S - Paul P32 amplifier

[MGR]

Hi to everyone
Has anyone by chance repaired an amplifier by the name S-Paul P32?I got this amplifier with both channels damaged,some of the resistors and parts are beyond recognition.It would be a great help if anyone has schematics for this unit.Attached are pictures of the unit.


Regards MGR

 

[TonyTecson]

Hi MGR,

any luck with the amp yet?

 

[Leolabs]

Looks like we need to reverse engineer it or get a schematic.

 

[audiomachines]

hello,

I hope this could help. This is a P22 Spaul Amplifier. This came to my shop today for service. Maybe you could get some clues. Observing your pics, the burned components are a rectifier diode and two resistors.

 

[audiomachines]

another pic

 

[audiomachines]

top view of the board

 

[audiomachines]

another top view

here are the arrangement of the components 1/2W 100 ohm resistor,
1/4W 4.7K ohms, 1N4007 with the cathode pointing at the rear of the amp then the busted 47uF/160V elec.cap Hope this helps

Best Regards,
Audiomachines

 

[Leolabs]

Looks like you got a damaged driver stage.Wondering is the output stage damage too???

 

[audiomachines]

no damage on the driver stage or the ouput, the turn on delay/dc protection ckt. is the problem, It takes 45 seconds for the relay to activate, While the "normal" is around 5 to 10 seconds.

 

[MGR]

Thanks audiomachines but I have sincescrapped the original circuit , I have reverse engineered it and I found out the topology used was Class AB with the output in series connection to handle the +- 100V supply.I have replaced it with a Class H design.

 

[audiomachines]

hello MGR,

So there is not much difference bet. a P22 and a P32 amp. Same stacked transistor ouput topology, same supply volltage, maybe they differ only in the number of output devices and price too

 

[MGR]

The SPaul 32 was ruined beyond repair because the technician who repaired it before used fake toshiba parts and this caused the destructive chain of events.So pls. beware of fake toshiba parts they are everywhere in RAON.

 

[Leolabs]

no damage on the driver stage or the ouput, the turn on delay/dc protection ckt. is the problem, It takes 45 seconds for the relay to activate, While the "normal" is around 5 to 10 seconds.

Possibly overvoltage/short problem with the protection circuitry.It should be easily fixed.

 

[audiomachines]

yap she's up and running, the timing resistor got "rotten" you can see tiny bulges on the body of the resistor, like some sort of rust bulging out. I replaced every resistor,caps,diodes and tranies on the turn on delay/dc prot. ckt. These amp is being used for touring I have to make sure it will not fail on the middle of a gig.