Hipster - sub for 25k trimpot?

[gomer]

I've got a 20k and 30k, so i tried the 30k, and i get signal but no fuzz. do i have to use a 25k trimpot? or should i try the 20k?

[jimilee]

You should get fuzz just not as much with the 20 and too much with a 30,you may have another issue

[gomer]

strange , with bias adjusted all the way one direction I get no signal, then as u turn it the it acts like a volume. I'll go over all my parts and see if i made a mistake.
thanks jimi

[midwayfair]

The trimpot is simply a variable resistor. As you increase the resistance between 9v and the collector of a transistor, the voltage at the collector decreases and the gain goes up.

Using a 20K or 30K there should not make a difference; you are actually looking for something pretty close to 5K-15K, so there's plenty of range on either side of the trim pot. In fact, if you're using silicon transistors, you would have a working pedal just sticking the trimpot in there and setting it in any old position, just maybe not a good sounding one ...

If you're not getting any fuzz, something else is wrong. You need to check the orientation of the transistors, take voltages, etc.

[gomer]

well i switched trans to 2n5088 ( originally had bc109) and the pedal seemed to work more like it should so i guess i need to play with different transistors.
thanks for the reply ya'll!

[midwayfair]

well i switched trans to 2n5088 ( originally had bc109) and the pedal seemed to work more like it should so i guess i need to play with different transistors.
thanks for the reply ya'll!

Hm. Double check the pinout on your BC109; make sure you had it in right. The little tab faces away from the trimpot (it's the emitter).

[jimmyjazz]

I got great results with a 10k!

[Bman40]

I just finished one yesterday with a 20k trimmer... seems to work fine.

BK