One Knob Fuzz goes Hexaphonic!

[marionett]

I had some free time in August and was looking for a simple DIY-Project to keep my brain occupied. I then stumbled across a Roland GK-2A hexaphonic pickup (for free) and was wondering what I could do with it, without buying Guitar-to-Midi-Gear.
I ended up building a hexaphonic One-Knob-Fuzz and am quite fascinated by the possibilities polyphonic distortion offers.
Sorry for the messy layout, it's still a prototype, and underwent a few changes while building (had some problems with the output impedance of the hex-pickup and the power supply for the pickup (+7V and -7V) - also it is my first (working) stompbox project(without the "stomp"-part, I use an A/B-Box to switch between my normal guitar chain and the GK plus Hexfuzz.)
I used D-Sub-Connectors - those round 13-Pin-Roland-Connectors are a pain in the ass to solder (and a stock GK-cable is about 50 Euros, so I had to build my own).
For the recording I used a cheap Danelectro Equalizer and went into a  Boss Me70 (Tweed-Setting). Nothing fancy, just an example how a hexfuzz sounds (especially in terms of harmony and dissonances).  I did include a tonecontrol (as seen in one of the pictures) at first, but it sucked too much volume and I didn't want to build a recovery stage, so the danelectro equalizer has to do it for now.



Sounds:
First some chords of varying complexity in different positions, then a demonstration of the intervalls from octave to prime and their "resolution", then some natural harmonics, no music and no real playing, for music you have to listen to me elsewhere
http://www49.zippyshare.com/v/79235403/file.html


(PS: English is not my first language, so be kind )

[Elijah-Baley]

Bravo, marionett!
Very interesting sound!
I was looking for something like that, or something octave up and down effect on veroboard.

Schematic? 

[duck_arse]

mmmmmm, kiwifruit ......

[stm]

Very cool!  Great demo playing all these complex chords and intervals.

[Mark Hammer]

When he was in town for a year, and away from his family for extended periods, Japanese synth whiz Sam (Osamu) Hoshuyama made hmself a "lunchbox synth" that still humbles.  Looks like you were taking some lessons from him! 

[mth5044]

That's such a unique sound, great job!

[electrip]

Sounds a little bit like baroque harpsicord playing. :-)

electrip

[marionett]

Those IKEA-lunchboxes are quite cheap (actually it was free, it belonged to my girlfriend ) and I don't have an electric drill at home, so I needed something I could poke holes in some other way (a needle attached to my soldering iron did the trick ).
And yes, the sound is quite unique. I'm still figuring out what I can do with it. Chords are much clearer but it is very sensitive to unwanted string noise and resonating strings.
I play a lot of classical guitar and I would love to incorperate more fingerstyle into my electric guitar playing, hexafuzz/distortion might finally be the way to do so.

Next step would be a gain knob. Is there an elegant solution for that purpose? I have to control six resistors with one knob and a sixfold-potentiometer is quite clumsy(and unobtainable and probably huge?).
I thought of a LDR/LED-combination, but there might be better ways?

[samhay]

Sounds great - fuzz without so much IMD.

Is this the one-knob fuzz design you used?
http://www.beavisaudio.com/schematics/Colorsound-One-Knob-Fuzz-Schematic.htm

I take it you mixed the 6 outputs together with those resistors shown on the breadboard before the volume pot?

[Elijah-Baley]

Those IKEA-lunchboxes are quite cheap

I thinking about something similar and put in my smokey amp. Or some else plastic box. I'm looking for something cool.

[marionett]

Yes, Samhay, that's the circuit, quite simple yet effective and well sounding.
I used 100Ohm for R2 (shouldn't make a real difference) and BC549Cs for Q1 and BC550Cs for Q2.
And yes, I mixed the outputs with resistors before the volume pot (I ended up with 47k resistors).
I still have a noticeable drop in volume (compared to my normal guitar signal) and I'm using the Danelectro EQ to counteract that. It does work, but is far from optimal.
Maybe I have to try some other values for the mixing resistors, or I just have to add an active booster (this would sort out the problem with the tonecontrol-volume-drop, too).
For the next modification I would love to have a tone control, active volume control (if necessary) and the former mentioned gain knob. But I have to do some thinking, before I order new parts...
(I was thinking of a more modular layout for further experimentation, with breakout-box for digital processing via computer and a signal splitter to do some more processing (envelope filter for each string would be crazy). But it's not the time for megalomania, still: lots of ideas but not enough free time to solder musical gear AND play it sufficiently  )

[Elijah-Baley]

Yes, Samhay, that's the circuit, quite simple yet effective and well sounding.
[...] I mixed the outputs with resistors before the volume pot (I ended up with 47k resistors).

I'm a little newbie. Could you explain what does it means?  Schematic?

Thank you! 

[helloesposito]

Sounds dreamy!