New distortion from old parts

[brett]

Hi.  I quite like this thing, and thought I'd share it.  It's fairly simple: a bass fuss and a Big Muff style tone section.

The bazz fuss provides a heavy fuzz, with plenty of interesting overtones.  With the tone knob at "12 o'clock" the slightly modified Big Muff tone and gain section gives some mild scoop to the midrange.  It's subtle, but pleasing.  Turned up or down, the tone section can really lift and cut bass or treble.  

I think that anybody who likes a bazz fuss would LOVE this.


cheers

[B Tremblay]

The Bazz Fuss is a great circuit alone and a fun building block too.  The Whisker Biscuit at runoffgroove.com explores the same territory as your Wasp (great name), but with a Big Muff input section as well.

[petemoore]

If you have voltage measurements, they might help me to get it going.
 I kade the Darlingtransistor from pair of 2n5089's...actually a Darlingtransistor socket...and an NTE46,, have a MPSA13 around here somewhere...
 Anyway I'm trying to debug it, and wondered if you could provide for me some voltages to shoot for.

[brett]

Thanks Brian.  That Whisker Biscuit is very similar.  Dare I say - great minds think alike?  :wink:  
Pete, I think you'd be better making that Darlington out of two low to mid hFE transistors (e.g. 2N3904).  The 2N5089s will have hellish high hFE (like 500,000).  I *think* you could use a single 2N5089 in there, but the fuzz wouldn't be as heavy as with the Darlington.  Without measuring them, I think the Darlington should have about 1.4V on its base and 4V on the collector.  The other tranny will have a couple of volts on the emitter, and 0.7V more on its base.  The collector will be 3 to 6 V (you can't really get the second tranny wrong - it's a low gain configuration that is really more of a buffer than an amplifier).

cheers

[petemoore]

It needed to be wired right to work...
 Thanks, Brett, for the diagram, and getting the Pin voltages for me!!!
 Sounds pretty strong now with the 5089 in Q1, I'll have to do some more testing.. I just wanted to say I got it going! I think I hadda badda a diode. Changed that and it works.
 The two "Darlingtonized' 5089's 'work', more ragged note decay.
I thought I used High Gain/Low transistors for  building Darlington couples before with good results.  
 I have the "double-darling-socket', I can try some different type Q pairs in that and see what I can get going that I like  for Q1.
 I'ts just an 8pic IC socket, a column for each transistor, I'm jumping the diode across to the input caps extra socket pin :wink: , from the transistors 'extra' collector socket.  Using a small piece of perf for the socket only, and medium core [diode clippings?] wire making the darlington pair connections, with the wires trimmed to go into the transistor socket. I can plug in different Q1's a and b and different diodes !!

[brett]

Hi Pete
Damn clever those 8 pin sockets for Darlingtons and piggybacking.  Too cool by far  

[petemoore]

This Wasp thing is a good time, I was down there testing it, in the dungeon for quite a time !!!
 Explosive Low Notes...
 Really cool backoff guitar vol [gain] sound, was 'window washing' [up and down strokes from elbow] at about 7, then turn the volume for real thick gain roll on effect, and extreme thick distortion chords [no high strings needed on bar chords...] Bouncy Drive Punch Crunch on the Bass...is just too funny...Blue Cheer !!!
 Oh I found the MPSA13, much more in that than the NTE47 I was trying it with before, and that made it cool too, quite a bit different, Lower Gain by a good amount, still real fuzzy, and had a really cool rolloff...I'll have to go back and try that again, it was PDG too, had lots of character.
 Really cool Fuzz...Tons of output,
 Thank you for sharing your findings Brett.
 One of these circuits 'round here is getting kicked out of it's Raco...This one works too good.

[brett]

Thanks heaps Pete.

I forgot to mention in the original post that an MPSA14 has higher hFE (well, higher minimum anyway) than an MPSA13, and sometimes I think it gives some different tones in the WASP.  Hard to tell for sure with subtle stuff like that some times, but maybe worth a go.

have fun

[brett]

And just for reference, here's the theoretical frequency response of the WASP with the tone knob at 12 o'clock.  (Thanks Duncan for the Tonestack calculator).
Sorry about the lack of scale, but you'll get the idea anyway.  The scoop is deepest from 500 hz to 1kHz.  (ie from middle A (the one on the G string) upwards for an octave and a bit)

[petemoore]

Yupp, hard to tell subtleties in a circuit, subtleties are certainly not what this circuit is about, expecially with the guitar up.

[petemoore]

With the buffer in front, and a retuning [glossy red input cap marked 505, and the NTE47 transistor], its really excellent, amazing twangy bite!!! What a character !!!