How do I add octave down to a fuzz?

[Absentidei]

I'm building a silicone fuzz-face like device with gain control for each transistor, a simple switchable octave up using a transformer and two diodes, a bigg muff tone controller and a feed back loop that goes from the output just before the volume pot and is controlled by a 1m linear pot and a SPST momentary foot switch to engage it.

Would it be possible to add an octave down to this mess somewhere?

Is there any pedal with an octave down function where I can grab the "octave down" module and add to my current schematic?
I was thinking to use a 2p3t rotary switch to change between normal, octave down and octave up.

Another thing I'm wondering about. When my guitar is plugged directly into this pedal and the feedback switch is closed, it interacs VERY nicely with my guitars's volume and tone control.
When I plug a buffered pedal before it, it just kinda goes into a high pitched whine. Is there some way I can change that? I don't expect it to be able to interact with my guitar if anything is in the signal path before it, but I'd like it to sound a bit more natural.

[pingjockey]

i dont know, but i would love to see the schematic when you have it all down. nice idea. 

[LucifersTrip]

here's one...



http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=44125&g2_serialNumber=2

[Absentidei]

Yeah, I found that, but didn't quite get what made the octave down.

Is it the diodes from collector to base?

[R.G.]

I'm building a silicone fuzz-face like device with gain control for each transistor, a simple switchable octave up using a transformer and two diodes, a bigg muff tone controller and a feed back loop that goes from the output just before the volume pot and is controlled by a 1m linear pot and a SPST momentary foot switch to engage it.

Would it be possible to add an octave down to this mess somewhere?

Yes. The question is where you can find a clean signal to octave down. Generally you want a undistorted and gently low-pass filtered signal to give to the octave down. Analog octave downs square up their input signal and then run it into what amounts to a digital flipflop, which divides the frequency by two, and then filter the result a bit to clean it up from the digitalness.

Is there any pedal with an octave down function where I can grab the "octave down" module and add to my current schematic?

It will amount to building the other pedal into the same box. Look at the Blue Box or Roctave divider.

[Absentidei]

Ah. That's a bit more work than it's worth in this case I think.

I was hoping there would be some simple-ish module that I could just plug straight into my current layout, like I did with the transformer and two diodes for octave up.

Both those effects seemed a bit more complex than I'm comfortable with.

[pingjockey]

I'm guessing you lose some noticeable gain in the signal with the octave down.  That right?

[rollo greb]

Maybe look at the shocktave? Everything after the 2 transistor gain stage is what makes up the octave down section I believe. If you look up a circuit called the downbox it should make sense, that is basically the shocktave with the gain section replaced with a bazz fuss.

I've built the shocktave and while its not perfect, it gets a good octave down if you play around the twelfth fret with the neck pickup. Anywhere else on the fretboard tends to get a bit glitchy.

[gcme93]

Maybe look at the shocktave? Everything after the 2 transistor gain stage is what makes up the octave down section I believe. If you look up a circuit called the downbox it should make sense, that is basically the shocktave with the gain section replaced with a bazz fuss.

I've built the shocktave and while its not perfect, it gets a good octave down if you play around the twelfth fret with the neck pickup. Anywhere else on the fretboard tends to get a bit glitchy.

I find the best clean octave down effect if you're playing at 12th fret is the "playing down 12 frets" effect. Hardly any glitchyness

[Mark Hammer]

I'd like to know how some fuzzes that do not have any sort of flip-flop built in can occasionally get octave-down sounds.  For example, we've seen that some very minor changes to the Jordan Bosstone, and the Harmonic Percolator, can often generate octave-down sounds if you pick right, and I have no idea how that comes about.

[R.G.]

I'd like to know how some fuzzes that do not have any sort of flip-flop built in can occasionally get octave-down sounds.  For example, we've seen that some very minor changes to the Jordan Bosstone, and the Harmonic Percolator, can often generate octave-down sounds if you pick right, and I have no idea how that comes about.

Intermodulation distortion.

Intermod generates the sum and difference of frequencies sent into the distortion process. Sometimes with some combinations of notes, the difference frequency can be at or near 1/2 of one of the input frequencies.

This effect is heavily dependent on the type of distortion and the original frequencies sent through it. All distortion processes generate both harmonic and intermodulation distortion to some degree.

[Mark Hammer]

Which would explain why the octave-down on these things is so elusive.  If it depends on the dufference  (or sum) being "just right", you're not going to hear it all the time.

[R.G.]

Yep. I think the human hearing mechanism may search for and find octaves and highlight them to the higher supervisory-sensory levels.