Vero Layout: The Gristleizer

Here's a really ugly vero layout I did for the classic 'Gristleizer' circuit, the first circuit I ever took a probe to and figured out how it worked. I learned a lot from the circuit, as it provides elements of electronics present in both guitar effects and synthesizers.

It certainly hasn't aged well, the filtering is pretty terrible and some settings are borderline inaudible, with some knobs not doing anything in 70% of their settings, and using 5 LM741s seems ridiculous, so this one uses a TL074 and a TL072, with the voltage doubler hidden off-board (I had this in console style case that I never finished). A lot of fiddly parts chained together.

I've built several of these now and they've all come off really well. FuzzDog does a great PCB if you're in the UK too: https://shop.pedalparts.co.uk/Gristleizer_-_Mad_Modulations!/p847124_15740439.aspx

Anyway, the layout:

I told you it was ugly!

I often wondered why nobody had produced a vero layout for this, and then as soon as I put pen to paper, I realised why. Too many jumpers, too many cuts and too many specific parts needed to commit to making this unless you really want to.

The schematic I made this from was a beautifully neat Eagle schematic which now seems to have been expunged from the internet. I have a copy but shan't post it here as I cannot remember where it was from and wouldn't want to host it without asking permission first. But if you fancy it, have fun building this.

Self-verified, as I had this working for a while, and it sounded near identical to the three I bought from Fuzzdog.

New Effect: Screaming Red Rabbit Fuzz

So here's a happy mistake!
Confessions up front. I was trying to make a Seamoon Funk Machine. I'm sorry.
Sorry that I was trying to make an auto wah pedal, and sorry for not succeeding.

Fortunately, I can bring to you, hypothetical reader, something else entirely. I present to you the SCREAMING RED RABBIT fuzz pedal.

And I'm posting the schematic AND a veroboard layout for you to make yourself.

The Screaming Red Rabbit is, while technically unassuming in its low part count and common components, a rather serviceable fuzz pedal. It's almost like a ZVex Fuzz Factory, in that it squeals with delight, self-oscillates, and generally won't behave its damn self.

There are four controls.

• Definition (envelope sensitivity)
• Density (envelope gain)
• Frequency (frequency of the low-pass filter, a sign of its origins as a 70s filter pedal)
• Volume (how loud it can do what it does)

I fiddled around with the bit in between the envelope follower and the filter op amp for quite a while until I found a decent combination, but got it to do some pretty wacky things on the way. At one point it was very nearly a tremolo. A horrible, horrible tremolo.

Schematic!

And a vero layout for you to chew on:

Your homework is to try making this, verifying my layout and letting me know if it sounds as awesome as mine (somewhere between a Prunes & Custard and a Smashing Pumpkins-esque op amp big muff) or if it is totally horrible and I am very wrong. Bonus points if you can identify the origin of the name I have given this thing.

Enjoy!