Thing Modulator - More Freq Range ??

[solarplexus]

Hi,

I just built a Thing Modulator and I'm wondering if there is a way to increase the range of it.  I would like the high feedback notes to hit just a little higher to make it sound like a ring modulator setting I had in a Boss ME-33.  It's sooooooo close it would be sad to be able to get dead on!   

Any ideas ??

[solarplexus]

Also,

there is a bleedthough of a small high pitch whine... it's barely noticeable, but it's there... would a buffer take care of this ? I believe it would have to be after the effect... am I right ??

[Tim Escobedo]

Increasing the range is mostly a matter of fiddling with the RC components that set the oscillator. You should be able to get it to vary from sub audio to higher than useful with the right cap and a pot as the resistance.

Regarding bleedthrough, just to make sure, are you using the LMC567 and not the more common LM567?

If so, some bleedthrough might be tamed by fiddling with the RC power bypass circuit. The resistor and capacitor I specify are unusually large, which seems to do some voodoo that otherwise might not be done.

Some bleedthrough may be noticable when the circuit is bypassed, as the oscillator runs free in the background, and with true bypass scheme, the raw signal may remain at high impedance. The solution for this problem may be a buffered bypass.

[solarplexus]

I am using the LMC567...

Could you give me a ballpark to what value I could change the cap and pot ??

About the buffered bypass... how would I do a buffered bypass with a 3PDT??

[solarplexus]

anyone?

[Paul Perry (Frostwave)]

Could you give me a ballpark to what value I could change the cap and pot ??

I havn't worked with this particular circuit, but the way I go in these situations, is to just progresively double or halve values. (or as close as I can, dependign on what is available).
in this case, I'd halve the cap for a start (that will get the freq doubled) and again till you are happy, maybe that will be enough, dependign on what your need is at the lower end of the range.

[solarplexus]

and what about the buffered bypass ?  Do I need a buffered bypass or I can put a buffer right after a 3PDT switch ?