Color sound overdriver biasing

[PMowdes]

So biasing.  I still struggle to get my head around this.  I've done a bit of reading about linear amplifiers and I get the need for the voltages at C, B and E.  What I struggle with is when the circuit isn't straight forward (like in the big muff for instance).

I built the Colorsound overdrive on vero and it was fine.  I made a pcb and I'm having real trouble with biasing Q1

I used the schematic from Beavis audio



I've tinkered with R1 but I'm not getting much more than 1V at the collector of Q1 and it sound really gated.

Do the voltages at Q1 have a knock on effect on Q2 at the base?

I have a 104nu71 in Q1 and bc108's in Q2 & Q3.  do the hfe values of these need to be considered??

Thanks in advance

Phil

[PMowdes]

[PMowdes]

Ok, I found something useful

https://aionelectronics.com/wp-content/uploads/2015/05/aion-plasma-colorsound-overdriver-documentation.pdf