Found my holy grail...

[Ge_Whiz]

No, not the EH one, the distortion unit I've been searching for for years. One knob distortion control that goes from gentle overdrive, to fuzz, to metal, to insanity and beyond. And it is...



Tim Escobedo's Tripple Fuzz, with acknowledgements to Gary Burchett for the tip-off. I threw it together in two hours last night, with a high-gain (hFE 750) Zetex transistor for Q1, and a matched pair of hFE 300 BC549 and BC559 for Q2 and Q3. Not only does it sound great, it's fun watching the output on an oscilloscope as you turn up the gain - see your sine wave square off, then slowly turn itself inside-out. Sorry, it's the only way I can describe it.

Hoodah thort such a killer tone could be achieved with so few parts? And, best of all, it uses no electrolytics so it'll still be working when all my other pedals have died in 2010, LOL!  :twisted:

[audioguy]

Sounds cool- is there a schem and layout avaiable anywhere?

Thanks!

Audioguy

[remmelt]

google is our friend

[audioguy]

I found that too- but it has a different designers name.

[Ge_Whiz]

http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

See also http://www.diystompboxes.com/sboxforum/viewtopic.php?t=23731

[Gary]

Ge_Whiz,

Isn't it an awesome circuit?!?  I love Tim's work and I think Brian is a fan of his, too.  Tim is underappreciated.

Did you build the "Trimmer-less version"?  I haven't tried that yet, but will after finshing the present projects.

Regards,

[Ge_Whiz]

Awesome indeed! Yes, I built the 'trimmerless' version as Tim described it in the thread you started recently. He obviously hasn't had time to update the diagram yet (something I can identify with!). The 'control' is incredible - unlike most distortion/fuzz controls which just give 'more of the same', this smoothly and gently completely changes the character of the sound as you crank it up - more like the 'morph' controls on some of the Digitech pedals, only better. Have you looked at the effect on a 'scope yet? I ain't seen nothing like it before.

At the moment, it's just a lash-up - it took me about twenty minutes to lay it out on a 2" x 1" piece of stripboard, and just over an hour to put the board together. Then I hooked it up to the sockets, pots and battery via a breadboard enclosure to try it out.

The only problem I've noticed is a lot of pot noise as I adjust the 10k gain control. I'm not sure if this is just a scratchy pot or if the circuit is sensitive to this. I'll fit out the final build with a decent plastic pot, and then see if it needs further help. If not, I can live with it for sounds like these!

Such a simple circuit, and it doesn't look as though the components are particularly critical either, other than perhaps the gain of the transistors. I used bog-standard 1N4148s for the diodes.

I've stated before that I like Tim's designs - mostly simple and elegant, but with interesting little design twists. I've built a few now, and every one has worked first-off. Of course, having the experience to lay them out on stripboard helps, but they're good circuits to practise with. I built the Phuncgnosis as a stop-gap before going on to the Nurse Quacky or even a full-feature clone, but it worked so well for me, I've just stopped with it while I play with other things.

[Mark Hammer]

I found that too- but it has a different designers name.

It's Tim's site, though you can't tell that from what shows up when you point your browser to that link.  Ever the nice guy, Tim credits his sources, and that's why it doesn't look like the right site at first.

[audioguy]

I see now... thanks Mark!
So no layout running around?

[jimbob]

I cant wait to give'r a try!

[Gary]

The only problem I've noticed is a lot of pot noise as I adjust the 10k gain control. I'm not sure if this is just a scratchy pot or if the circuit is sensitive to this. I'll fit out the final build with a decent plastic pot, and then see if it needs further help. If not, I can live with it for sounds like these!

That's the nature of that type of control.  It will be scratchy sounding.  There are ways you could change it, but it may have an effect on the sound, at the the very least it will add more components to the build.  I've seen this type of gain control before...

I haven't had a chance to look at the waveform, but your description certainly mirrors the sounds.

I'll guess that the only semi-critical thing is matching the NPN/PNP pair.  With different gains for these, you may notice some pretty good changes in the sound.  If you used sockets, you may try some deliberate mis-matching just for larfs.

Regards,

[puretube]

havent tried the circuit, but either a trimpot "north" or "south" instead of (or 1k trim added to) the 10k`s at the PNP/NPN pair might help adjusting mismatchings....

[Gringo]

I've drawn a pcb layout for the "trimpot version" and one for the "trimless" one. I'll assemble a pdf if there's interest.

[Ge_Whiz]

In my experience, 'complementary pairs' of transistors rarely match gain particularly well - PNPs are usually rather lower than NPNs, and that is true for my batches of BC549Bs and BC559Bs. In the end, I think I used an NPN of gain 370, and a PNP of 320 (subject to measurement errors, of course). When the circuit does its crazy tricks on a 'scope, everything seems to remain fairly symmetrical.


And now for our younger viewers, a word of encouragement:

Anyway, with yesterday's unexpected success still ringing in my ears, and my family about to drag me away from my soldering iron for another two weeks, I thought I'd throw together an unchallenging LoFoMoFo from the same site. So I cut a scrap of stripboard, dug out some old 100k resistors, three ceramic caps and carefully selected an ancient low-gain silicon transistor. I only had one capacitor left to solder in when I spotted an error - never mind, one resistor wire to move and a capacitor to desolder and shift shouldn't be too hard.

Of course, in attempting to desolder the resistor, I flipped the little circuit board onto the floor. I hate gravity at times like that. The workshop is pretty messy and full at the moment, so I had to lever myself off the stool and peer about for it for a while. No sign. Disappeared out of this Universe. And then I felt something under my heel...

Okay, don't panic. The transistor and capacitors have been folded down onto the board, but it's still good...straightened the transistor and a wire pulled out of the board, but don't panic, it's still good. Oh - the board is cracked through the copper strips, almost from side to side.

Well, my wife should be pleased - she's always asking me to throw some of the junk away...
:cry:  :x  :oops:  :?    :lol:

[audioguy]

I've drawn a pcb layout for the "trimpot version" and one for the "trimless" one. I'll assemble a pdf if there's interest.

Yes sir.. I am interested!

Thanks Gringo... it wouldnt be the same for me with out you around here!

Audio guy

[jimbob]

Im interested too. :lol:

[Marcos - Munky]

I have a layout for it in my site.

[b_rogers]

have any of you guys listened to the square wave shaper sound sample on Tims site?  kisten to the last 10 seconds or so...sounds kinda eric johnsony....nice creamy fuzz.


Brent

[Doug_H]

;lkj

[brian wenz]

Hello Hello--
   What about some other tranny choices for Q1??   Would a BS-170 work??   I'm assuming that Q1 should be higher gain then Q2 or Q3...
Thanks-
Brian.