Hello Folks,
I'm servicing an Acram Alpha 3 amplifier. The amp gives clear and nice sound
up to a volume of around 11 o'clock on the volume potentiometer. Above 12
o'clock the amplifier give a "bad" distortion on both channels.
Has anyone an idea what that that could be? Almost all transistors have been
replaced already (I have the service manual and circuit diagram etc).
Looking for input and ideas on how to solve that problem.
Thanx in advance
Uwe

Sorry if this sounds like trying to teach you grandmother to suck eggs, but
check for clipping distortion with your scope.
It could be that as you have replaced most of the transistors that they are
now biased incorrectly especially if they weren't quite the same type or
rating, (there is quite a spec range especially from different manufactures)
but 1st check the power supply ensue that will deliver the power required
old electrolytic caps are favourite here.
You might be better off running this one on a different forum like
rec.audio.tec unless you have empirical proof that the distortion actually
exists plus mathematical explanation fit for, that would pass the Nobel
committee or else you may be delusional ;¬) .

"Uwe Surojegin" wrote in message
news:JnsSa.90888$GL4.26241@rwcrnsc53...
Hello Folks,
I'm servicing an Acram Alpha 3 amplifier. The amp gives clear and nice
sound
up to a volume of around 11 o'clock on the volume potentiometer. Above 12
o'clock the amplifier give a "bad" distortion on both channels.
Has anyone an idea what that that could be? Almost all transistors have
been
replaced already (I have the service manual and circuit diagram etc).
Looking for input and ideas on how to solve that problem.
Thanx in advance
Uwe