Trim pot on a tycho?

[csmatt45]

Hi folks!,

If you were going to put a biasing trimer on a tycho, similar to the 10k trim often put on a fuzzface, where would you put it? I'm getting this farty thing on mine that sounds just like a poorly biased FF.

Thanks!

matt

[aron]

Well, I would first see if I made a mistake when building it. Please link to the schematic used and use the debugging link in this main forum to figure out what could be causing the mis-biasing.

The simple mods page linked off the wiki tells you how to add a bias pot.

[csmatt45]

thanks aron,

I know about biasing with a trimmer, as per Wiki. I probably should have worded my question differently. I just meant that if you had to pick one spot to put a trimmer, where would it be? I've built a couple tychos now, and I'm almost positive there are no probs in the circuit, I've tripple checked. I went PNP, A18 on the NPN, 2n6519 on the PNP pair. It sounds to me the same as it does when you mess wth the 8.2k on a FF, sounds cool, but when you dig it and hit the strings hard, you hear a crackly farty sound. Any suggestions?

thanks aron,

Matt

[aron]

Use a meter and measure your voltages on the good ones and the bad ones. That will tell you which transistor is not biasing right. Then check the collector resistor and also measure the base to make sure DC is not throwing the bias off.

[aron]

Oh and check your resistor values around that transistor.