Distiller
Filter-Based Preamp for Bass
"I have never been this impressed by the electronics in any bass I've either owned or built! [...] The filters are amazing and I really find that the LFC complements them perfectly."
– Geoffery St. Germaine
stgermaineguitars.com
Having owned several Alembic basses, I've always found their electronics to be truly special. Unlike most other basses using passive tone controls or conventional 2- or 3-band EQs, Alembic basses come equipped with a unique 12dB-per-octave low-pass filter that features a widely adjustable cutoff frequency and a resonant peak just before the cut. With just one knob, you can access a very wide range of tones, from the darkest dub and reggae sounds to the brightest slap and funk tones and everything in between.
While synth players routinely use resonant filters, they are not common among bassists, who may only encounter them on a few high-end, boutique instruments.
Initially I built an exact replica of the Alembic filter, which performed exceptionally well. However, I later found some opportunities for improvement. Power optimizations tripled the battery life. Additionally, I made a few modifications to ensure compatibility with virtually any bass or stomp box. This was necessary because the Alembic filter utilizes an uncommon grounding scheme that is not compatible with the way most basses and pedals are wired.
Version history
First edition
-introduced in December 2020
Second revision
-adds Alembic-compatible Molex headers, enabling drop-in replacement of the original filter
-adds an output summing resistor, making it possible to combine two or more Distillers by simply paralleling their outputs, as if they were passive pickups.
Third revision
-supports two different potentiometer types on the same board. The original grey pot is extremely hard to source, so I switched to a smaller, green potentiometer from the same top manufacturer. I added the Special Edition designator (Distiller SE) to distinguish it from the previous Distillers.
4th revision (introduced in March 2024)
-Molex headers replaced with a ubiquitous inline pin header
-the Q switch gets its own little circuit board
-noise floor even lower than Rev3 (-103dBu vs -99dBu).
- June 2024: dropped the "SE" suffix. It became redundant since all Distillers have been "SE" for over a year and this is unlikely to change.
Specifications (revision 4)
Input impedance: 1 MΩ
Output impedance: 2.7kΩ
Supply voltage: 9V or 18V
Idle current draw: 0.3mA
Battery life (alkaline): 1500 hours
Noise floor: -103dBu
Max unclipped output: +12dBu
Dynamic range: 115dB
Cutoff frequency range: 250Hz - 8kHz
Filter slope: 12dB/octave
Resonant peak (Q switch): 0 / +5 / +10dB
Gain adjustment range: +3 to +16dB
Board size: 33x23mm
Potentiometer: sealed, long life (100,000 cycles), conductive plastic. Ø6mm shaft, M7x0.75 bushing
Official Distiller Demo
Combinator / Sean Fairchild having fun with his new Distiller
(Check out his other videos too, he's incredible!)