CS 1-Knob Fuzz Hi Vol Prob Questions?

[Dogbrainz]

I've breadboarded a 1-Knob Fuzz which sounds rad but way LOUD!!

I've tried upping the input resistor from 150 to 180, 220 which does little for dropping volume.
Anything higher drops the signal so much that you lose the Fuzz.

I'm thinking of the following solutions:

-Changing my BC190(b) and BC180(b) to 108 and 109 A's (not sure if that would help drop volume much though)
- Try upping the volume pot to 1m and maybe put another output resistor before it

Any suggestions or tips would be much appreciated.

Thanks

[Jero]

That's not an input resistor, but a feedback resistor for voltage biasing, and squeezing out more gain I think. You're affecting the rest of the circuit at that point, which you noticed. Something like your second solution idea is probably the best bet.

[fuzzhead]

HI,

Make sure that all your grounds are connected together, especially with the volume lug 1.

[Nocentelli]

Make sure the volume pot is log, not linear. It won't make any difference to the maximum volume available, but will put unity a little further around the dial. It's loud, but unity should be around noon with a log pot, perfectly useable imho.

[Dogbrainz]

HI,

Make sure that all your grounds are connected together, especially with the volume lug 1.

Thanx FuzzHead. That's the sort of thing I wouldn't have thought of, will check it out

[Dogbrainz]

Make sure the volume pot is log, not linear. It won't make any difference to the maximum volume available, but will put unity a little further around the dial. It's loud, but unity should be around noon with a log pot, perfectly useable imho.

Thanx Noncentelli.

Pretty sure I've used a Linear(a) pot, not Logarithmic(b). You're right, a Log(b) should help cause less vol gain on earlier settings.
The schematic and vero diagrams don't specify so I figured Linear(a)
I'll try out a Log pot as you've suggested

However, I haven't even turned it past about 1 (7 o'clock), and it's MASSIVELY LOUD, even with my guitar amp set super low.

I'm guessing that a yeah a Log(b) pot would cause a bit less volume increase towards the start of the dial and would help me out so I'll try that, but I think there's still such a huge volume increase that I'll probably have to add another large resistor before the pot.

Or maybe also try using a different set of 108 & 109 transistors that hopefully wont amplify as much.

I'm now thinking that maybe I've got 108 and or 109 transistors that's amplifying way too much so I might have to suss out re-matching new ones.
I thought only germanium ones needed to be matched but I guess Silicon ones can be inconsistent too?

Thanx again.

[Dogbrainz]

That's not an input resistor, but a feedback resistor for voltage biasing, and squeezing out more gain I think. You're affecting the rest of the circuit at that point, which you noticed. Something like your second solution idea is probably the best bet.

Thanx Jero. You're explanations are always helpful and easy to understand.

If I can't drop the volume enough with a higher value volume pot and adding a resistor before it, could it be a problem with the Transistors?
(it really is MASSIVELY LOUD) Even when the volume is dailed to less than 1 (7 o'clock) and the guitar amp volume is very low

Q) I'm wondering if I might have poorly matched Silicon Transistors that could be causing too much amplification?
I thought Germanium Transistors were the ones that are inconsistent but I'm guessing maybe Silicon can vary as well, depending on production

Would it also be worth trying differently matched Silicon Transistors?

[Dr Satan]

If it's really loud when the volume is "down", turn the volume up. You may have wired the pot backwards. It may be as simple as swapping the wires on the outer lugs of your pot.