Suggestions for OD/FUZZ/OSC build *completed w/video*

[Ben79]

Hi guys,

I've got a nice old blue anodised box that has a three position switch already built into it. I've been asked to put a circuit in there so the 3 positions select between overdrive, fuzz and oscillation. There will be a volume control but nothing else.

Any ideas?

[lordgalvar]

os mutantes with a low gain mode for the over drive? I think it will oscillate if you take out the front caps and have the signal go direct into the first transistor...but you could just put a loop. Could work?

Or do something like it cuts the second transistor out of a tone bender/fuzz face or something that makes a boost like a rangemaster and the third mode has a feedback loop? Maybe look at zvex designs? Just throwing stuff out there (I don't really know).

Two bazz fuzzes with a third mode for feedback?

Or maybed just a rat, with mods for more gain and osc.

[Nocentelli]

What kind of switch, SP3T? SPDT centre off? more poles? That will determine which kind of circuits you can build around it.

[Ben79]

os mutantes with a low gain mode for the over drive? I think it will oscillate if you take out the front caps and have the signal go direct into the first transistor...but you could just put a loop. Could work?

I like the Os Mutantes idea - always wanted to build one.

What kind of switch?

The switch is a 3p4t rotary - nice!

The enclosure has also got a little 'push to make' momentary switch on it I could incorporate somehow….

[KaosCill8r]

os mutantes with a low gain mode for the over drive? I think it will oscillate if you take out the front caps and have the signal go direct into the first transistor...but you could just put a loop. Could work?

I like the Os Mutantes idea - always wanted to build one.

What kind of switch?

The switch is a 3p4t rotary - nice!

The enclosure has also got a little 'push to make' momentary switch on it I could incorporate somehow….

The OS Mutantes fuzz is a good choice. One of the more unique sounding fuzzes of the vintage fuzz world. I built one a couple of months ago from a kit. Has a switch to take the clipping diodes out, a high cut control and a control to change the diodes from asymmetrical to symmetrical clipping. It is a very cool sounding and versatile pedal.

[Ben79]

I've built it and after some errors have finally got it working.

I've wired up the rotary switch to go straight in to the 0.003 cap at position 1, bypass it at position 2 and bypass both input caps at position 3. This makes for a good trashy overdrive and a grindy thick fuzz in positions 1 and 2 respectively but I'm just getting silence from position 3.

Can anyone recommend a way I could try to make this circuit oscillate (as musically as possible)? I have a latching spst and a push to make momentary on the enclosure that are still sitting unused. I'd like to add a special mode selectable with the spst so the momentary makes it do something like shifting the pitch of the oscillation or making it sputter by starving the circuit…something interesting.

Here's the schem:

[Ben79]

I worked it out!

I made a feedback loop between the input and the q2 collector junction and installed a 100k pot to control the feedback frequency. Setting 3 on the rotary now gives you feedback at a chosen frequency and the momentary switch will create feedback any time you push it. Works ace!

[lordgalvar]

Awesome! Glad the circuit worked out for you and thanks for the notes...I actually had a bit of a bit of a problem with my build (it was that cap...my wife said it was wrong...should have listened...she just guessed haha).

Can't wait to see a picture of the thing.

[Ben79]

Thank YOU and everyone else for the suggestions and help. I probably wouldn't have tried it or persevered when it didn't work if not for the forum.

And now it's finished and does exactly what I wanted - I'm proper stoked.

I'll take pictures tomorrow and try and record some sounds.

[Chankgeez]

[lordgalvar]

Yea, it will be awesome to check it out.

This forum is awesome.

[Ben79]

Never made a video demo before but here y'all go…
https://youtu.be/pxdv5DpHE-E

Fuck, I don't know how to embed videos - thanks Lordgalvar below.

[lordgalvar]

Never made a video demo before but here y'all go…
[youtube]http://www.youtube.com/watch?v=pxdv5DpHE-E[/youtube]

[lordgalvar]

That sounds amazing. Way better than I thought it would with the osc. Great job man! Also, great demo!
The case and design look freaking exceptional.

[KaosCill8r]

That is nasty and so awesome dude, also very cool demo. Showed everything you needed to show Every time you pressed that little oscillating button the cat sitting next to me on the couch freaked. He's alright though, he's gone back to sleep now.