In the context of Fuzz Factory, how much leak is too much for the AC128? Values inside…
- Thread starter kylewetton
- Start date
A - Omigod it took me like a full minute to realize those were 1s and not 7s, I was like “holy crap that’s an awful set of AC128s OHWAIT”
B - a good chunk of the Fuzz Factory is a Fuzz Face, so Fuzz Face rules are a good place to start
From http://www.geofex.com/article_folders/ffselect.htm
B - a good chunk of the Fuzz Factory is a Fuzz Face, so Fuzz Face rules are a good place to start
From http://www.geofex.com/article_folders/ffselect.htm
kylewetton
Active member
1 v 7
You and me both! I did also read somewhere that the Q2 leakage doesn't seem to make a measurable difference in the FF, so I'm hoping for the best in just that one pedal (the one with over 500 on Q2). I'm building 5 of them so this batch will all be used. I'll just need to test them out and see if I can hear any problems
kylewetton
Active member
Thanks, that definitely gave me more to read about. I’m curious what the op amps role is in a Tonebender MKII, I’m at the point of trying to absorb as much information as possible about this sort of thing, it seems related more to the power section of the circuit
Coda
Well-known member
Yea, that’s a voltage inverter. The OG was Ge/PnP. To run that circuit with most power supplies you have to flip the voltage…
Check this out: https://www.diystompboxes.com/smfforum/index.php?topic=120704.0
kylewetton
Active member
I read all of it, there’s a couple links I’ll check out within that discussion but honestly the whole thing was quite cringe, that OP was trying to engage in a discussion and everyone else was handwaving them off with “why wouldn’t it”, “of course it’s like that”, or “you need to know more”.
Coda
Well-known member
Well, I read for the info, not the personality. You would want to try and match the measurements of Q2 and 3 in a Ge Tonebender MKII: 70-ish hfe for Q1, and 120-ish for Q2. You don’t want it too leaky, but the stuff you posted in the OP should work. Some of those transistors would work great in a MKI Tonebender, or an FZ-1…
kylewetton
Active member
Yeah the first five the photo are ~75hfe and the second five are ~120hfe which is what I requested, but I didn’t also ask for low leakage
Yeah maybe next time but these are for 5 x fuzz factories
andare
Well-known member
In my very limited experience, high leakage in Q2 makes it bias at 7-8V instead of the usual 4.5V, which means it will have more treble while maintaining the fuzz tone - biasing a Fuzz Face that high makes it sound more like distortion.
It's TB MK1.5 vs FF.
In an MKII I want leakage so it sounds brighter - it's a 1.5 with an extra transistor.
For a Fuzz Factory I would use low leakage parts, however. It's already crazy enough. Anything below 100 is low leakage for me. I find these quieter and more stable.
It's TB MK1.5 vs FF.
In an MKII I want leakage so it sounds brighter - it's a 1.5 with an extra transistor.
For a Fuzz Factory I would use low leakage parts, however. It's already crazy enough. Anything below 100 is low leakage for me. I find these quieter and more stable.
kylewetton
Active member
Thanks for the insight, I wonder, can I change the value of a resistor on one of the circuits that has the 500uA leak to something higher to bring the bias back down?
andare
Well-known member
of course, just don't tell Mr. Vex
