected by fuses. Relays were added in later amps so that any shorts or excessive dc at the outputs could be detected before the speakers were connected and could also be used to protect the amp from shorts rather than the speakers. Nowadays though relay boards can be bought cheaply from ebay etc and simply added inline with the terminals and use a separate psu.
The reason the meters are not scaling is because the springs have uneven tension on the meters, if you recalibrate them by offsetting the ZERO spring return through the panel you will find you can get them to scale but they will not sit at zero. the meters are replaceable though and there are lots of available options on the market still that do fit although you will need to measure the FSD of them for the replacement value, 1ma or 100ua fsd, not sure but you can then remove the scales from the old ones and put them in the new ones....
This thing is such a bad bitch... We've got 3 15' and 2 12' loudspeakers in our partyroom and on full throttle the p2200 brings them to punch against their cover :o Love this amp
I just picked one up today that had an easy life in a local church. I'm fairly new at servicing and repairing amps/receivers; a hobby that's far more satisfying and rewarding than my humble IT job.
I get the feeling I'll be watching many videos like these along with reading. So yeah, thanks for sharing.
Good luck!
@@FFcossag подскажите пожалуйста, как перевести р2200 в моно режим?
I enjoy your repair work as well as your BBC level pronunciation.
Thank you.
finely a video that is not a stream !!!!! keep them coming
I sometimes have time to do these as well.
Even if it wasn't really faulty, it still got a good servicing at least... :)
thanks for another amp repair! im sure if the time ever comes to repairing my AudioSource AMP300 I will have no trouble in finding things to check on it! (it is a fair bit newer than this yamaha but should be slightly similar)
Not really on context, but the production quality has gone up quite a bit in the past years - cameras are crispy sharp, focus is faster than mine after a few beers .. and the audio is better than anything I’ve ever gotten
I also see your winamp EQ is as it should be xD
As a point of reference and being a sound guy myself, you may find the following information interesting. Microphones can't clip as they aren't powered drivers. They can however be over attenuated which is more accurately the situation you had there in your shop. You'll only find clipping on the output side of amplification in the sense that either the amp will run out of headroom or the speakers will reach their x-max and have no room to travel any further. Your mistake is very common and I don't think any less of you for it. I just thought you might like to know before a troll who knows just enough to correctly speak ill of you. I really do enjoy your channel. I hope this helps...
i've used those a bit back in the 90's rave on :-)
You sure know your way with amplifiers, at least it's gotten a proper examination.
Hi again. UPDATE:. Crack open the meter chip carefully, it has a normal pcb inside with a fet and 4558 op amp circuit, replace some of the parts inside for accurate meter readings, if one meter is more sensitive, remove the meter, cover and resolder the coil spring with a bit more tension. and clip off the excess which will only be a millimeter or so... I soldered the pair together on a variable psu to calibrate mine and get them both to scale properly with each other at the correct value. The meters are very accurate when they work properly and were a very expensive option back in the day. They are very high quality large movement meters and heavy. Probably would cost around £100 a piece at today's prices, they are spec'd at, 1Kohm, 20mA, 2v for FSD.........I hope this helps and I know the meters are cosmetic but finding 50db square law meters on amps these days is impossible and boy do they look fabulous.....These amps sound great too, some idiots tho tend to want to bias them high thinking they are getting near to class A.....geez some people are dangerous.....6 transistors on an 80v psu? High volts, high load impedance, 8 ohms for these, they will not stand high bias for long, trying to explain that you are effectively shorting a 160v psu thru with only 6 transistors, if they want a class A, buy a class A...full stop. Class A, low volts, lots and lots of transistors, usually 20 -30 for 250w pc....... I agree to bias these to just under 10mv which gives around 35ma thru each o/p transistor I think from the top of my head................repaired a couple of these in the past and still think they are one of the best amps money can buy if you are lucky enough to find one.....they are also better than the later models, the M series and PC2002 series......Simple design with small component count gives very little noise and distortion as you know..... I still have one on my main system at home and will never part with it, never, not even for 5 grand. Also fitted small white led's for the meter illumination as a little mod to replace the bulbs and looks good other than needing a diffuser to remove the "tiger" effect, working on that one. Nice vid and be great if you could post another Yamaha repair job, pref a pc2002m if you get one in....... Thanx, Ian
my mistake, 30ma
@@ianhuntington9056 I have a friend looking for 2 replacement meters for his unit. Are these unobtanium or might you know where replacements can be found? Thanks!
@@johnlyden7243 Unobtanium except the odd ones out of a scrap amp usually in the usa. I could maybe lay my hands on one from an old engineer guy I know, what is wrong with your friends ones? these things never break
@@ianhuntington9056 Ian, thanks for the reply! My understanding is a previous owner had someone work on them and messed up the plastic shafts (his words, I know nothing about them), so they can't be adjusted. Whether or not they actually do not work is unclear to me.
Nice
Please correct me if I'm wrong cause I'm just a novice but when adjusting the bias I saw a "-" in front of the reading. Wouldn't that be a negative 10mV? Thanks for the video.
You can only get it to go one way, so it doesn't matter.
That voltage is simply a current measurement over a shunt (in this case the emitter resistors of the power amplifier). Bias adjustment is also more aptly described (with more syllables) as idling current adjustment. The P2200 uses .33Ω 5W resistors IIRC so 10mV across one (the bias adjustment measurement points are across one) is 30mA through the output transistors at idle (no signal and load).
The emitter resistor of measurement is in series with an output transistor that would only have current go one way (unless totally broken), from 0mA to 10A. Consequently the voltage across the emitter resistor would do the same and not change direction, so polarity can be ignored.
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.
Angels With Scaly Wings! :D (Awesome video, too!)
Anna is best dragon waifu.
These are still all over the place in Japan.
Lucky Japanese..... They are the 100v ones though so no use in UK, would love to find another one
What is that music you are playing?
All music in my videos is supplied by combatplayer, see the desc. for links.
Hello sir, do you sell battle toads?
Sir, Gamestop is across the street. We just have a broken N64.
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?
A tech at a PA rental place told me the 2200 didn’t have a protection relay for DC at the speakers, whereas the pc2002 did. The latter has the click you mention. I have researched it and there are aftermarket onboard relays available but you have to be a bit of a tech to DIY.
@@aeyb701 thanks.... that's exactly
There should be no thump unless there is dc present, sounds like the caps on the boards need replacing specifically the larger ones as one or more passes signal and dc as well if they are leaky. The amp should be clean instant power on power up. A side note, they didn't have relays because back then and since the Amcrons of the 60s it was considered that if one or more power transistors went short they would instantly take out the opposing rail as well which would leave a complete psu short and blown power fuses without speaker damage and speakers were also protected by fuses. Relays were added in later amps so that any shorts or excessive dc at the outputs could be detected before the speakers were connected and could also be used to protect the amp from shorts rather than the speakers. Nowadays though relay boards can be bought cheaply from ebay etc and simply added inline with the terminals and use a separate psu.
@@ianhuntington9056 thank you... Got it
The reason the meters are not scaling is because the springs have uneven tension on the meters, if you recalibrate them by offsetting the ZERO spring return through the panel you will find you can get them to scale but they will not sit at zero. the meters are replaceable though and there are lots of available options on the market still that do fit although you will need to measure the FSD of them for the replacement value, 1ma or 100ua fsd, not sure but you can then remove the scales from the old ones and put them in the new ones....
another option btw is to heat a very small pin and push it through the plastic for the needle to rest against at zero............meters fixed
Uneven output between sides, distortion, always clean the balance/unbalance slide switched in back as an easy place to start.
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.
Im in the UK near Lancaster, do you need help? I have the service manual for that
This thing is such a bad bitch... We've got 3 15' and 2 12' loudspeakers in our partyroom and on full throttle the p2200 brings them to punch against their cover :o Love this amp
I lusted for one of those when I was younger.
P.S. you said 50 years of abuse, it's 40, I have 50 years of abuse ha ha
Off by a decade is just 20 %, it's fine. ;)
@@FFcossag yeh....not quite as bad as the utube guy biasing one to get near to class A.......I wonder how long it lasted before it fried !
I can't see much wrong with that, other than the design could of had fine bias trimmers linked to the coarse ones.