In article ,
Uwe Surojegin wrote:
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 gives 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

The level it starts distorting at has little to do with the volume
control setting but all to do with the input level. What are you driving
it with?

--
*Hang in there, retirement is only thirty years away! *

Dave Plowman London SW 12
RIP Acorn

Hi Dave,
I'm using a Sony CD Player (nothing special right now) .. but this should
not be a problem. It showed the same distortions already with a Denon 3560
player. By the way I'm using 8 Ohm speakers. So that should be acceptable.
Do you or someone else have experience with such distortions or clipping
around 12 o'clock on the volume poti?

Rgds
Uwe
"Dave Plowman" schrieb im Newsbeitrag
...
In article ,
Uwe Surojegin wrote:
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 gives 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

The level it starts distorting at has little to do with the volume
control setting but all to do with the input level. What are you driving
it with?

--
*Hang in there, retirement is only thirty years away! *

Dave Plowman London SW 12
RIP Acorn

In article , Uwe
Surojegin wrote:
Hi Dave, I'm using a Sony CD Player (nothing special right now) .. but
this should not be a problem. It showed the same distortions already
with a Denon 3560 player. By the way I'm using 8 Ohm speakers. So that
should be acceptable. Do you or someone else have experience with such
distortions or clipping around 12 o'clock on the volume poti?

What rms/peak levels of voltage and current do you read at the point where
distortion becomes evident?

What are the details of the waveforms? Music? Sinewaves? etc...

Do you know the sensitivity of the input you are using?

Slainte,

Jim

--
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