freestompboxes.org

I've been experimenting with this circuit and have found that it's kinda like the Tone Bender MkI. What I mean is that it can be tuned in similar ways. For example, the 470k resistor on Q2 base can be tweaked to either increase or reduce the distortion. If your transistors don't have enough leakage, you can sorta "cheat" by adding resistors to the B-C junctions of Q1 and Q3. Not really a "purist" approach, but it will work. If the transistor has too little leakage, it won't pass signal.

;;

Link to the original demo record...

Hello everybody, il would be really great if someone who owns an original FZ1 would be so kind to share:

1) Exact board size;
2) pictures (or description) of the bracket holding the circuit board, and how it's mounted;
3) how the input 100K resistor and 0.01uf capacitor are arranged;
4) circuit voltages.

For anyone interested I made several ones and found a fool prove way to make them:
-the 1.5V seams to be the best and most forgetful one
- transistors MP42B and GT402E are the best I found for replacement, (Personally I use a mix with MP42B,MP42B and GT402E). I bias them with a trimmer at C2 and C3.
-Even after many tries the single 1.5V battery works better than any alternative of lowering voltage on a 9V supply or battery (or I'm really bad at it)!
Have fun!
Ben

jreeves47 wrote: ↑04 Mar 2022, 19:19

Blues1911 wrote: ↑02 Mar 2022, 12:15 Hello everybody, il would be really great if someone who owns an original FZ1 would be so kind to share:


2) pictures of the bracket holding the circuit board, and how it's mounted;

Yay! Mysteries n. 2 and 3 solved, thank you!
It would be really perfect if you could also share the exact board size and the approximate height and depth of the bracket.

BMS1971 wrote: ↑04 Mar 2022, 20:24 For anyone interested I made several ones and found a fool prove way to make them:
-the 1.5V seams to be the best and most forgetful one
- transistors MP42B and GT402E are the best I found for replacement, (Personally I use a mix with MP42B,MP42B and GT402E). I bias them with a trimmer at C2 and C3.
-Even after many tries the single 1.5V battery works better than any alternative of lowering voltage on a 9V supply or battery (or I'm really bad at it)!
Have fun!
Ben

Well it seems disputed whether FZ1 or FZ1A is better. FZ1 should be bolder, but of course the overall tuning is crucial for a correct response, and yes FZ1A variant seems to be more transistor-friendly.
Nonetheless I've tried various transistor combinations on FZ1 and they all work properly - despite what is credited around, FZ1 it is a far from impossible circuit to make it work, and in fact it will fire up effortlessly provided that you put in some transistors with the right attributes.

It is the same principle that we all should remember with other circuits, like Tone Benders MKI and MKII (which are all FZ1 derivatives/evolutions): while in smaller numbers respect to today's standards, we are talking anyway about mass-produced pedals, so they were built around what they have cheaply and widely available at the time, and conceived to work always properly with them (and consequently with whatever transistor showing similar attributes).
Fine tuning is a different matter, but be sure that back in the days they just solder in the transistors and check voltages and proper overall operation before the pedal was thrown on the counter for sale.

For FZ1, you just have to find some high gain and quite leaky transistors (350uA and more). The rest is up above to your tastes: it can easily happen (as it happened to me) that, after lot of readings, you would find the best combination at the very first attempt.

MK1 tonebender is much, much more difficult to get right... BUT the Supa fuzz MK1 having a fixed gain is far more simpler to get right. IMO
Ben

BMS1971 wrote: ↑08 Mar 2022, 18:22 MK1 tonebender is much, much more difficult to get right... BUT the Supa fuzz MK1 having a fixed gain is far more simpler to get right. IMO
Ben

I don't know, with Tone Bender MKI I've had more or less the same experience as with the FZ1: once you have the right transistors it's not so difficult to get it right, I personally reached a very satisfying result with just a couple of transistor swaps. What I can tell is that (in my opinion) Attack control on Tone Bender MKI works way better when jumpering (not removing!) the 1K8 resistor - without it I usually get a better progression in the pot run.

Supa Fuzz MKI is a different matter, Attack pot is replaced by a resistor which stuck it at max, the real challenge on it is to tame its boost, which is very wild and very loud, also considering that (like in MKIs) you can't count on guitar volume cleanup not even to modulate the gain, differently respect to MKII, where even on those who do not clean up at all, you can anyway reduce the distortion playing with the instrument volume: conversely, once you reach 9 with guitar volume when Supa MKI is on, the sound becomes dull and muddy, completely unusable.

I will try the pot in // next time with 1.8K. Thanks for the advice
Ben