Amethyst Analog Delay

The Amethyst Analog Delay is based on the BOSS DM-2, which was originally released in 1981 and is still widely considered to be one of the best delay pedals ever made.

The DM-2 circuit uses the MN3005 bucket-brigade delay (BBD) chip, which has 4,096 stages and makes the unit capable of around 300ms of delay time when properly calibrated. It also uses a compander to significantly improve noise performance for the delay line.

In 1982, Boss updated the circuit to use the MN3205, which has better audio specifications at the expense of lower maximum voltage and headroom. This is called the “Second Edition” or DM-2 V2. There are no actual changes to the audio portion of the circuit, but the BBD and clock run on inverted power so the PCB had to be modified slightly to accommodate either version.

For many years, the DM-2 V1 was out of reach for most DIYers due to the scarcity of the MN3005 and MN3101. However, with the Xvive reissue of the MN3005 released in 2015 and Cabintech’s CT3101 clock released in 2023, the classic circuit is once again convenient (if not cheap) to build.

The Amethyst PCB has jumper pads so you can choose either the MN3005/MN3101 or the MN3205/MN3102 chipset depending on availability. Otherwise, it is a direct adaptation of the original DM-2 with no modifications or substitutions.

We have also included a few extra components so that you can build the Way Huge Aqua Puss, which is a slightly modified clone of the DM-2 from the mid-1990s. See the build notes section in the documentation for more information.