Using Octaver/Blue Box-type circuitry for true guitar synth?

[Rodgre]

There is always talk about building guitar synthesizers and how complicated they can be to do well. At the same time, there are several octave divider circuits, both commercial and available as schematics/projects online, which track pretty well as they are. Can these circuits be modified to put out a sound that is a different interval/octave than the usual one or two octaves down?

I recall seeing mods in Craig Anderton's Electronic Projects for Guitarists book for his Rocktave circuit, which would give you different intervals, but I don't recall ever seeing mention of using octave divider circuitry to give you the SAME interval, only a synthesized tone.

I realize that it's often easier to use the actual guitar signal, fuzz it up and then run it through synthesizer-style CV filters, CV amplifiers/envelope modifiers, etc, but the thought of having an albeit sometimes glitchy (in a fun way!) signal that can be converted to different waveforms simultaneously to create new sounds.

I know that I've done tracks in the studio where I have used an octaver to shift the guitar down an octave and then used both a digital pitch shifter and a more traditional octafuzz like a Tone Machine to shift it back up to the original octave. There must be a simple way to combine this sort of effect into one circuit, no?

I'm sure I'm asking about things that have been covered a million times in the guitar synth threads, but I'm just looking for an answer to one question: Can an octave divider circuit be easily modified to put out a synthesized tone the same octave as the input?

Roger

P.S. I just realized that this post sounds an awful lot like one of Carrie's philosophical columns in a Sex in the City episode. I know this because my girlfriend makes me watch one episode of SITC for every episode of "Classic Albums" or "Myth Busters" that I watch in order to keep our relationship balanced.

[e45tg4t3]

hello...
you may can use this:

connect the input of it to the first octave down output of the bluebox and connect the 2x junction in the schematic and leave the others open...
then you should have the same octave than the guitarsignal just synthesized... try it and if it works please post a little reply^^

Benny

[Stellan]

P.S. I just realized that this post sounds an awful lot like one of Carrie's philosophical columns in a Sex in the City episode. I know this because my girlfriend makes me watch one episode of SITC for every episode of "Classic Albums" or "Myth Busters" that I watch in order to keep our relationship balanced.

OMG Poor you. I volounteerly (sp?) watched the movie with my GF on her birthday. It was painfull... Probably the biggest act of love i ever did was sitting through the whole thing without complaining

[caress]

isn't that more or less what the uglyface is?  minus the envelope filter...

[Rodgre]

isn't that more or less what the uglyface is?  minus the envelope filter...

That's an interesting question. I assumed that the synthesized note on the Uglyface was arbitrarily swept with the envelope control, and unable to latch onto the note that you were playing. That is to say that I pictured the Uglyface as a heavy fuzz with a simultaneously oscillating oscillator which has it's pitch swept from high to low with the envelope of the input signal triggering the sweep.

In that situation, if the sensitivity is set so there is no sweep, you have a static oscillator note, not one that follows the pitch of the input.

I'll check that circuit, Benny. Thanks for the tip.

Roger

[caress]

isn't that more or less what the uglyface is?  minus the envelope filter...

That's an interesting question. I assumed that the synthesized note on the Uglyface was arbitrarily swept with the envelope control, and unable to latch onto the note that you were playing. That is to say that I pictured the Uglyface as a heavy fuzz with a simultaneously oscillating oscillator which has it's pitch swept from high to low with the envelope of the input signal triggering the sweep.

In that situation, if the sensitivity is set so there is no sweep, you have a static oscillator note, not one that follows the pitch of the input.

ahhh right you are...

[ambulancevoice]

P.S. I just realized that this post sounds an awful lot like one of Carrie's philosophical columns in a Sex in the City episode. I know this because my girlfriend makes me watch one episode of SITC for every episode of "Classic Albums" or "Myth Busters" that I watch in order to keep our relationship balanced.

OMG Poor you. I volounteerly (sp?) watched the movie with my GF on her birthday. It was painfull... Probably the biggest act of love i ever did was sitting through the whole thing without complaining

im surprised you made it out alive

[kato]

I was just wondering something similar....

Could I somehow remove the fuzz effect and get just the octave down? Would probably sound cool and synthy.

But I don't know much about modifying boxes. Can I just remove the fuzz diodes?
Or is it altogether more complicated than that?

Thanks for any advice,  Kato

[Radamus]

I don't want to sound pushy, I know you guys are busy, but did anyone try this idea out? I'm curious what the result was like. I've been dying for some interesting synth tones without resorting to digital.

I'd be willing to try putting some of these ideas together, but I'll need careful instructions.

Thanks.

[Processaurus]

Somebody made a PCB of the fundamental extractor from the Boss OC-2 around here.  That is a good way to go for a more synthesizer-like tone, because of how it works it puts out an even duty cycle square wave, where as other synth like effects I've tried sound like really heavy fuzz.

[StephenGiles]

Every couple of weeks this topic jumps up, you cannot hope to have even a half decent tracking oscillator without a fundamental extractor. I spent a great deal of time between marriages experimenting with anything I could find on this, and until the EH Rack Guitar Synth came along which, as you will know, contains a very good fundamental extractor, nothing was usable.

I would estimate that the circuitry is the equivalent of maybe a dozen Rats, not difficult to build - it helps to be on your own, or have a wife/girlfriend with a time consuming hobby!!

[Processaurus]

Good guitar synthesis is pretty elusive, I agree.  But the original post is asking for bad synthesis, no?  Which can be a lot of fun (I'm sure your EH clone is raging fun, too, though).
The line 6 purple modeler pedal has good "bad" synthesis. That one is great.  I like Tim Escobedo's PWM as well, the uglyface too.  Once you have a logic level signal, you can mangle it with logic gates to sound different/more animated.  A fantastic, worthwhile mod to the Blue Box I've done is to insert the logic section of the PWM (the schmitt trigger section after the 386) in the fundamental square wave's path, in between Q1 and R11 on the tonepad schematic.

Oh yeah, there is Ray Wilson's mono guitar synth project too, if you're interested in bad synthesis with more bells and whistles.
http://musicfromouterspace.com/analogsynth/GUITARSYNTHAUG2007/GUITARSYNTHAUG2007.html