"New *3 knob *2sw Tonebender

[petemoore]

Shaping the Tonebender
 3rd knob is bias adjust.
 I wish I had room for a fourth, input gain...I had one on there, nice to have but it has a superb high gain tone.
 I got some transistors, 115hfe is in Q1, 75hfe for Q2, and 175 for Q3 , hundreds of combinations tried from 12 tested transistors.
 The bias Q2 knob, gain and volume on top of the box, trimpot for Q1...I'm happy I decided to put one there, a chosen fixed value would be as good.
 I have left the YAFF mod on the Q2 emitter.
 The TBP Switch is a 3PDT blue  :wink:, no affiliation, a friend of mine just sent me them from Honolulu, but I'm using only 2/3rds of it, if I can't tell when my Tonebender is on, something else is wrong. I figure no LED is just that much more time on a battery for TB circuit to use.
 The box is a Purple Psychadelic Owl Face transfer to a RACO.
 I thought I had it before, [TB] and did [but the bias drifted or], this time I'm quite positive again...lol...after running it at high gains, it seemed like it was 'mushing' out just a touch, and I noticed bias voltage movement...[I'm just relating, maybe I was seeing things...] at any rate, I've installed a reverse Ge diode across Q2 B/E junction, and it seems to be perfectly stabilized, [tone slightly affected, it's not supposed affect the tone so maybe I'm hearing things too].
 Transistors of near same gain were tried and found to sound different, NTE158's, SB175, FF and TB sets, and a few new ones I got from SB.
 Various gain Si's [40hfe 'up], even in Q1 with 470k bias from base to V+ were tried in all positions and then not used.
 Q1 makes a difference, quite noticable when the input gain [guitar vol roll off] is down a bit.
 I'm finding I like Q1 of FF within the recommended Hfe [70-90, the next hfe I could try is 149hfe, too high IMO.
 And Q2 of FF [Q3 of TB] can be higher gain than 130hfe, different tone of course but I like, I didn't mess around with anything over 2oo hfe.
 It's been a long Tonebender Journey, starting in another life, this is as far as I've gotten and I think I'm there...
 I've read of misbehaving Ge Tonebenders, I'd have to say mine has had a long 'to do' list...once done though...
 The Tonebender experience is too good for words.
 Just got back plugging it into the MkII...
 It was real easy to dial in a good tone, the box top adjust on the Q2 collector is very effective, too low' and it loses output and sounds mushy, too 'high and it sounds 'uncontrolled'.
 Switches on the guitar and vol knob work wonderfully, Lead tones available to be dialed in from the guitar are from Liberally Saturated to smooth sustain to 'slinky' [here I'm typing words that don't exist] two note leads or rythm punch tones.
 Rythm tones it's easy to dial the guitar for crunch, light crunch with more timbre, to just clean boost [if played lightly].
 All this couldn't be summed up but I'll try...:Dynamically Input sensative clean to crunch device of very high order".
 Once again the amp and I never sounded better  :lol: ..
 Tone Bending Machine if there ever was one  :wink: .

[Joe Hart]

What schematic and layout did you use?
-Joe Hart

[petemoore]

TB MkII Professional, PNP Pos Gnd Version from GGG.
 AISaid, has a YAff mod for Q2 [100ohm between E and Gnd.]
 ...and also has Axis Face mod, cap across the [470ohm/1k/IMCase *1k+ 150ohm with the cap across the 1k], I adjust this resistor to bring the volume control near up...the volume control voicing done by adjusting the resistor between Q2CR and Q3CR.
 aND aLSO  a reverse GE [B/E] diode trick to stabilize Q2.
 The E Bypass cap is directly to Gnd. but I bump up the gain pot by adding a small R between it and Gnd...something like 220ohm.
 I don't know I've ever heard a greater sounding Fuzz box than this on record or live....what could possibly be more fun than this?
 It even beats the Sundail !!!...now the Sundail has competition and must be rethought and compared to the 'best'...lol...er 'my best anyway.