AM8104 JP04 VCF

14 HP | AM8104 JP-4 Filters | User Manual (PDF) | ModularGrid | You Tube

OVERVIEW This module is replica of the filters from the legendary Roland Jupiter 4 that was released in 1978. The AM8104 has two filters; a 4-pole low pass filter is a typical 1970's Roland OTA design, and a single pole OTA high pass filter.

DESCRIPTION This module uses BA6110 OTA chips in the filter cores and high quality polypropylene filter capacitors. The design includes buffering Op Amps to interface to Eurorack modular levels, and the filter uses an OTA in the resonance feedback loop. 

There are front panel controls for adjusting the Cutoff Frequency and Resonance, as well as the level of 2x control voltages and 2x audio signal inputs. There is a small slide switch to select the keyboard signal into low pass cutoff (OFF, 50%, 100%). Resonance is smooth and controllable into self-oscillation. The keyboard signal is from the pitch CV in the 16-pin Doepfer power connector.

There is a central slide potentiometer with LED that controls the High Pass filter cutoff frequency, which becomes increasingly apparent at the top of the slider range. The AM8104 is hand built with high quality components, including Wima polypropylene capacitors, Alpha potentiometers, and traditional black phenic control knobs with spun aluminium inserts.

CONNECTIONS There are five 3.5 mm jack sockets on the base of the front panel:

• 2x audio inputs
• 2x frequency CV inputs
• 1x audio output
  
  

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

PRODUCT STATUS: PRODUCTION