Modifying a fuzzface circuit for glassy rolled off tone

[Tjstomp96]

Hi I am trying to mod my standard home brew fuzz face circuit pedal to improve the classic "glassy" tone on vol pot roll off.
I understand its related to reducing the input impedance/ interplay with pickups.
Any suggestions on Q1 selection (low hfe ?) or bias settings etc ?

Thanks
T

[Mr.Kite]

Hi,

I would try a few things:

- replace the input cap with a 1uF: this helps with the cleanup and also reduces muddiness with the volume on the guitar on 10. The lower you go with the value, and the better it will cleanup. Obviously this reduces the overall amount of bass, so how low you can go it's your choice.

- a lower Hfe Q1 ("true" Hfe, considering leakege if Ge is used) generally has a lower input impedance than a high gain one: this exacerbates the impedance mismatch of the pedal and leads to better cleanup.

- The bias for an ideal cleanup tends to be a little higher than expected: for Q1c I would shoot for 0,5-0,7V for Ge and 1,4-1,5 for Si.

Fuzz Faces are known for their "fantastic" cleanup, but IME almost all other fuzzes of the same typology (Sola Sound MK 1.5, Vox Tone Bender, Vox Distortion Booster and so on) are much more responsive to the volume setting on the guitar...

Also a 250k\100k vol pot can help, since it retains a little more treble (less muddy tone) and will reduce the out impedance a bit...you might have to increase the output cap to 0,05-0,1uF to maintain the bass response if you change the pot...

I'm not that expert but this is what I noted, hope this can help!

[jdom1984]

This interests me as I am making my own fuzz face pedal, well have been trying to!
What do you mean by "glassy"? I experimented with simply putting a pot before everything, I called it pre-vol or something like this, it can really smooth things out a bit. Also I had a pot that replaced the 100k resistor that goes between q1 and q2, turning this down removed a lot of the "pressure" and a bit of gain. Like reducing sustain a little...

I ended up with 6 pots on one version but called it satans anus so obviously my attempts were not for "glassy" more "assy".
Check out the thread I made a schematic and some of the pots might be of interest to you, kinda an experiment but it was easy to get a more clean tone. Don't bother with bias as this makes it more filthy!

[Tjstomp96]

Hi thx fr schematic and tips - by glassy think Hendrix Littoe wing / SRV Lenny near clean sound
Yes moding the feedback resistor with a pot interesting however i think the main trick is to mismatch the low impedance of the FF input ( lowering Q1 hfe) with the pickup.
Im still trying !
Cheers😀🎸

[Kevin Mitchell]

by glassy think Hendrix Littoe wing / SRV Lenny near clean sound

Single coil (non ceramic) neck pickup into a fender tube amp. Most Custom Shop or Duncan pickups get you close to that vintage bell tone. I've got 69 series in mine.
I probably played Lenny 100 times over once I built my deluxe reverb.

BTW - neither song has fuzz in it. The tone does not come from a pedal but rather the instrument(pickups), the player and the amp. My recipe hits the nail on the head - as it should since it's pretty much what Jim and Steve had used 

-KM

[Mr.Kite]

by glassy think Hendrix Littoe wing / SRV Lenny near clean sound

Single coil (non ceramic) neck pickup into a fender tube amp. Most Custom Shop or Duncan pickups get you close to that vintage bell tone. I've got 69 series in mine.
I probably played Lenny 100 times over once I built my deluxe reverb.

BTW - neither song has fuzz in it. The tone does not come from a pedal but rather the instrument(pickups), the player and the amp. My recipe hits the nail on the head - as it should since it's pretty much what Jim and Steve had used 

-KM

I think he just mentioned those tone examples as a reference: he wants a cleanup "close" to that tone, which is possible with a FF...Anyway Lenny is definetely neck+middle and Little Wing could be just the middle pickup, since Hendrix was a real fan of that position...

P.s.

Welcome on board Tjstomp96!

[Tjstomp96]

Thx for the replies guys - My basic setup is CS69s neck and middle into Blues Jr (Bill M) modded and yes you get close on Lenny etc however a rolled off Fuzz as i understand it gets that "glassy" edge that perhaps you get from say a Super Reverb etc matches. Also Jimi was notoriously picky about his FFaces ie selecting optimum bias etc for tone.
Pete Thorn recently did a YT vid demoing this.

[Tjstomp96]

Thx Mr Kite - seems a very knowledgeable forum👍

[Electric Warrior]

Try silicon transistors. They sound rather bright with the volume rolled down, but you may need to dial back the fuzz control a little for good clean up.

If you prefer germanium, OC44s will clean up with bright, glassy tone. Most have close to zero leakage, so you will probably have to pick some that have hfes around 100 or higher or they won't bias right in a stock circuit.

[Rob Strand]

I probably played Lenny 100 times over once I built my deluxe reverb.

BTW - neither song has fuzz in it. The tone does not come from a pedal but rather the instrument(pickups), the player and the amp. My recipe hits the nail on the head - as it should since it's pretty much what Jim and Steve had used 

IIRC, SRV use a particular/different guitar on Lenny and a couple of other songs because it had *that* sound.

Found this,
https://www.premierguitar.com/articles/srv-s-lenny-1

[pinkjimiphoton]

use a 50k-100k pot, a .022 cap and make a hipass filter in line with the input.  less bass = less fuzz = less distortion, more mids and highs.