As of today, if you google up stuff like:
Mki tonebender transistors hfe and leakage
There’s just no way to get all the info on one page. People in the know are keeping their mouth shut as to what the best leakage and hfe combinations should be, to get an up an running mki.
I’d just save Electric Warrior from the bunch, an extremely knowledgeable guy who is not afraid of sharing his views. He’s active on fsb and on the dam forum.
Now this pedal.. There’s no easy way to pull it off.
You think you’ll go the easy route and buy a tested, measured set of mki trannies online? Ok, no. Dont do it. The build will sound shit. They dont even come close to the ideal values.
Measured set 1: “compatible subs”
Q1: 2N404 (how original) hfe 81 lkge 0.04 (yeah, right)
Q2: 2N404 hfe 136 lkge 0.12
Q3: 2N404 hfe 93 lkge 0.00
I also spent more money on a set of mki matched OC75s: same story.
I made a couple of clones in the past, using these matched sets, just to review them again the other day to find the bitter truth: no sustain on notes up the fretboard. Fail.
Ok so i broke one of the clones open, socketed all the transistor points with alligator clips and i plunged into my collection of germaniums.
This idea on my mind:
John Barry’s guitar player asked Gary Hurst to increase the sustain of his Maestro FZ1 pedal. He modded the pedal, and the first Mark One Tone Bender was born.
So why people are still undecided (me for one until today) wether the mki should have sustain or not? Why the posts of builders asking “is this pedal supposed to sound like this or not?”.
Ok we have very little evidence of still working mki pedals, and we are all accustomed to the youtube links to listen to those. Pedals age, and they do not sound as they used to, when they were new.
But what about the recordings? Well, can you recognize fuzzes you hear on record? I think i can.
I can recognize a FZ1 from a FZ1a when i’m listening to it. Same thing with a Fuzzrite.
Put these people, the players, on the map. British freakbeat. Ok most of them used british pedals. Tone Benders. These bands never toured the States, the money they had, went on clothes, and maybe a better rig, for sure not on a US made pedal-ok maybe some of them had bought a Maestro in the wake of Satisfaction.
Also, they sound way more obnoxious than american garage bands, save maybe the texans- that in my mind switched to the more aggressive, silicon fuzzes earlier than anybody else, because of the temperature boiling their gigs.
American bands were looking up to Great Britain up to a certain point. But not the other way round unless you were a top player that visited the other side of the pond enough to be influenced by the vibe.
Americans were into the Yard-Birds big time.. The Litter sported the open tones of oc75 induced harmonics of the Tone Bender on their signature regional classic Action Woman-complete with Yardbirds style rave on, and thats 1968, a few months shy from the Zeppelin’s telecaster-and-possibly-a-Bender-into-a-modded-HiWatt debut.
You wanna listen to some Mki? Get the British Freakbeat compilations and dig.. there may be some.
Maestro FZ1/ Tone Bender Mki: high treble content, dark british amps, loud and with lots of sustain to cut through the mix. Think Baby I Go For You by the Blue Rondos, or Ronno. Like an half cocked wah. No velcro like the Maestro, but still based on the Maestro. Resistors to open up the sound.
I’m delving into the idea of the possible Maestro modification: putting an OC75 on q1 as a driver, and leaving 2N270 on q2, q3, on a mki build. After all, the original q2 and q3 in the mki are two 2G381, a random torrid germanium transistor never to be heard of again. Same as the 2N270.. probably the cheapest parts they could find.
Im going back to my Maestro builds, and an old geofex article.
–q1 must leak to activate q2, q3 leakage means sustain. If i remember correctly..
Here is my build:
Q1: oc75 hfe 78, lkge .32
Q2: 2N270 hfe 108, lkge .21
Q3: 2N270 hfe 401 (!!?!)*, lkge .66
*now a value like that should give you an idea of how shitty a transistor that is.
Don’t hunt for 2N270s. It’s not worth it. You’ll end up with a hole in your pocket and no satisfaction. Their specs are all over the place. And they dont sound like they measure. I went through a large batch of Fairchild 2N270, at an excellent price, and sorting them out has been hell. Thank God i have only about 20 RCAs, i keep them locked, they look nice and fat in their new old stock boxes and i will never use those. But they are the same. No quality control, folks. Or rather.. those were the times.
You can achieve the same results using other leaky transistors. Dont worry about the tone, the layout provides the tone on this one.
Dont change the layout values: leave the 470k resistor there.
Keep q1 hfe at round 70-80, leaky, q2 hfe in the 90-120 region, with leakage, and q3 not over 100 but it should leak loads.
😉 good luck.
A video will soon follow..