Olson New Sound Fuzz - build report (Maestro FZ-1A)

[LucifersTrip]

I just spent a bunch of time tweaking an Olson New Sound. This should probably be relevant to the Maestro FZ-1A.
...and just like the FZ-1A, it's just as difficult to get right. My 1st choice of 3 transistors resulted in no sound at all. Slowly, after swapping out loads of transistors in each position and making a few changes, I got an excellent saturated fuzz.

Q1 actually turned out to be a 2SB175 w/ hfe 90 and ~ 100-150uA leakage
Q2 is 2SB439 w/ hfe 290 and ~ 500uA leakage
Q3 is Tesla GC511  w/ hfe 90 and ~ 200-300uA leakage

Q1 emitter voltage is -.42
Q2 collector voltage is -.77
Q3 collector voltage is -1.27

A couple notes:
After playing for a bit, the 3 above voltages change to ~ -4.5, -.65, -1.24 respectively.

The one thing that cost me some time was Q2. I was down to  2 candidates and couldn't pick one. Then I decided to read the collector voltage. Immediately when I  placed Q2 in the breadboard, the collector voltage read -.15  and slowly rose over a period of a few minutes, finally peaking at ~ -.65. When I put in the 2nd candidate, the same thing happened...so I wasn't able to get an accurate sound until it settled. The change in Q2 caused Q3 collector voltage to fluctuate ~ .1

I was getting only an average fuzz with my final choice of the 3 transistors and changing to the 3.25K and 7.25K sweet spots...But it came alive when I removed both the 100K and the fuzz pot and increased the 15K on Q2's base. The 15K (replacing the 100k and fuzz pot) is set to give max fuzz. There's actually less fuzz (and the circuit is quieter) with no resistance. I could have put a 20K pot there, but I liked the pot on Q2's base better.

I'm putting a switch to simultaneously increase the in/out caps to .0047uF. If I go any higher, it's starts getting a bit dirtier and there's less fuzz.

A couple small things. Like many who've built the FZ-1A, I'm not getting any great sustain on the high E string...though, I'm not getting close to any type of gating.

The high strings are a little harsh. It can easily be solved by rolling back the treble on the guitar or amp. Changing the in/out caps only increased bass response leaving the treble nearly the same, raising the 1uF's killed the tone, and small resistors on the emitters killed the fuzz.

Still, a cool one but not a cakewalk to get just right...

[LucifersTrip]