On Dec 5, 4:02 pm, "Arfa Daily" wrote:
wrote in message

...



On Dec 4, 6:11 pm, "Arfa Daily" wrote:
wrote in message

...

It seems to me that the output stage is broken. How could I proceed if
I don't find the service manual?

Before doing anything else, check the rear panel for a set of loop thru'
connectors for going out to a sound processor of some description. They
are
usually 4 x RCA phono type sockets, and may be marked either "Processor"
or
"Pre out - Main in" or something very similar. There is often a thick bar
silk-screened between them to indicate that they should be linked. Very
often, an amplifier will arrive on the bench with exactly the symptoms
you
describe, and the original factory-fitted linking bars missing. Usually,
the
person is a 'new' owner who has picked the item up second hand, and
doesn't
realise that the sockets need to be linked. If you find it to be the case
on
this one, all you need is a short stereo RCA to RCA lead, to patch them
back
together.

Arfa

Thank you for your quick reply.

Your guess was indeed spot on. It works very well now

Now there is two smaller problems. First the balance controller is
noisy. I'm going to try to clean/replace/bypass it. The phono input,
however, gives a large amount of noise out even with volume turned way
down and nothing connected to the input. I guess this means that the
phono preamp is broken. Would just disconnecting the preamp circuit be
a reasonable course of action?

Thanks again for the quick and precise answer. It saved me a lot of
time!

/Rasmus

If you're not intending using it, it might be. Is the noise on both
channels, and is it controlled by the volume control at all ? Can you get
the noise to completely disappear, with the volume right down ? Bear in mind
that phono preamps do generate considerably more 'hiss' than the other
inputs, due to a very high gain stage being switched in ahead of the main
preamp, when "phono" is selected.

As far as cleaning pots and switches goes, these older units usually respond
quite well to a squib of good quality switch cleaner / lubricant. Make sure
that you find a hole in the pot casing that you can get plenty of juice
into, then scrub the control by rotating vigourously from end to end, for at
least 10 seconds.

Arfa

Thanks for the advice on cleaning pots!

The noise on the phono is present on both channel and affected by
volume. However, it is disturbingly high even with volume turned all
the way down. It also does not sound like a high noise floor, but
rather more like an uneven rumble.

/Rasmus