I made my first pedal! Question, though...

[6x2]

Hi everybody,

My name is 6x2 and I'm an alco... NO, sorry, wrong place.

Here we go...

My name is 6x2 and I finished my first Fuzz Face clone last night. It was a very painless proceess and the pedal sounds all right.

Empasis on the words ALL RIGHT...

There's a funny phenomenon when playing through the thing. When sustaining notes start to slowly die, there's a high noise floor creeping into the signal. It's not there when I'm not playing at all, only in the tails of notes...

Now, I have heard about this problem a few times from different people, but my question is can I modify it so that this goes away?

It's a PNP Germanium (AC128) circuit, from General guitar gadgets, here's the link.

Thanks,

6x2[/url]

[petemoore]

Tha'ts called 'gating', the transistor is not biased into the middle of the swing...so higher amplitude notes get 'pushed' through, but as the signal fades, the transistor begins to shut off, this causes 'gating', and the symptoms which you described.
 Replace the 8k2 resistor [the Q2 Collector bias R], and replace that with a 10k, or better 20k trimpot, and adjust Q2's collector bias.
 Connect the -DMM lead to ground of circuit, touch the DMM+ lead to Q2's collector, turn the trimpot until you see something between 4.5V and 5V on the collector.
 No trim pot of said values?
 Use a socket for that resistor [8k2].
 or, use a 50 or 100k pot temporarily, in that position [the 8k2's] and adjust Q2 collector for ~4,5v [or 'around' 1/2 of measured battery voltage], then without disturbing the value of the pot [don't turn the shaft after setting the pot's resistance to set the collector voltage]...measure the resistance of the pot...say it measures 6k2, and replace it with a fixed resistor value as close to 6k2 as you can find/build.
 To build a resistor of an uncommon or unavailable value...
 two 10k's paralleled = 5k
 two 10k's seriesed = 10k
 by 'building' the resistance, from resistors you can get odd values.
 Just put something in there that is about +/- 10% of measured value that gets Q2 biased to around 4.5V
 I'ts a good idea to try a pot in this position, at least one time, to see how biasing affects the circuit, and how varying the bias near to or out of the linear region works.
 This pot is surface mounted on some builds, but I like to just set it and forget it...it does impact the sound of the effect.

[6x2]

Thanks a lot for your answer!

I'm a newb when it comes to DIY'ing, so I'll be posting dumb questions in the future... I'll try not to be to dumb, though...

Cheers,

6x2