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AW: [Doepfer_a100] Morph controller is dead...

2009-07-09 by yahoo@doepfer.de

> My A-144 Morph controller seems to be dead. Is there a common thing
> that happens to them if mistreated that may kill them? I have thought
> about just swapping out all the ICs but the only dual OP-Amps I have
> hanging around are 4560's and not the MC1458 that are in them. Would
> the 4560's cause a problem? If that won't work, what is the repair
> procedure for someone in the USA?
>
> Thanks for any help or suggestions.
> James

The only thing I know that would kill the module is a wrong bus connection
or wrong power supply. The A-144 is a very simple circuit with three dual
opamps (1458,4558) and four pnp transistors (BC557/558/559). The 4560 should
work if it has the same pin out as the 1458/4558. I don't have the 4560 data
sheet available so I can't confirm it. If replacement of the opamps does not
help the next step should be the replacement of the transistors.

Best wishes
Dieter Doepfer

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