The new 125B design platform

I spent a long time during the first half of this year designing a new foundation that will serve as the basis for new Aion projects going forward. I completely revamped my design process, going through every aspect of project creation, and the first product of that revamping is a new set of design standards for projects going forward. Here’s what it will look like.

  • Unified drill template system for consistency between projects
  • Top jacks (in, out, DC) for all projects
  • Space for a 9V battery where possible
  • Integrated bypass switch boards for all projects
  • Redesigned documentation template

New projects

These new projects are available today. More will be coming very soon.

Graviton Metal Distortion - Boss HM-2 Heavy Metal DIY Project PCBGraviton – BOSS HM-2 Heavy Metal

A brand new Aion project that recreates a favorite among extreme metal guitarists. (Not to be confused with the MT-2 Metal Zone!) The Graviton is a great high-gain pedal that works in many different styles of music besides metal, with a well-rounded tone that is still capable of some very unique sounds.

The most famous use is the Swedish death metal trick where you put all the knobs on 10 and run it into a low-end solid state amp. This was used by a number of extreme metal bands in the 1990s all the way to the present day.

Graviton Metal Distortion →

Refractor Professional Overdrive - Klon Centaur / KTR DIY Project PCBRefractor – Klon Centaur / KTR

An updated version of the Refractor, which now has the distinction of being the first true clone of the Klon KTR. The Buffer / True Bypass switch is now integrated into the circuit. This was one of the most requested features for the Refractor!

While some other Centaur clones have switchable true bypass, they all used a simplified version that left the buffer mode slightly changed from the Centaur. I didn’t want to settle for that, so after a great deal of research, I’m happy to say that I was able to replicate the real thing. To my knowledge this is the first time the KTR’s switching schematic has been published or implemented in any design outside of the KTR itself.

Refractor Professional Overdrive →

Halo Distortion/Sustainer - EHX Big Muff Pi DIY Project PCBHalo – Electro-Harmonix Big Muff Pi

The Halo has been updated with a new version of the mids control. One complaint I had about the AMZ “Presence” control (which was an optional 4th knob on the original Halo) is that its EQ curve isn’t exactly the same as a normal Muff at any setting. So I turned this into a DPDT switch with 3 modes: mid scoop (the stock Muff setting), flat mids, and mid hump. This way you can get the tonal flexibility without losing the character of the stock circuit.

In addition, it’s been made easier to build a 3-transistor variant such as the Jumbo Tone Bender. To cut down on decisionmaking complexity, I removed the option for the JFET output stage from the Fire Red Fuzz.

Halo Distortion/Sustainer →

Aurora Compressor/Sustainer - Ross / Dyna Compressor DIY Project PCBAurora – Ross/Dyna Compressor

The Aurora gets a few upgrades: first, moving from the CA3080 to the LM13700, which is a dual version of the 3080 that is still in production and very easy to find. Second, adding a new output stage that cuts down significantly on distortion that is produced by the envelope detector. (This is optional, and the original output stage can also be used.) Third, making the Release switch into a knob, and including space for tapering resistors in parallel with the pot so that a more common 500kB pot can be converted into the required value of 150kC.

Aurora Compressor/Sustainer →

Cerulean Amp Overdrive - Marshall Bluesbreaker DIY Project PCBCerulean – Marshall Bluesbreaker / JHS Morning Glory

The Cerulean has undergone some revisions. It still supports any of the Bluesbreaker, King of Tone or Morning Glory versions, with the exception that the option for the MG’s Bright Cut switch has been removed because it’s really pretty useless. (There are already two more treble-focused controls with the on-board Tone knob and the internal Presence trimmer.) So what we’re left with is one switch for Soft Clipping (low, high or none), another for Hard Clipping (low, high or none), and the option to use the Morning Glory’s JFET gain stage at the output.

Cerulean Amp Overdrive →

Azimuth Dynamic Overdrive - Hermida Zendrive DIY Project PCBAzimuth – Hermida/Lovepedal Zendrive

A good first build for people just getting into the hobby. Nothing new in the re-release, but it’s a fantastic-sounding circuit that is at home in any rig.

Azimuth Dynamic Overdrive →

What will happen to the existing 1590B projects?

These 125B projects will not replace the 1590B versions. While I won’t be designing new projects for the 1590B going forward, I expect to keep the existing 1590B projects in stock for the foreseeable future, as long as they continue to sell. Many of the updated 125B versions are different in some way, and there are plenty of people who may prefer the 1590B versions.