THING MODULATOR PROBLEM

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tedsorvino
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Post by tedsorvino »

Hi everyone.
I would like to ask you what do you think could have gone wrong after following this schematic- layout, and having problems with it

https://www.instructables.com/Ring-Modulator-Pedal/

I think the main problem is around the power supply.
I measure 1V on pin 4 of LMC 567(power supply pin) which apparently is too low for the IC to function properly, I think.
I've tried some different, ICs, some different 100k resistors and a couple of different 100uf caps - (could both my 100uf cap be bad??? I have a lot of older, slightly used, ones). All combinations give around 1V.

Just for testing, I isolated the IC and followed this slightly different schematic (as far as the LMC567 IC is conserned) just to test the IC.

http://aletheia.co.jp/kawaikoji/2010/04 ... %E3%83%88/

I had the same results. 1V. IC not working properly.

Then I fed that pin directly with 9V and it worked better on its own (second schematic), even if it was very noisy, but when combined (first schematic) it caused trouble on the op amp out.
Then I fed it with 5V on its own (second schematic) it was working well, with minimum noise and as a whole with the op amp (first schematic) the whole thing worked better (I feed the op amp with 9V just to test), but the signal was quite weak.

Any ideas ( if you 've tried this thing), where should I check? There are no guide voltages for pinouts so it's like a blind testing.
Is it worth it as a schematic - or should I try something better with an LMC 567 (I've got a few around)?

Thanks in advance

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