"Ross Herbert" wrote in message
...
On Thu, 07 May 2009 13:59:29 +0100, Eeyore
wrote:

:
:
:Arfa Daily wrote:
:
: Anybody got any experience of an Audio Telex Communications of Sydney
P.A.
: amp model AMIS 250 ? I am particularly looking for a copy of the
schematics,
: but any help with it from anyone who knows the model, would be
appreciated.
: So far I have only been able to find a user manual.
:
: As it came to me, the main bridge reccy had one limb s/c, and the wires
to
: it looked as though they had got pretty distressed from heat in the
past.
: With the reccy replaced, it seemed to come up ok, but had no output.
Signal
: is getting up to the front pcb from the rear one, and the signal
presence
: detector for channels 1 and 2 is working, as the channels 3,4,5,6 mute
relay
: triggers when signal is applied to Ch1 or 2. You can also see the
signal at
: the detector opamp. But that's it. There doesn't seem to be any further
: preamp activity at all. There is an 'insert' jack on the rear panel,
and
: this should carry preamp output, which it then links back to power amp
: input. There is no preamp out signal at this jack. Nor anything at the
'tape
: out' RCAs on the rear panel.
:
: One further thing. Sometimes when you switch it on, the output stage
very
: quickly runs very hot, and the bridge gets very hot, which I guess is
the
: problem which led to the demise of the original, and made the wiring
look as
: though it has got hot, so when this problem occurs, there's some
serious
: current going through the output devices for some reason.
:
odgy bias pot ?
:
:
: When it's doing
: this, there are no signs of any instability - in fact still no output
of any
: description. I would add that this is a crap lead-free product, and
every
: joint on the output board of course *looks* bad. I have not been able
to
: provoke the heating up problem when it is running cool, by any kind of
: disturbance, but with lead-free, in my experience, that doesn't
necessarily
: mean that the problem is *not* a bad joint, and that is still my gut
feeling
: about it ...
:
: So, anyone got any hints, tips or insights (or schematics :-) !!)
for
: this model, please ?
:
:Are we talking of the original Telex or another company ? Bosch picked up
Telex
:along with EV, Midas, KT and Dynacord and technically DDA although
they've
:dropped the brand.
:
:Graham


AIUI Audio Telex is purely and Australian company. I vaguely remember
buying
something from them back in the late 80's. These days they are part of the
Hills
group http://www.audiotelex.com.au/home/in...ageID=7&main=0

Yes, as far as I know they are an Oz company, and pretty well respected in
the field of 100v line PA equipment.

All of which still doesn't help me with my problem / need for schematics ,,,
:-\

Arfa