Weird Big Muff Problem

[aeonMg]

Hello!

I have just built two muff:s from the GGG layouts. One GGG tuned version and one Triangle Version.
they both sounds great, but if i turn the vol to max and turn  the tone pot down
the sound totally clips and it gets dead silent on about half the way down. On both pedals this problem disapeared if i swhitched C13 to
a 1uf cap instead of a 0.1 uf. Does anyone have an explanation for this weird behaviour?

Thanx!

[CynicalMan]

If this happened on both of your pedals, I'd guess something to do with your capacitors or transistors. Other than that I can't shed any light.

[aeonMg]

I know. It's a bit of a mystery. I'm going to try to change all the caps, and transistors. I'm using 2n5088:s now witch i thought would work fine.
I´ve got a shipment of 5089:s coming in though, so i´ll try those instead . If the problem prevails, then i'll do a more proper debugging post with all the voltage readings, and maybe
someone have a clue.

Thanx!

[aeonMg]

Got it all solved now. I changed the transistors to 2n5089, all having a Hfe at around 460 and that did the trick.
The 2n5088:s i first used all had a Hfe below 300 which really sucks!

[John Lyons]

That's odd. Some of the big muff variants use 2N3904s which are much lower than 300 hfe often.