Help: Gristleizer became Whistleizer

[salicet]

Hello everybody!

I just finished building the Gristleizer with the PCB that I ordered here: http://musicpcb.com/pcbs/gristleizer/, everything works surprisingly but here's the hook:
Unfortunately I wasn't able to get a MAX1044 here in Germany so I used a ICL7660 as a charge pump and now there is a constant whistling in the circuit measured at 8 kHz. The noise gets terminated when I switch to bypass and it can also be eliminated when "Level" is turned all the way down. I tried several 9 V DC adapters with the same miserable results.

Now I did some research and found out that some people experienced problems with a 7660 as a substitute with the high frequent tone mentioned before.

My question is: is there a way to get around this or is a MAX 1044 a MUST have? The "drone" noise is quite recognizable and this must be fixed somehow. It turned out that the exact model of my chip isn't a "ICL7660 S" (as ordered), it reads "7660" without any number. Are there differences?

It seems that the the "1044" is quite rare (at least where I live) and it seems more expensive. Is there any other chance to eliminate the whistling?

Thanks & Best Regards,
Alex

[salicet]

Got the problem fixed by connecting pin 1 of the 7660 in the socket. It was recommended to DISCONNECT in the building document!
Anyway I would suggest that the author should correct this detail in the PDF...

Regards,
Alex