Pedals for Sale - EffDub Audio

After much tweaking and some setbacks, I’m pleased to announce that my take on the classic “hard-rock / vintage metal” sound is, at long last, ready for public consumption. This one is 100% “discrete” in the sense that there are no integrated circuit components (operation amplifiers or other ICs). It’s all field-effect transistors doing the amplifying and clipping…there aren’t even any clipping diodes in this circuit. There ARE diodes in the circuit, but they are for polarity and over-voltage protection (not in the audio path).

What does it sound like?

To me, it sounds sort of like a pushed Marshall JCM800 or an Orange Rockverb cranked up. With the GAIN set high, it’s got boatloads of compression and sustain and also a lightly fuzzy low end (but still fairly tight). At lower gain settings, the bass cleans up. It does NOT sound like the classic Mesa high-gain tone.

Bands I think it sounds appropriate for: Black Sabbath, AC/DC (lower gain settings), Guns n’ Roses, Ghost, Faith No More, Iron Maiden, Van Halen, Ratt, Poison, and a bunch of other hair metal bands. This very subject, of course.

Circuit Details – Basic Metal

The Basic Metal is a total of five cascaded / series gain stages: a single JFET input amplifier (boost) driving four MosFET amplifiers, followed by a simple variable low-pass filter tone control. The GAIN control sits between the JFET boost and the rest of the circuit. There is also a high/low gain switch that toggles a bypass capacitor on the JFET’s source pin. The TONE control is taken directly from the venerable ProCo Rat (why mess with simplistic perfection?).

Additionally, there is an output gain trimmer that sets the gain of the final MosFET amplifier. This is to fine-tune the max gain available and allow for compromise between gain and noise. And finally, there is a bias trimmer to dial in the JFET and a bias pad to easily read the voltage with a multimeter.

Availability

I will be building some fully finished pedals using the Basic Metal circuit, with laser-etched wood faceplates. I will also be making the boards available so folks can build their own. I will post an update when things are progressing. Final boards have just been ordered, so it shouldn’t be long.

Pedals for Sale

August 31, 2024 effdub

Actually, it’s a different tremolo coming first: CMOS Eisley

Just got these boards in today and have begun the first prototype build. It’s an optical tremolo with both the audio path and LFO made from a single CD4049 CMOS hex inverter. Despite having it all function in a single IC, there is no LFO ticking in the audio. Two of the inverters are the audio path (input and output amplifiers), and three more inverters are arranged as a low-frequency oscillator. And the last inverter is unused (I may do another iteration later that uses this last inverter to add a bit of grit/drive).

There are three controls: Speed (pot), Depth (pot), and Triangle/Square (switch). The switch controls the wave shape of the LFO. Be default, the LFO products a VERY square output. To try to smooth this out as much as possible, I added a very large capacitor as a rudimentary low-pass filter on the wave. The result is pretty close to a triangle wave shape. And the switch allows you to choose which wave shape you want to use (obviously). There is also an LED to indicate LFO speed, and it is lit even when the pedal is bypassed. The pedal will be available with either a standard 3PDT mechanical bypass switch or with a relay-driven soft-touch bypass switch (modest upcharge for the latter).

I hope to have a demo video posted soon, and after that I plan to sell these primarily through a local music shop (who will ship pretty much anywhere), but I will also sell direct if someone would prefer that.

Pic of the mostly populated board:

Pedals for Sale

August 4, 2024 effdub

Coming Soon: Tap Temp Optical Tremolo

I’m pleased to announce the first of a few pedals that will be hand built by me in small batches and sold as cheaply as I can manage. There are cheap Chinese pedals galore these days, but I want to try and get as close to I can to slave-labor prices but made in the USA. Think of it as “shabby chic” or maybe “bespoke” rather than old-school “boutique.”