D*A*M: Ezekiel 25:17 Low Frequency Distortion Generator, 0.15" Vero Layout

So I just worked out why I purchased some Motorola MC1748CG tin can op amps - it was to make one of these.  I've had them in my parts draw for a while, trying to remember what they were supposed to be for.  I thought maybe the Hudson Sidecar, but no, I need a dual for that.

Anyways, here it is, and I may refine this a little more at some stage or post something smaller on regular vero, as this is really for my own purposes - I doubt anyone else will want to make this at this size using these op-amps.   I almost did the full-size one on tagboard, but that was even bigger.

D*A*M EZEKIEL 25:17 LOW-FREQUENCY DISTORTION GENERATOR - VERO LAYOUT

EZEKIEL 25:17 VIDEO DEMO

GRETSCH: Play Boy Harmon Booster

OK, so this one is wide even by my standards - but it will still fit in a 150BB in landscape format.  I could have made it a bit smaller, but once you get past a certain width, why hold back is my theory.

The Gretsch Play Boy Harmon Booster was one of my early vero builds, using a layout by Mirosol on Guitar Effects Layouts (also known as the Jen Harmon Booster).   

It's pretty cool, and a little unusual at the same time - and it's not a booster by the way, it's a distortion.  It has quite a few buffer stages...   I tried a simplified version without the all the buffers, and it's just not the same.

It's open to some simple modding, as the tone section is a Big Muff style tone control.  The long tail pair amplifier arrangement also looks interesting.  

GRETSCH PLAY BOY HARMON BOOSTER - VERO LAYOUT

SCHEMATIC

VIDEO DEMO

FOXX: Tone Machine, BE Mods 2026

Updated Foxx Tone Machine layout on 0.15" vero.  This was inspired by the Aion mods - if you are unfamiliar with the Aion Vulcan, it's a Tone Machine with a modded EQ section (which is great) and an additional bypass option on one of the diodes - also a cool addition. 

I've tweaked a few values to suit my taste - this is not a stock Tone Machine.  

FOXX TONE MACHINE - BE 2026 V1

ADDITIONAL FOXX TONE MACHINE INFORMATION

Credit where credit is due - most of this information is from Aion build documents, which are excellent (go buy a kit, it will be easier than this...)

Transistors

The earlier Blue FTM used 2N3565 transistors with a hFE of around 230 to 245.   

The Red FTM used 2N3565 transistors with a hFE of around 450 - 550 

*I've also seen BC237B listed on the JD Sleep schematic from 2002.  

Treble Capacitor 

The earlier Blue used 3n3.   The Red used 2n7

Tone Control

Yes, it looks a bit like a Big Muff.   Can add a resistor after the treble cap to ground for BMP-like results.

The 4k7 resistor on the bass side of the treble control limits the range of the pot - jumper or remove for a tiny bit more range on the bass side.  

And of course, there is the mid-switch - basically adding more capacitance to the 3n3 treble cap, to boost mids.  I like a little bit of this action, but not too much.  15n is too much for me...  

Q3 bypass cap

Noted as 10uf on the schematic, measured at 22u, which does make a small difference to the bass response (more).  Basically, a 10u cap that is out of spec.

Additional Resistor

Red version had an extra 12k series resistor before the sustan pot, shaving a bit of level off.

Diodes

Use matched diodes in the octave section - originals used generic 1N34A diodes.  Matching just gives a better octave.   

Coupling Caps

Apart fromthe 100n on the input, the original used 10uf coupling caps.  They can be trimmed down to 1uf with no discernible difference.  

Optional Extras

The CBS Arbitier Doubler has a 10uf bypass cap on the emitter of Q1 - but is more gain here really needed?

Can add a 22u cap on the emitter of Q4 to bring the level up, as it can be a bit low.  

ZVEX: Woolly Mammoth

After having played around with some random mic preamps on the breadboard and in LTspice lately, I thought I might go back to basics with a fuzz face derivative - the Zvex Woolly Mammoth.  Brother to the Fuzzolo and Mastoron (they all share the same bones).

ZVEX WOOLLY MAMMOTH - VERO LAYOUT

VOX: Thomas Organ Vox Solid State Amplifier Limiter

A portion of this is based on the limiter circuit in some of the Thomas Organ Vox Beatle amps, which were solid-state amplifiers.  This was meant to protect the power amplifier section from overloading - R.G. Keen has explained it way better than I could here on Premier Guitar.

So far, I've only tested the single circuit on a breadboard - and it sounds OK.  Kind of like a fancy Electra Distortion with more range.     

SCHEMATIC

LT SPICE TRACE

It looks similar to this on my scope on the bench - I'll record it next time and post the results.    

TRACE 2

Same again, but now twice the fun - starting to look more interesting.