Hello,
Temperature off my P2200 is about 102°F without work. Is it ok ? Room Temparature is about 80°F.
Thanks, Eckhard
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Hello,
Temperature off my P2200 is about 102°F without work. Is it ok ? Room Temparature is about 80°F.
Thanks, Eckhard
I'm going to measure mine and let you know soon.Quote:
Originally Posted by paragon
Thanks Lee.:)
Checked the DC bias?
No, Bias is not checked yet. Maybe there is a drift out of bias range ?
I will check the whole amp later because of hum on the right during the first 10 minutes after start. I will change the old capacitors also.
Hum could certainly be dried up caps. Any thump at turn-on? That's indicative of too large a DC bias (idle current) or offset, which then may settle after the servo circuit in them stabilizes. I'm assuming they use the same/similar dc offset servo design as the later PC2002/M. There is an (nearly) unobtanium IC's in them that have a tendency to let things drift too much. As I recall, the guys over on AK have tried a few sources for them with little luck.Quote:
Originally Posted by paragon
I've seen vague mention someone has also modified them with a speaker protection circuit (they do not have like the PC2002/M) and some "audiophile" mods, most likely just better caps and replacement films for small value lytics in the audio path. Great amps when they run right, which is most of the time as they're pretty tough.
FWIW, my Adcom GFA-5500 idles at 110 deg F.
Lee,
I opend the P2200 yesterday and there is an other, different transistor in position for TR107.
I will use the 2N5550 now. Is it ok ? I may also use the 2SA970.
And i will add on an switching on delay with dc protection.
I will use the 13V AC Power to power the switching on delay.
Is it ok ?
brutal,
there is only an IC circuit which is driving the peakmeters. And if this is dead you canīt get no alternate.:crying:
Revisiting an old thread. I lost my infrared pyrometer, so no way to measure temperatures. Will buy another one when they are on special. Anyway, when pushing either PC2002 pr P2200 amps hard for 30 minutes, the temps of the radiators barely change. They are mild to the fingers.
I already had two amps out of four being checked out by Eaulive who is local. He will soon be a Yamaha expert, even if he despises those heavy amps... :D
Some speaker protection circuits can indeed be added. They would help get rid of the "bump" on start up and shut down. Also protects against DC. As for any query on the PC2002 and P2200 amps, perhaps you guys can ask Eaulive. He worked on four of my amps.Quote:
Originally Posted by brutal
Protection circuit
http://www.dadaelectronics.eu/shop/d...otection-delay
I was (still am) a big fan of older Quad amps. I have sevral modded Quad 405 and 606 power amps that I am thinking putting back on service as I love their deep bass when modded.
http://www.dadaelectronics.eu/Images...ds/DC Prot.jpg
http://img.photobucket.com/albums/v6...y/DSCN0975.jpg
Thanks Lee,
I put two Speaker Protection circuits on my old Yammi.
I used the 13V AC from the right and left circuit board
to switch on the speaker protections.
So i soldered little rectifiers to the speaker protections
and switched on.
Both 1A fuses are blown and there are 80 Volts DC (left+, right-)
at speaker terminals.
I think i inverted +- from the rectifiers.:banghead:
Which alternate power transistor do you use ?:confused:
ONSemi
MJ21194G x 6 (per amp)
MJ21193G x 6 (per amp)
They are push-pull configuration.
I bought mine directly off the US ONsemi website as a developper and purchased one - got five for free. ;-)
Lee
Thank you Lee,
I will try this and hope it works.;) You bought one and get five for free ??
The output transistors are most likely damaged for having amplified so much DC. But the problem most likely is upstream on the driver board. I suggest refreshing the driver board too.
Of course, i will replace all transistors and all diodes.