AM8109 JP-8 VCF v2

Roland Jupiter-8 Low Pass Filter replica

This module is an accurate replication of the Low Pass Filter from the legendary Roland Jupiter 8, inclduing the unique Q compensation.

A warm sounding filter with smooth frequency control and a resonance that gradually increases up to full self oscillation, a sound very reminiscent of the early 1980's. Whilst the original Jupiter 8 filter did not self oscillate, we have added this feature, trimmed to avoid overload and waveform clipping.

The difference between 2 and 4-pole modes is not dramatic, with the 2-pole mode providing a more gradual cutoff slope, lower volume and silky sound.

This latest version of the AM8109 was launched in 2022 and is a redesign of the original to use red LED slider pots, improved panel graphics and a narrow 10HP width.

This module is an accurate reproduction of the Jupiter 8 low pass voltage controlled filter, using the AS3109 OTA chip in the filter core. The design has been updated to use modern components with high quality capacitors in the signal path and filter core.

There are front panel controls for adjusting the Cutoff Frequency and Resonance as well as the level of 2x control voltages and 3x audio signal inputs. Resonance is smooth and controllable into self-oscillation. Q compensation ensures no significant drop in signal level as resonance is increased.

There are six 3.5mm jack sockets on the right of the front panel;
2x audio inputs (INA, INB)
3x control voltages (KYBD, MOD, ENV)
1x audio signal output
The slope of the filter can be switched between 12dB and 24dB using a red push button, with a red LED indicator.

https://www.amsynthstore.co.uk/AM8109_JP-8_VCF/p1461448_19925547.aspx