Least transparent circuit possible...

[rockgardenlove]

How might you go about creating the least transparent effect possible?  Something that would eliminate dynamics, equalization, texture, etc. as much as possible.  Basically what could you do to make a guitar signal sound as much like a simple oscillator as possible...?

Just wondering.

[Quackzed]

A)easy, just remove the chord going from your guitar to your amp.
it totally changes all the tone and dynamics and eq and texture and whatever else.
totally!
TOTALLY!!!
B)guitar sound like a simple oscillator?? throw it up in the air really high!

[Quackzed]

ahh sorry mate, just having a little fun with you there...couldn't resist 

[aziltz]

A really really bad fuzz (bad meaning nasty sounding), then run a really effective low pass filter.

[Paul Perry (Frostwave)]

If monophonic is acceptable, then a low pass filter followed by a compresor might be the go. The low pass filter will take off the harmonics, and the compressor will take off the dynamics.
For a high -tech approach, you wnat a tracking filter... but that requires either a DSP approach or else the usual hardware pitch extraction problems, then the tracing filter.Or you could go with a phase locked loop, but you usually get artifacts as it locks in.

[MartyMart]

Psychtar is a fairly "wacked out" fuzzy/sitar thing, that is a lot of fun to play around with
Stick it through some chorus/delay for very "synth" sounding drones !
MM

[syndromet]

A truebypass looper through a Fuzz and a wha. Pure oscilation, with the pitch controlled by the wah.

[Jeremy]

You can send the guitar signal to a shallow-sloped low-pass filter and then a comparator circuit, that turns it right into a rectangle wave. 

If you do this, you might as well be playing a synth set to square wave.  Dynamics, EQ, texture, nuance...  It's all gone.  Only pitch remains, and at that, probably only if you'll play one note at a time.  Play more than one note at a time, and I think it will give you some weird pitches at the output (intermodulation).

:::added later:::

The bonus is that this is a really simple circuit.  One way to do it (although maybe not the best way) is just to run the signal through an op amp without any feedback at all. 

Just bias your input signal to 4.5 volts [assuming 9V power supply] and send a 4.5 volts reference voltage to one of the op amp's inputs, and send the biased signal to the other input.  The output should be a really huge rectangle wave.  Put a blocking cap and a volume control at the end.

[slacker]

I'd try some of Tim Escobedo's circuits

The uglyface, PWM and simple squarewave shaper do pretty much what you want in a dirty way which I guess you could then clean up with filters.
I've only built the uglyface but that has absolutely no dynamics, it's either on or off, unless it's self oscillating in which case it's on all the time If you filter it heavily before and after to remove a lot of the harmonics it sounds pretty synthy.

[H S]

You can send the guitar signal to a shallow-sloped low-pass filter and then a comparator circuit, that turns it right into a rectangle wave. 

If you do this, you might as well be playing a synth set to square wave.  Dynamics, EQ, texture, nuance...  It's all gone.  Only pitch remains, and at that, probably only if you'll play one note at a time.  Play more than one note at a time, and I think it will give you some weird pitches at the output (intermodulation).

More specifically, what remains is the location of the zero crossings.  Pitch information remains, but a good deal of timbre information is still in there, too, basically in the form of "pulse width."  Changes in pickup location and picking location will still effect the output.

[smnm]

my clips of Tim E's PWM & Uglyface -

http://www.geocities.com/thesimonmurphy/sounds/pwm_1.mp3
http://www.geocities.com/thesimonmurphy/sounds/uglyface_1.mp3

S

[Ge_Whiz]

...or the Crash Sync. Much the same thing as Tim's.