Is there a simple octave up and octave down in one pedal?

[Ben Lyman]

Very cool Duck, thanks! I will mess around with that. It's funny that you posted just now because I too am back at this after giving my brain and ears some time off.

I revisited it last night and came up with this, it's starting to get a little bit insane with the 5 knobs and stuff but lots of great sounds.

I now have 3x 10K hanging off the buffer (r2, r28, r31) and I wanted to check with you all to see if it's okay what I've done here.

The new one is a dry signal going straight to the fuzz control via a B500K pot wired in series. I tried it as a divider to ground but I couldn't figure out a good way to make it work without cutting out the other 2 signals.

The B500K may not be the optimum value, the best mix comes at the end of the dial and is very difficult to adjust perfectly to get the sweet spot.

Anyway, now I can blend the dry signal with the low octave just like the original Shocktave as well as blend the dry signal with the upper octave like the Prescription Electronics C.O.B. or mix any of them out completely or mix all 3 together, etc.

[duck_arse]

well, now we come back to that mysterious 220k in the buffer emitter. I'm still wondering how that value affects the drive capabillity of that buffer.

as for you dry pot, I think you should wire it as a volume control, with another mixing resistor, 100k, feeding in with the other 2 100k's. but you'd want a blocking cap somewhere between kuwait and the dry pot.

I've been messing with the shocktave, and thinking of ways to have a clean dry signal to feed the mix instead of the horrible distorted dry from the second transistor. and a volume boost/control. [I really should go and check the original circuit again.]

[Ben Lyman]

Well Duck, I forgot to mention that the first time you brought up that 220k buffer emitter, I had thrown an 18k on there with no ill effects. It had been on there the whole time, so now I just threw a 4k7 on there with no change.

I like your fizz filter on the shocktave output, I used a 10n between the two 47k resistors.

Thanks for the tip about the dry signal volume, I will get on that next.

As for the original Shocktave dry mix, maybe instead of taking it from the boost transistor's collector, just move it to the input buffer's emitter?



edit: no luck on the dry signal volume knob experiments.
It seems like the way I have it now as a variable series resistor is giving me the best results.
In  fact, it is working very well with a reverse audio C1Meg pot.

I am still getting a little of each signal bleeding through all the time which I don't like.
It makes very cool sounds but I would like to be able to thoroughly isolate each signal so I am afraid I might need toggle switches on each.
Better still, maybe a switched pot for each control to turn them on and off as I adjust them.

[brianq]

+1 on EQD Tentacle, it's a bad mama jamma when it comes2 tone & u don't need another pedal 2 drive it cuz it's got plenty of umph 2 boot!

[Ben Lyman]

+1 on EQD Tentacle, it's a bad mama jamma when it comes2 tone & u don't need another pedal 2 drive it cuz it's got plenty of umph 2 boot!

I checked the schematic and it looks just like a Green Ringer to me, which I love. In fact, my schematic posted here is the uh, erm... "Tentacle" with mixable low octave and natural dry signal 

[duck_arse]

for anyone playing along at home that doesn't like the basic fizzzz of the shocktave, there is a fixxe. string a cap, starting about 3n3 up to 22nF, between (Ben's numbers) Q5 base and Q6 base, and it knocks out quite a lump of sizzle.

here's a picture ......


top trace is (my, modified) clean out, middle trace is 100% shocktave out - just right of middle can be seen a short positive  pulse - and the bottom trace shows 100% shock with 22nF between bases (ignore the trigger-lock shift, I'm lucky to get anything at all display) now missing the little spike and some more rounded edges, the sound gets very woof growl.