Superfuzz / Ibanez Micafuzz octave cut

[tomtom]

I have an old Micafuzz (one of the hundreds of clone or modified Superfuzz) and it's quite nice for bass, nasty with big bottom.
I would like to play better because I made too much noise or not enough
string muting on faster parts so it's a mess soundwise because of the octave effect.
I wonder if it's possible to kill the octave effect. Some diode rectification octavia use to put one diode out to kill the octave. Does it work alike with one of the transistors on the differential pair ?

I was thinking about using a pot where a 470R/1K resistor go to the lower transistor off the pair.

Thanks.

[Mark Hammer]

If it's a Superfuzz clone then cancelling the octave effect is relatively easily done.

Most transistor-based octave-up fuzzes use a single-transistor phase splitter.  This is a transistor identified by identical-value resistors between V+ and the collector, and between the emitter and ground.  Values of 10k are especially common.  So, if you find a transistor on the board that has emitter and collector resistors of around 10k (e.g., 8k2 in the Fender Blender), and no capacitor going to ground from the emitter, THAT'S your target.

The phase splitter will have opposite phase versions of the signal presented at the collector and emitter pins.  In some instances, these are fed through diodes to chop off one half-cycle of the signal.  When they are eventually combined, they produce an output where the waveform looks like it is "folded over", such that the troughs in what would have been the original signal are now also peaks to go along with the existing peaks.

If you simply lift the connection to *either* the emitter OR collector of that transistor, you should get a non-octave fuzz sound.  Note that I say this without any schematic in front of me, but based on what I've seen elsewhere.  

It is an easy-enough mod to do.  Just identify the key transistor, identify the E and C pins, decide which one is easier to get at, and desolder/lift one side of whatever component on the board  (usually a medium value electrolytic cap such as 4u7 or 10u) is tied to that pin.  Just make sure to leave the two equal value resistors in place.

[Dan N]

Something else you could try, you know how some superfuzzes have a trim pot to dial in the best octave? You could add a pot to dial it out. Or back in. Or out...

The bases of the transistors in the differential pair go through 22K resistors to ground. Lift those resistors and hook them to opposite sides of a 10K pot. Connect the wiper to ground.

Remember, the transistors are ECB pinout. There are only 2 22K resistors touching ground in that circuit, so you should be able to sniff them out.

Ummm, that's my favorite superfuzz type circuit. Just a crazy fuzz!

[petemoore]

Which one??? <!>
 Is there a schematic available for the clazie SuperFuzz you mentioned, Dan N.?

[cd]

Look in the schematics section at the link on the top of this page.

http://www.geofex.com/FX_images/univox1.gif

[petemoore]

WOW
 Sort of a 'Whopper!"

[tomtom]

Thanks Mark, I have to try it, I was thinking about removing wire after the electrolytic, I will try.

By the way, I love both Ge and Si clipping (diodes).
Do you know a way to blend the two, or blend between non clipped/Ge/Si? I was thinking about a 1k wiper to circuit and each diode pair at each end of the pot...

[Dan N]

Hi petemoore,

Here's the Ibanez variation of the circuit. Just a tad wilder than the normal superfuzz.

http://members.fortunecity.com/uzzfay/iswf/iswfsch.html

(watch out for pop-ups)


clazie? Nice Thai accent!

[cd]

(watch out for pop-ups)

Use Mozilla, Firefox, Opera, Safari if you're on OS X, etc. (anything except IE and Netscape), they've got built in pop-up blockers.

[travissk]

For IE users, try the Google toolbar - popup blocking, google searching, button to go to Google news, no spyware... good stuff

http://toolbar.google.com/

Of course you can always "upgrade" to Firefox too