ICL7660S and problems

[JaviCAP]

Hi mates, I wrote this on the new Rangemaster with inverter layout, but I think that is an interesting topic to be published here, so I' put it here too, and would like to read your opinions:

My experiences with the 7660S and its different configurations are not all ok:

- With the Klon, used as doubler, sounds great and no noise.
- With the Mutron III: sounds great, no noise at all
- With the OKKO Diablo: Infernal whine when set to 18v, totally useless.
- With a Fuzz Face: (as inversor) Noticeable noise, and tamed fuzz, not recommended.
- With a Tonebender MKII: (as inversor) Noticeable added noise and slight oscillation when gain is al high values. Not recommended.

So, in my opinion, this ic is not recommended at all with germanium builds as inversor and neither medium - high distortions as doubler. The only overdrive - disrtortion effect where I have had no problems, has been the Klon.

Of course, this is my experience but I'd like to share it.

[IvIark]

My good feelings about this IC come about because the only noise that I've ever had from them was when I ordered the ICL7660 instead of the ICL7660S in a Klon.

When I did the first layout for the ARC Effects B3 which was their Buzzaround, and before they started selling them I built a sample board with the inverter just as an experiment to check how well it performed.  I tested it with the inverter and with a battery in positive ground mode and couldn't tell the difference.  In fact I found the pic of my test setup



(I socketed the filter cap so I could try different values if I thought it tamed the fuzz too much)

I haven't done direct side by side tests with anything else, but when I have used them as inverters for other builds I've never had noise that seemed unusual for the pedal I was building.  So nothing seemed strange enough for me to bother trying it the other way and identifying the charge pump as the source of any problem.

That's why I've always been an advocate for them, the only time I had an issue was my fault for ordering the wrong one.

But this is interesting, I think I would like to check the pin compatibility and do a few tests with the LT1054 and MAX1044 as well as the ICL7660S and see how they stack up against each other for these things.