Thanks for this layout just what I was looking for after lockdown weeks of breadboarding tonebenders and those vintage enclosures from gapco ideal - really comprehensive informative blog thankyou
Hi Andy, just in case this is interesting or helpful. Unwilling to part with big money on some OC75 or OC81 transistors I got a bunch of cheap Russian pnp germanium transistors (low leakage) to try some tonebender circuits and breadboarded a mk i ii & iii but only the mk iii sounded anywhere close so i got a couple more cheapish 60s transistors that have around 300uA leakage and tried again. Mki and mkii worked but as expected without OC75s or OC81s don't have the gritty mids to sound right. The mk iii sounds very close to the originals with Q1 Russian MP42B, Q2 Telefunken OC602, Q3 AC132/01. I used voltage divider 220k/47k as 680k/100k sounds too smooth and not fuzzy and gritty enough for me. Cap values all subtly tweaked to get the balance of sustain and texture I was happy with, fuzz is set on full but I'm adding a bias knob as there's some cool rough and angry tone about 2.5v at Q3 Vc. I didn't favour the mkiii initially but there's lots of room to play about with the circuit compared to the mki and mkii.
Nice, thank you for sharing. The MKIII is certainly pretty forgiving when it comes to transistors. I was lucky enough to pick up quite a few OC75, 76 and 45s from a guy locally that’s into old radios on the cheap. Even grabbed a couple of NOS OC44 for $5.
I’ve tried a lot of transistors in the MKIII and my favourite is the OC45 - which supposedly don’t have enough gain or leakage for Q3. So far the 45s have all been quieter by a long shot and have a softer fuzzier feel. 75s, 76s and 81s were tighter sounding with a higher noise floor. I also got good results with Japanese 2SB series.
For the MKII it’s OC75s all the way for me. The first Supa Fuzz I made was roughly where I stopped. It was just a moment of this is the business... job done.
I’m still playing around with MKI circuits, partly because I’m waiting for the right enclosure before boxing them up, and I got distracted with other circuits. I had good results, but I did spend a bit of time swapping transistors on the breadboard to get it sounding right.
I agree about the mkII, OC75s are the way to go. Interesting about the OC45 on the mkIII, if I see one at a sensible price I'll give it a try. On the mkIII I'm still liking the process of swapping out components and hearing how it can affect the sound. I'm playing around with the final tone caps and resistor values right now. I've read some opinions about how the Darlington pair transistors used don't matter much or how to substitute a single high gain silicon Darlington transistor, but there is definitely an element of the final tone that derives from Q1 and Q2 and to my ears it's worth keeping with a germanium pair.
I have a MKIII breadboard set-up, which is handy for testing. For me the first two transistors do matter, and I've noticed differences just by changing one transistor. example: an OC76 & OC45 sounds tighter than 2 x OC45s.
How much it matters is personal opinion - usually still sounds like a Tone Bender, just a different flavour. My favourite combo is 220n and 4n7 on the output caps, which is used on D*A*M Fuzzsound MKIII.
Thanks for the tone caps tip. I tried that and some other variations but eventually returned to the stock settings, except for using a log tone pot and reversing lugs one and three to allow for some finer adjustment over the more useable low to mids.
Thanks for this layout just what I was looking for after lockdown weeks of breadboarding tonebenders and those vintage enclosures from gapco ideal - really comprehensive informative blog thankyou
ReplyDeleteNo problem Nick - happy to share. I'm on a bit of a Tone Bender thing myself at the moment.
DeleteHi Andy, just in case this is interesting or helpful. Unwilling to part with big money on some OC75 or OC81 transistors I got a bunch of cheap Russian pnp germanium transistors (low leakage) to try some tonebender circuits and breadboarded a mk i ii & iii but only the mk iii sounded anywhere close so i got a couple more cheapish 60s transistors that have around 300uA leakage and tried again. Mki and mkii worked but as expected without OC75s or OC81s don't have the gritty mids to sound right. The mk iii sounds very close to the originals with Q1 Russian MP42B, Q2 Telefunken OC602, Q3 AC132/01. I used voltage divider 220k/47k as 680k/100k sounds too smooth and not fuzzy and gritty enough for me. Cap values all subtly tweaked to get the balance of sustain and texture I was happy with, fuzz is set on full but I'm adding a bias knob as there's some cool rough and angry tone about 2.5v at Q3 Vc. I didn't favour the mkiii initially but there's lots of room to play about with the circuit compared to the mki and mkii.
ReplyDeleteNice, thank you for sharing. The MKIII is certainly pretty forgiving when it comes to transistors. I was lucky enough to pick up quite a few OC75, 76 and 45s from a guy locally that’s into old radios on the cheap. Even grabbed a couple of NOS OC44 for $5.
DeleteI’ve tried a lot of transistors in the MKIII and my favourite is the OC45 - which supposedly don’t have enough gain or leakage for Q3. So far the 45s have all been quieter by a long shot and have a softer fuzzier feel. 75s, 76s and 81s were tighter sounding with a higher noise floor. I also got good results with Japanese 2SB series.
For the MKII it’s OC75s all the way for me. The first Supa Fuzz I made was roughly where I stopped. It was just a moment of this is the business... job done.
I’m still playing around with MKI circuits, partly because I’m waiting for the right enclosure before boxing them up, and I got distracted with other circuits. I had good results, but I did spend a bit of time swapping transistors on the breadboard to get it sounding right.
I agree about the mkII, OC75s are the way to go. Interesting about the OC45 on the mkIII, if I see one at a sensible price I'll give it a try. On the mkIII I'm still liking the process of swapping out components and hearing how it can affect the sound. I'm playing around with the final tone caps and resistor values right now. I've read some opinions about how the Darlington pair transistors used don't matter much or how to substitute a single high gain silicon Darlington transistor, but there is definitely an element of the final tone that derives from Q1 and Q2 and to my ears it's worth keeping with a germanium pair.
DeleteI have a MKIII breadboard set-up, which is handy for testing. For me the first two transistors do matter, and I've noticed differences just by changing one transistor. example: an OC76 & OC45 sounds tighter than 2 x OC45s.
DeleteHow much it matters is personal opinion - usually still sounds like a Tone Bender, just a different flavour. My favourite combo is 220n and 4n7 on the output caps, which is used on D*A*M Fuzzsound MKIII.
Thanks for the tone caps tip. I tried that and some other variations but eventually returned to the stock settings, except for using a log tone pot and reversing lugs one and three to allow for some finer adjustment over the more useable low to mids.
DeleteNothing wrong with stock - I like both. A log pot does make sense with a 2n2 given the extremes of the rebel control have very limited use.
ReplyDeleteHaha. Rebel = treble. On my phone and still waking up.
ReplyDelete