Quick ROG tri-vibe question

[ChrisKelly]

Hi guys

I've been experimenting with gating the output from a ROG tri-vibe through a 4066 ic. The switch is controlled either manually with a momentary button, or with a clock signal from a 40106 oscillator. 100k pull up resistor on the switch control to keep it normally open.

http://www.runoffgroove.com/tri-vibe.html

It works fine except for a kind of residual noise which is in time with the LFO and passes through the 4066 even with the switch open. The rest of the audio is blocked with no problems, but the noise persists.

I've tried adding caps to block any extra dc but this hasn't fixed the problem.

Is this something that could be fixed with extra components or just a result of using a 4066 to gate the signal?

Cheers
Chris

[antonis]

In the absence of your specific circuit shematic, I'd suspect power supply "problem"..

[ChrisKelly]

Thanks Antonis. I'll check decoupling caps are all correct and see if that helps

[antonis]

I should start from deleting 10μF cap on Vref out..
I'd continue with placing 100nF ceramic disk on LFO & U1b Vrefs..
Then, a 10μF and a 100nF near by positive supply pins of U3b, U2b & U1b..

When the above done, I'd open a (can or bottle of) beer..

[ChrisKelly]

Haha thanks again! I'll probably start by opening the can of beer and then make the alterations 

[duck_arse]

100k pull up resistor on the switch control to keep it normally open.

without a circuit to see, I'd say - 100k pullup on the 4066 control pin will keep that switch closed. naught for open, one for closed.

but without a circuit diagram.

[ChrisKelly]

Sorry Duck Arse yes I meant to keep it normally closed 

[antonis]

In the absence of your specific circuit shematic

but without a circuit diagram.

This thread ecoes..
(but not vibrates..)

[duck_arse]

In the absence of your specific circuit shematic

but without a circuit diagram.

This thread ecoes..
(but not vibrates..)

echoes ,,,,, echoes ,,,,, oo's ..... o's

[ChrisKelly]

Antonis - for the 100n caps on LFO and U1b Vrefs, are these connected to Vcc/9V? Like a normal decoupling cap?

[antonis]

Connect them as close as possible to respective pins or resistor legs..
(in decoupling manner, of course..)