The Wonderful Audio Apex Distortion is a distortion pedal built around the circuit of the ProCo RAT, but it is not a copy of one. Its maker's account of the pedal on Delicious Audio puts it this way: "This is not a clone. It is a reimagination of a classic." The project "started as a RAT-based circuit and ended up becoming its own (still vaguely ratty) thing"1.
How the circuit works
The Apex keeps the LM308 operational amplifier at the heart of its gain stage, the chip the designer originally set out to experiment with from the vintage RAT. Around it, three departures from the RAT shape the pedal's character1.
- Reworked LM308 voicing. The gain stage's voicing was reworked "aimed at a crisper high-end and flexibility at any gain range"1.
- Mixed clipping. A combination of "a mixture of diodes and an LED" was chosen for "a blend of smoothness and crunch"1.
- JFET front end. A JFET gain stage was added before the LM308 to recreate the effect of boosting the signal fed into a RAT, as with a boost pedal in front of it1.
The tone control and output buffer
The tone stage works like the RAT's, as a classic low pass filter, with one deliberate difference: it is reversed, so turning the knob left gives a darker sound and right gives a brighter one1.
At the end of the circuit sits a JFET buffer, which "also adds some color as it saturates"1. That makes the output stage part of the sound rather than a neutral stage, in the same spirit as dedicated buffer designs that are voiced rather than transparent.
Where it came from
The designer has said the project began after watching a series of YouTube videos from Demos in the Dark called "Rat Week". The pedal then "went through many revisions", including a version that was almost released before being reworked further1.
Videos
ambienttrash
Demos In The Dark
Fuzzed Drones
Questions
Is the Wonderful Audio Apex Distortion a RAT clone?
No. Delicious Audio's product page states plainly: "This is not a clone. It is a reimagination of a classic." The circuit started as a RAT-based design and, after many revisions, ended up as its own pedal, one the designer still describes as vaguely ratty. It keeps the RAT's LM308 chip and low pass filter tone stage but reworks the voicing and adds a JFET front end.
What chip does the Wonderful Audio Apex Distortion use?
It uses the LM308 operational amplifier, the same chip found in the vintage RAT. The designer's original idea was to experiment with the vintage RAT's LM308 chip, and the project grew from there into a reworked gain stage voicing aimed at a crisper high end.
What kind of clipping does the Apex Distortion have?
The clipping section combines a mixture of diodes and an LED. The designer combined them to get a blend of smoothness and crunch, rather than the character of diodes or an LED alone.
Which way does the tone knob turn on the Apex Distortion?
The tone stage works like the RAT's, as a classic low pass filter, but it is reversed: turning it to the left gives a darker sound and to the right a brighter one, the opposite of the RAT's layout.
Who designed the Wonderful Audio Apex Distortion?
The pedal was designed by the builder himself, who has said the project began after watching Demos in the Dark's YouTube series called "Rat Week". The design went through many revisions, including a version that was almost released before being reworked further.
Sources (1)
- Wonderful Audio Apex Distortion, Delicious Audio, 2022-05-11