Musical Fidelity e300 power amp trannys help :(

functioning!

hello roar, well i've rebuilt the amp and it is now working.
the to3 mje devices are stone cold though, bias pot is pretty much where it was - in the middle.

amp sounds a little thin too , or i could just be paranoid.

im pretty sure all the repair work i've done is ok, and i've tested all the components. rails are obviously fine and there is negligible dc offset on both channels.

when say check the bias across r47 do you mean measure straight across that res? because if i do i get 0mv , and it looks like r47 is in the signal path.

any other tests i can do to make sure all is ok? im sure my amp used to run a bit warm.......
 
well the amp is up and running but it definately doesnt sound right.
its not distorted but its definately lacking bass, and generally sounds a lot brighter and thinner than before.

also the large 10w emitter resistors no longer get warm at all, which im sure isnt right. the o/p trannys are on though and are getting warm.

anyone any idea what could be wrong ? thanks
 
well the amp is up and running but it definately doesnt sound right.
its not distorted but its definately lacking bass, and generally sounds a lot brighter and thinner than before.

also the large 10w emitter resistors no longer get warm at all, which im sure isnt right. the o/p trannys are on though and are getting warm.

anyone any idea what could be wrong ? thanks

Hi, it's been a few years, but I also have the same problem. Can you tell me how did you solve?
 
On my E100, after a careful check, I found some broken diodes and the BC327 / BC337 pair were only BC337.
I restored everything and now it works fine. The idle current adjustment trimmers work. A repairman advised me to set the voltage on the output resistors to 10mV which corresponds to about 21mA. Is it correct in your opinion?
 
@luciano63 - did you ever get an answer?

I'm in the same boat with a E300. I have set them at 30mV across the output resistors. The output transistors get a little warm, but not hot at that level. Other than checking with crap workshop speakers to make sure it was OK, I haven't really listened to it.

Given that its a sealed box with no ventilation, I'm reluctant to go any further than this. Any ideas?