The Theremin Fuzz

[Freppo]

Hi folks :)

Here's a new project I released a while ago.



The Theremin Fuzz is a guitar effect that produces a sound similar to a real theremin instrument, but controlled with the input from your guitar. Circuit-wise it's very similar to the Into the Unknown (that can also do theremin sounds and alot more), but in a much smaller format with less controls.

I have made a verified vero layout for it that you can find here:
http://www.parasitstudio.se/thereminfuzz.html

The vero layout is pretty big compared to the PCB, but it will fit in a 1590B with some careful measuring.

I hope you like it. :)
Cheers / Fredrik

[Neil mcNasty]

Wow!
Thanks a lot!
Been hoping for this to happen!
U Rock!

[mug]

Awesome - last weekend I was literally about to ask if you'd make a vero of this one but thought "let him sell some pcb's first..."
So generous, thanks a lot man - have to order some chips but this is definitely one of my next builds!

[mug]

This is the coolest circuit I'll probably ever build - fired up instantly and sounds freaking f*ng fantastic!

Thanks Freppo for sharing this - so cool...!



One thing - vol 2 is output (in the notes it says 3...)

[Freppo]

Cool. I'm glad you like it! :)

Ops, yes it should read vol 2 to output.
Thanks for spotting that mistake. Layout is updated.

Cheers
/ Fredrik

[Kinski]

Just built this. Really cool pedal. Thanks Freppo!

[tentomushi]

Hey Fredrik, thanks for this fantastic design.
It really sounds amazing!
Built this recently and it's great, just what I was looking for.. Cheers

[traktop]

I´m building this for sure!!!!
Anyone tried this after buffers?

[mug]

I have it somewhere in the chain that starts with a Little Black Buffer and it works fine! If you use single coils it tracks better with a compressor or boost in front though.

[traktop]

Thanks

[nostradoomus]

Ordered the pcb version. This thing is so cool! Awesome job Fredrik! Now i need more for my friends.

I love the gliss effect you get when a note is released...amazing.

[Freppo]

nostradoomus wrote

Ordered the pcb version. This thing is so cool! Awesome job Fredrik! Now i need more for my friends.

I love the gliss effect you get when a note is released...amazing.

I'm glad you like it :)

[nostradoomus]

Every pcb I've got from you has been golden! Can't wait for the New Wave 8)

[traktop]

I've built It, and is insane!
Even just because of the unique fuzz voice is worth It.
The theremin is great, but I was wondering if there is something I could play with, (filtering or gain stage I guess) , in order to improve the tracking with my p90/ les paul and strat guitars. I've tried with both neck pick ups with the tone control rolled off  and just seemed  to track reasonably on the first 3 strings, from 3th to about 15th fret.
The sensitivity didn't seem to help here as the important stuff seemed to be happening before It.
I've built 4 boards and all of them seemed to behave more or less the same way. Maybe I could try replacing the "theremin" chip by new ones and see , but I dont know which is It.
Cheers Gilberto.

[traktop]

I´ve just made a demo

https://soundcloudx.com/nightcubefx/theremin-fuzz

[Shaggy45]

Which caps do I change to make the fuzz work better for bass?

[Freppo]

Shaggy45 wrote

Which caps do I change to make the fuzz work better for bass?

To make it more bass friendly, I suggest changing the 1nF cap to a larger value. The 1nF cap is part of a lowpass filter at the output, so it will cut treble.

For a normal fuzz you can simply make the dc blocking caps in the signal path bigger, but that's not really the case here. Even if you bump up the dc blocking cap values you won't hear a difference. That's because it turns the signal into a square wave which adds alot of odd harmonics. These harmonics are heard as mid and treble and will be alot prominent than the low end. That's why I have the lowpass filter at the output, so cutting treble is probably the way to go, to make it darker thus letting the low end be heard.

[Freppo]

traktop wrote

I've built It, and is insane!
Even just because of the unique fuzz voice is worth It.
The theremin is great, but I was wondering if there is something I could play with, (filtering or gain stage I guess) , in order to improve the tracking with my p90/ les paul and strat guitars. I've tried with both neck pick ups with the tone control rolled off  and just seemed  to track reasonably on the first 3 strings, from 3th to about 15th fret.
The sensitivity didn't seem to help here as the important stuff seemed to be happening before It.
I've built 4 boards and all of them seemed to behave more or less the same way. Maybe I could try replacing the "theremin" chip by new ones and see , but I dont know which is It.
Cheers Gilberto.

Hey Gilberto,
I just noticed your comments in this thread. Ops... Sorry for not replying sooner.
The notification emails must have been lost in my messy inbox..

You can improve the tracking slightly by putting a 1nF-2.2nF cap across the 2.2M resistor. This will make you able to dial down the threshold for the schmitt trigger (the trimmer) alittle bit aswell without the circuit going into sputtery oscillation, and the closer you have the trigger to where it starts to make noise, the better is the sustain. Other than that, the best thing to do is to add a boost at the input, and maybe a simple RC lowpass filter after the boost (like a 10K in series with a 10nF-100nF cap to ground).

BTW, awesome demo. Thank you for sharing. :)

Best regards
/ Fredrik

[Shaggy45]

thanks fredrik. I’ll give it a go.