Help Tracing a Top Gear - Fuzz Sustain

[FUZZTX]

Oh, ok! I thought that was 1M! I see now it's 3M3. Thanks!

Yeah, I thought the tone stack was weird. I'll work on corrected my schematic off your vero layout. I can understand vero layouts WAY better than traces on PCB's. Anyway, this has been a fun learning experience.

[Leon]

I built one of these some years ago, I can't find my 'good' schematic but I have my first draft somewhere... though it's badly drawn I should be able to decipher it :)

A couple of things.

My TGFS had a 3m3 across the diodes and one 330k coming from pin 2 and one 330k coming from pin 3.. then being tied together at boost/volume lug #1. Neither of these lugs go to ground.

Input/outpt caps were 0.1uf. The two caps on the tone were 0.01uf and electros were 22uf.

[j behan]

I built one of these some years ago, I can't find my 'good' schematic but I have my first draft somewhere... though it's badly drawn I should be able to decipher it :)

A couple of things.

My TGFS had a 3m3 across the diodes and one 330k coming from pin 2 and one 330k coming from pin 3.. then being tied together at boost/volume lug #1. Neither of these lugs go to ground.

Input/outpt caps were 0.1uf. The two caps on the tone were 0.01uf and electros were 22uf.

right, cool, that's what I had too, thanks Leon!
I hoped the small caps might be 10nf, I thought that sounded best too, 22nf were just a little dark.

can you remember if the last 20% or so of the boost control acted kinda funny, like it was adding a bit of extra presence?
it was the one thing I thought was a bit weird when I was testing it last night.

[Leon]

Here's a redrawn version of my first draft of the schem.

I had 22k's for the tone control resistors, but looking at the several pictures on this thread (one actually being my TGFS) I'm not 100% sure on that. I no longer have my original TGFs or last version of the schem... so this this schem is unconfirmed.

[FUZZTX]

Hey Leon! Thanks for posting the schem and component values!

Last night I traced j behan's vero and this is what I came up with:

[j behan]

both schems look good to me.

[Dr Tony Balls]

That's gotta be awfully low output. Does it just barely hit unity volume? Looking at it its basically the clipping stage from a tube screamer with a big muf tone stack after it, yet with no boost following either!

[FUZZTX]

both schems look good to me.

Great! Tracing your vero was lot easier than tracing the pcb!

Thanks again Leon for posting your schem!

I may try to bread it this weekend if I have time.

[analogguru]

both schems look good to me.

Great! Tracing your vero was lot easier than tracing the pcb!

Thanks again Leon for posting your schem!

I may try to bread it this weekend if I have time.

Then don´t use neither 2k2 nor 22k in the tone-control. The correct value there is 33k.

Feel free to compare it with this schematic:
http://analogguru.an.ohost.de/193/schem ... der_RI.gif

analogguru

[John Lyons]

Respectfully AG, that's not the same pedal value wise. Vref is different, feedback resistor, etc etc.