14 HP
35 mm deep
Current Draw
? mA +12V
? mA -12V
? mA 5V
$176 Price in €

This Module is currently available.


Low & High Pass Jupiter 8/4 Filters

Description This module is replication of the Low Pass and High Pass Filters from the legendary Roland Jupiter 8 and 4. This is a 2 and 4 pole OTA design that Roland first used in the Jupiter 4 in 1980, replacing a discrete version of the filter which took up more PCB space.

This is a warm sounding filter with smooth frequency control and a resonance that gradually increases up to full resonance, just before self oscillation, a sound very reminiscent of the early 1980's. The original Jupiter 8 filter did not self oscillate, and we have retained this configuration. However the customer can set the filter to self oscillate by adjusting a PCB trimmer on the rear of the module.

The difference between 2 and 4-pole modes is not dramatic, with the 2-pole mode providing a more gradual cutoff slope and silky sound. The high pass filter provides a gradual cutoff of low frequencies.

The AM8109SE is a new version of the 2010 AMSynths design, with slide potentiometers and a skiff friendly module depth of 35mm.

Eurorack Module: 14HP wide
User Manual: AM8109 Quick Start Manual

This module is an accurate reproduction of the Jupiter 8 low pass voltage controlled filter, using the AS3109 OTA chip in the filter core, as well as the high pass filter that uses an AS662 chip. The design has been updated to use modern components with high quality capacitors in the signal path. It delivers a very warm and smooth sound.

There are front panel sliders for adjusting the Cutoff Frequency and Resonance of the low pass filter, and level control of 3x control voltages (MOD, ENV and KYBD) and 2x audio signal inputs. The high pass cutoff frequency is adjusted using a rotary potentiometer with an original Boss coloured control knob.

There are five 3.5mm jack sockets at the base of the black anodised 2mm front panel;
2x audio inputs
3x control voltages
1x audio signal output
There is an audio output jack at the top right of the module. The slope of the filter can be switched between 2 and 4 poles using a small slide switch, and the envelope CV signal can be inverted using a second slide switch.

The module comes with a set of M3 mounting screws and washers, and a standard Doepfer power cable.


Product Code: AM8109SE
Product Condition: New
Weight: 300g


Ø 5.00 (1 Votes) Average Rating
submitted Feb 21st, 19:11 by t1m3 | last Change Feb 21st, 19:34 by t1m3

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