fun octave circuit

[frank_p]

Can anyone please make a perf layout for this? 

I'm also interested in a perf layout...or vero 

Hey my friends, I think you should start a topic together with this schematic. Ask for help:
- in schematics reading
- how to use DIY layout creator
- Outboard wiring
etc.

As Doug said it's a good schematic to start with and poeaple will help you, I am sure.
This is an occasion, not only for having a new effect, but also for learning and starting discussions/having-contacts with the folks on this forum.

[ppatchmods]

I just attempted to put this in vero form. It's my first vero layout, so I'm not even sure what I'm doing. Please give it to me straight!

[DougH]

Seems right. I'm not that familiar with vero though. One of the vero builders should double-check this.

[foxfire]

from a quick glance i believe you need trace cuts under C1, C2 and R1.

[mac]

This circuit is a Bazz Fuss.
I took the output from Q1 collector and guess what? Bazz Fuss. The second transistor is acting as a diode.

Q2 can be replaced with a silicon diode: Q1 collector -> diode -> 5k to 10k -> Q1 base.
The output from the junction of the diode and the resistor.

If you wire a darlington Bazz Fuss you can add a switch to go from octave to BF:

10k from Vcc to Q collector
Q emiter to gnd
Q1 collector -> diode (black line to base) -> 5k to 10k -> Q1 base (I got best octave with a 5k, depends on the darlington)
A stomp switch to go from BF to Octave.

Enjoy

mac

[ppatchmods]

Foxfire you are correct! I missed those cuts. Thanks

[asfastasdark]

You could cut off an entire row by reducing the lead length of R2 and the jumper next to it.

[ppatchmods]

Thanks! I'll do that. Does the circuit look right to you?

[tiges_ tendres]

Foxfire you are correct! I missed those cuts. Thanks

I havent checked the layout for errors, but I can see a few ways to make the board smaller.

If you orient your caps vertically rather than horizontally you could save a couple of columns, or save one column and add a pulldown resistor on the circuit input.  If you do this, you wouldnt need the track cuts under the caps which I always find fiddly.  You will need track cuts in other places if you move the caps though.

Also, look up power supply filtering.  This would be a good time to add that to the circuit.

[doug deeper]

ok here is a much improved version!
the darlington can be what ever (home made even)
the octave is now way more pronounced.
thanks for mentioning the closeness  to the bazz fuss, it gave some good inspiration.

[mac]

Note that with a stomp switch you can short the feedback resistor and move the output to the collector to have a bazz fuss.

mac

[petemoore]

  It does look like fun, now that I can read it, the schematic is fine, the Q1e ground marking, I think was in my blind spot.
 

[DougH]

ok here is a much improved version!
the darlington can be what ever (home made even)
the octave is now way more pronounced.

As GWB would say- "It looks like it should have much-improved intermodularityations."

[ppatchmods]

Can someone verify this one? I think I'm gonna try it next week!

[doug deeper]

ok so i played with this a bit more today and there is a pretty big drop in gain, so a recovery stage would be in order.
the last stage of a muff would do.

[alex frias]

Do you think it desperately needs a Tone control?

[doug deeper]

i dont think it really needs a tone control, its not overly bright, and if there is too much low end that can be addressed with the output cap/resistor.

[alex frias]

Thanks for the reply, I have lots of fuzzes and octavers, it's always very seductive to experience those very small circuits so self containeds and effectives..

[Steben]

I would suggest putting an emitter follower direct to the resistor/diode connection, with a 4k7 resistor or so at the emitter. It's a trick that works fine on a bazz fuss too. This gives a high impedance at the end of the circuit, which raises the gain of the stage as well and makes an ideal front for a tone control.

[John Lyons]

Do you mean to say that it give a low impedance?
Usually an emitter follower has a high input imp and a low imp out that works to buffer a tone control.

john