Finally got around to a Superfuzz.

[digi2t]

If you wanted to go stark raving nuts, then what you do is replace a 22k/10k resistor pair with a 20k pot, wiper to the 100nf cap, and a 5k1 on either side of it, to move the rolloff of the LPF part around.  That, in conjunction with the variable bleed-to-ground through the 100nf cap will gve you plenty of tonal variation, though maybe more "tweak maintenance" than one normally wants in a stompbox fuzz.

Naw, it's nuts enough for me. I'm boxing it as is. It's met the "Smile Factor", which is to say, after 1 hour of noodling and twisting the dials, I'm very happy with it.

Many thanks for your everyone's input, and thanks Mark for the filtering math. I'm stickin' a fork in this sucker.

[digi2t]

Finally boxed. Probably the last build before the move, which sucks because I have the Schumann PLL board ready to populate.

Anyway, I named it in honor of my bro Jimi. Magic marker? Hell Ya!









Those Sylvania 1N450 diodes that I picked up from Electronics Goldmine look really rad in there. I think I took that cue from Lucifer's Trip Turkey Day fuzz. They look like a pair of nuclear reactors in there.

Here's a video of it in action. Mark, I got that sitar sound you were talking about.

Don't know what took me so long to build one. Me likey.

[Brossman]

Hey man, great build! Been meaning to get around to one of these for a while myself, though I'll likely go discrete, as that's most of what I have (erm, rather, what I gut...)

Cheers for face-melting, splatty fuzz!

[digi2t]

Hey man, great build! Been meaning to get around to one of these for a while myself, though I'll likely go discrete, as that's most of what I have (erm, rather, what I gut...)

Cheers for face-melting, splatty fuzz!

This is discrete. You can use the same vero. The TPQ2222 is just four 2N2222 transistors, in one package. If you use individual transistors, just plug them into the same EBC spots on the vero.

Here are the updated veros. Three versions, using different octave sections. Again, you can use regular transistors as well. Just use the EBC pinouts on the board.







The only difference is that I made more room for the diodes, added the scoop control, added trimmers for Q6 collector voltage, and diode ground lifting, and I added a 100uF cap for filtering.

[pinkjimiphoton]

dood!!1 i am honored and it sounds great!!

[digi2t]

Update:

I've been scouring the net for other possible "dual NPN" transistor packages in the octave section, and having ordered a few, one showed up today. The 2N2913. I had to add another SIP socket, since it has an extra leg over the 2SC1583 (separate emitter legs). Here it is plugged in;



Using the tone generator at 200Hz, with the drive at minimum, I readjusted the octave section trimmer to achieve max octave output by ear.

This puppy really puts out a much purer octave. With the drive at minimum, anything over the 10th fret really pops. Way more than the 2SC1583. Even tuning it by ear with the generator, it was easier to hear the octave jump out at me than with the 2SB1583. Checking the gains with my Peak meter, one half comes in at 178, while the other shows 180. Lower gain than the 2SC1583.

In the end, if you're looking for more octave sing than the 2SB1583 can provide, you might like to try this package. It gets my two thumbs up, and has now replaced the 2SC1583.

When some of the other duallies come in, I'll try them, and report back.

[Mark Hammer]

So how much of this would be accomplished by matching a pair for hfe and glueing them together for sharing thermal characteristics?

[digi2t]

So how much of this would be accomplished by matching a pair for hfe and glueing them together for sharing thermal characteristics?

Would probably deliver the same, or better depending on the pair (and glue), performance.

Although it would just eliminate the child-like anticipation of me waiting for these goodies to arrive. 

That can does look a bit "mojo-tastic" though, don't it? Come on Mark.... 'fess up! 

[Mark Hammer]

As Rompin' Ronnie Hawkins once said "I'm that mojo man".

[kingswayguitar]

  
i'm lovin this thread right now

[digi2t]

As Rompin' Ronnie Hawkins once said "I'm that mojo man".

Ah yes... the late great Ronnie Hawkins. I used to love watching his show on TV, and especially the interview he gave once, talking about purchasing his Rolls Royce.

Salesman - "Excuse me Sir, but do you know what those two R's stand for?"

Hawkins - "Sure I do! They stand for "Rock and Roll". I'll take that one."

A legend.

[Mark Hammer]

Um, if he's "late" it'll be because his alarm didn't go off, and not because he's six feet under.  As far as anyone knows, the Arkansas gentleman is alive and well and growing his beard in southern Ontario.

[digi2t]

Um, if he's "late" it'll be because his alarm didn't go off, and not because he's six feet under.  As far as anyone knows, the Arkansas gentleman is alive and well and growing his beard in southern Ontario.

Did I write "late great"? Damn! Just blew a major brain fart there. Probably because I was reading the Jeff Hanneman articles just before I checked in here. Don't ask me about the connection, I couldn't tell you. I think the brain was subliminally in "death mode" when you brought up Ronnie. No, Ronnie is still around, in Peterborough, I think. I better correct my previous post. Or maybe leave it... to teach me a lesson!

Damn... I've got to stop and think, before I go writing $hit down sometimes. I end up killing people otherwise.

[Ofek Deitch]

What's the difference between these layouts? (Except for jumper between the Collectors of Q4 and Q5 that moves one spot to left)

[digi2t]

Other than the jumper noted, nothing.

[UKToecutter]

Is anybody interested in a PCB if I do a small run?

[pinkjimiphoton]

oh lawds yes.
how much?
pm imminent!!

[duck_arse]

this thread is older than I thort.

that diode lifting looks dangerous. so much signal! I haven't had a listen to one yet. and un/mis/matching for the rectifiers is producing some unexpected results, too.

a note for anyone else playing with an octave lift: lifting the feed from the emitter produces a vastly different signal to that from lifting the collector signal. the collector when overloaded clips the signal, then cuts half and shoots off pointy ugly distortion, best described on an oscilloscope screen. the emitter feed looks like the follower it is, and produces a cleaner signal (which will still clip).

some might like that horrible distorted signal further mangled with the diodes, others might prefer the cleaner feed. I discovered the hard way, I coulda just searched to find this:

http://www.diystompboxes.com/smfforum/index.php?topic=93154.msg799839#msg799839

[digi2t]

I didn't go for the complete diode lift, it's just too much for me. A trimmer to adjust to something more preferable than "full on" or "full off" is OK. I have mine lifted just a bit from ground, enough to make it a touch raunchier. I guess I could have saved the trimmer for another project by sticking an equivalent resistor in there, but if I get bored, it's there. 

What was your final approach to the octave lift dilemma?

[Mark Hammer]

My solution to the volume difference between diode clipping and diode lift is to stick a resistor in series with the Volume/Balance pot, and use a DPDT toggle for the diodes/no-diodes switching.

With a 47k fixed resistor in series with the pot input, the amplitude is always chopped by at least half (47k/50k).  When the diodes are tied to ground, you use the other set of toggle contacts to bridge the added resistor, restoring normal function.  When the diode contact to ground is broken, the toggle UN-bridges the added resistor, dropping the amplitude to compensate for the added volume when the diodes aren't there to impose a ceiling.

Simple strategy and works great.  The value of the added resistor is up to you, but 47k is a good place to start.