Carbon Black (again)

mdc

Member
Looks great! I'm interested to hear if you found any difference between the mojo and non-mojo versions.
What transistors/HFE did you end up using for these?
Also, those red electrolytics are very pretty.
 

Nostradoomus

Well-known member
Great stuff, you're pumping them out!

Thanks! I just finished up the circuit board for the Ashy Larry version. Changed all the 100n caps to 220n and the output cap from 2.2 to 22n just to see what would happen, sounds pretty beefy! Also used a 2n4401 @ 240hfe in Q2. Don’t think it really did anything haha
 

mdc

Member
I've seen a few Si tone bender schematics that use a higher gain 2N5088 in Q3 with 2n3903 in Q1 and 2 — the Farm mourning dove is like this as well. I tried this out on one of the ones I built and it does sound a bit more saturated I think. I also tried out some OC140 Ge and they give it a bit of a different character but IDK how much.

What's the theory behind swapping the caps?
 

Nostradoomus

Well-known member
No theory, just random tinkering. Well the output cap value I knew would have an impact, but the other two were just for fun.
 

HamishR

Well-known member
Do you notice much more noise with the carbon comps or are there not enough of them to notice a difference?

I just built one because you inspired me to! I used 2N3903s around the 120-140 hfe mark. I really like it! It's more usable than a Tonebender in some ways. Somehow I managed to bias mine so it gets a good vocal sound on single notes but has the lovely crackle to it with chords. I like the random weirdness and the fact it goes so low gain. This is pretty much a fuzz I've been looking for, which is so cool. It sounds big and solid at the same time as having some fabulous random crappiness - perfect. I only wish my build looked as cool as yours on the outside.
 

Nostradoomus

Well-known member
Not really much noisier than the film resistor version, no. There probably isn’t enough of them to make a difference! I left the Fuzz pot at B5K this time as I am out of C5K and I don’t mind it at all for the lower gain settings, it sounds cool. I only had a 5K trimmer so I can’t quite get it to bias properly, think I’ll swap that for a 20k multiturn and really dial it in.
 

HamishR

Well-known member
I was out of B5K pots and only had C5K on hand - and I haven't noticed any weirdness in the taper so it must work ok.

At first I couldn't hear much difference when moving the trimmer so I guess a larger value couldn't hurt. I think my bias is at something like 7.6V and it sounds great.

The Top control doesn't seem to do a lot either. It does affect the tone but not by much.
 

Nostradoomus

Well-known member
I think that’s the idea of the Top control, pretty subtle. C5K is best here, it all bunches up with a B5K but I don’t mind it too much!
 
Top