Getting prepared for DT project, using the SquareWave Fuzz

[dyrodium]

I really like the sound to this effect 

So far i've got all the resistors (couldn't find a 2M though, so i'll wire two 1M's in series) and caps, but couldn't find the diode 1N34A anywhere, nor the 2N5458 JFET, but I believe the 2N5008 NPN transistor is fairly common so i should get it when i have the time to search for it properly.
I'm in sydney, Australia, does anyone know a place here or and aussie net store where i could find these parts? I really want to make this pedal as said before... 

Another Question regarding the casing, for RF blocking it needs to be metal, but would it matter what metal? I'm planning on welding up a steel box for that industrial touch. Anything else I should know about the veroboard layout or this effect in general that I should know before starting?
Thanks in advance.
Angus

[pyrop]

Hi Angus
Well I dont think you are going to get a 2N5458 or a 1N34A (or nearly any other GE diodes) in OZ.
For the 2N5458 try a MPF102 (avail at jaycar http://www1.jaycar.com.au)
For the 1N34A try a 1N914/1N4148.
I'm not familiar with the circuit you are building so I can't tell you what using a 1N914/1N4148 will change although in most cases it will give you a higher output.

pyrop

[dyrodium]

Cheers! Turns out the 1N34A IS a Gemanium diode, thanks for the heads up...  Hmm that will be hard to find...
Although I did find an ebay listing, so may get that, but I want two, not 10 lol. It's the 1N60, apparently a direct replacement for the 1N34A.
I'll get the replacements you suggested and give them a go!

[pyrop]

I got some 1N34A's from Futurlec.com.au @ 66c for 10.
Note there are risks using futurlec as they come from Thailand although I have had no dramas. Search the forum for futurlec.
BTW if you are going to building more of there stompboxes you are gunna need more than 10!
And those ones on Ebay $5.30us plus post is way to much.
Aron sells them in his store (click store above) @ 8 for $2us.

pyrop

[dyrodium]

Yeah true, I think i'll make a futerlec order, and aron's store is really good i've checked it out, but I have a thing with ordering from overseas... i've already got $300 worth of gear arriving by surface from the states... 

[Mark Hammer]

The Squarewave actually distorts nicely even without diodes.  Mine has a 3-way switch for Si/Ge/none.

It's not completely unappealing, but I didn't find that the unit thrilled me.

I'm guessing the drive/gain of the FET (the SW has a fixed drive setting) can be adjusted by installing a variable resistor (let's say 5k-10k) between the + side of the 33uf cap and the 3k9 resistor.  Also, consider other bypass caps for the tone control instead of the .001uf stock value.  Another thing to consider is running a .1uf cap to ground from the junction of the 250k pot and the 27k resistor.  That should get you some nifty midscoop sounds.

[dyrodium]

Cool! I'll make it without the diodes for now then, and try the mods you suggested. 

[jmusser]

Are you making a squarewave fuzz to use with something else (DT?)? Which Squarewave Fuzz are you building?

[dyrodium]

I'm making a stomp box for my design tech project at school, and thought I'd use the squarewave fuzz circuit for it, I'm using the veroboard layout fpund in the dragonfly album. Is there a similer effect with those nice overtones I should try instead? Also, not actualy being able to play guitar (for shame eh?) It's partly for my dad and for some experiments with altered piano sounds (rout the mic through the pedal). I also figured it's a great way to further enhance my electronics knowledge! 

[jmusser]

From the looks of it, Dragonfly has the Univox Square Wave Fuzz on his site. That one is a fairly whimpy representative of the square wave tone in my opinion. I have built 4 of them, and by far the best sounding one has been Tim Escobedo's "Simple Square Wave Shaper". It also has adjustments which take the wave form from that to sawtooth, and a sort of trapazoidal wave form. Both are very cool tones. The square wave tone on here is the intense synthy tone that most people think of when they think of square wave. Tim also has another circuit over there that is called something like "Octup Blender". That is an awesome circuit that has an intense squarewave, and octave up, that you can blend into a boosted fundamental guitar tone. It's one of my very favorites, and closet circuit that not too man have built. Lastly, there is a "Triggered Square Wave" circuit on Casey's site. I believe it also goes by "Optimum Fuzz". It's a vintage circuit from the late 60s, and sounds real good too. If you go to search, you'll find a Circuit build report I've done on all 3 of them. Let me know what you decide, and if you need help, PM me anytime.

[Mark Hammer]

The Univox Square Wave Fuzz is simply the name of the unit, not a description of what it achieves.

[jmusser]

I just naturally assumed that when it said "Square Wave Fuzz" that is what they were trying to achieve.    Since I didn't know what the wave form looked like that came out of it, I figured they just didn't achieve the tone they were going after. It never did sound like a square wave tone, but more of a mild and warm sounding distortion. After I built Gez's Square Head, and it didn't have a very defined square wave tone either, I thought maybe I was just missing something and there were subtle shades of square wave. OK then Mark, what is the "real" story on the Univox circuit ?

[Mark Hammer]

I don't have any "real story" on it.  I will simply note that it is a 2nd cousin twice removed of a Fuzz Face, with a FET where Q2 ought to be, and with some Bosstone in its genetic inheritance (post Q2 diodes).  At the time it came out, Univox produced a flurry of pedals to complete a "line" (I had one of their compressors in the 70's from that same product line).  They went for something a little different, and it wasn't particularly compelling.  It's chief distinguishing feature was the replacement of a Fuzz control with a Tone control (keep in mind how many distortion pedals until 1980 were 2-knobbers: Fuzz + Volume) that rolled off the bass for buzzier sounds.

[dyrodium]

Hmm interesting... so what effects could I build that does have square wave "tube" qualities? I could have sworn that sample of the effect had some, maybe not.

[Mark Hammer]

Well they ALL provide *some* squaring, because that's what clipping will do, but if you want something that provides a square-looking output from the beginning of the note to its last dying gasps, you need a different sort of circuit.  This is typically some sort of Schmidt-trigger based device that compares the input to a reference, and turns the op-amp up full tilt when the input is greater than the reference, and off when the input is less than the reference.  The "Ultra-Fuzz" project from Craig Anderton's EPFM-II did this.  The schematic has to be around somewhere.  My guess is that something over at Tim Escobedo's site also does this.