The 12HP wide AM1044 is a re-issue and expansion of the original AM8044 from 2013, using the CoolAudio V2044A chip and some design ideas from the SSI2144 datasheet. The V2044A delivers a fantastic sounding transistor ladder filter, which we have added some amazing Q compensation to.
AM1044 circuit The V2044A is a re-imagined SSM2044 chip which found its way into the various Korg synths like the Mono Poly in the 1980’s. In 2013 I issued the AM8044 based around this chip, but its was a low volume run due to its scarcity. Fast forward 13 years and the V2044A chip is easy to source, plus some ideas in the SSI2144 datasheet about how to add Q compensation.
The V2044A chip creates a 24dB cascading ladder filter, with an OTA circuit providing Q compensation, which ensures no loss of bass response when Q is driven into self oscillation. The Q circuit also has a Q CV input (with an attenuator) for achieving variable feedback from a CV input. The self oscillation goes down to below 20Hz.
The module has a two way LED circuit which has a green LED to show normal signal levels and a red LED to show boosted levels. Amber LEDs continuously lit up the CV potentiometers.
Connections & Controls
- Three audio inputs, with the first two having a volume control
- Four CV inputs to the VCF, three with a level potentiometer
- Large control knob for filter CUTOFF
- Q is controlled via a dedicated resonance potentiometer
- Q CV input and level control
- Two way switch selects whether Q compensation is on or off
- ARP 2500 style control knobs
Outcomes & Availability The AM1044 was developed during the Spring of 2026 and a demo will be shown at Synth East 2026.
