Thanks Dieter, So both LM324 amplifiers are identical Is it worth replacing the socket the chip plugs into

I guess I order one of the top two chips below:

http://www.rapidonline.com/Electronic-Components/Integrated-Circuits/Operational-Amplifiers/Operational-amplifiers/67379/kw/82-0228 source=googleps&utm_source=googleps

Thanks,
Jonathan

--- In Doepfer_a100@yahoogroups.com , <yahoo@...> wrote:
>
> > I just purchased a damaged second hand a-136 Waveshaper. Looking
> > at the PCB I think the module has had it's power conection hooked
> > up the wrong way around at some point in it's life. The chip
> > (75H21EK LM324n) that is hooked up to the amp knob via a yellow
> > wire has a black burn mark under it and on the reverse side the
> > solder is slightly blackened, as is the PCB.
> >
> > I guess the chip could be blown The rest of the module looks fine.
> >
> > How it sounds All of the knobs still have an effect although the
> > module only seems to produce sound in the negative range and the
> > ext.level CV inputs don't seem to do anything. It only cost £20
> > and still produces some nasty sounds!
> >
> > Any help would be great :)
>
> I'd recommend to replace the two quad operational amplifiers LM324. They are
> low cost parts and should be available for much less than 1 US$.
>
> Best wishes
> Dieter Doepfer
>