DOEPFER A-121s Stereo Multimode Filter User Manual
- June 3, 2024
- DOEPFER
Table of Contents
MUSIKELEKTRONIK GMBH
ANALOG MODULAR SYSTEM A-100
A-121s Stereo Multimode Filter
A-121s Stereo Multimode Filter
121s Stereo Multimodule VCF
Position and function of the pin headers / jumpers Board B
= factory settings
To change the jumper settings the two boards have to be disassembled
temporarily. For this the two screws of the distant bolts have to be removed
and the upper board carefully moved off the lower board. Pay attention to the
correct alignment of the connectors JP1 and JP2, that are used to connect the
two boards, when the module is re-assembled !
According to the positions of the jumpers plugged on the pin headers
JP3/JP4/JP5/JP6 the control voltage inputs QM/TM1 and QM/TM2 can be used to
control the resonance and/or type of the filters in different ways (QM means
Q Modulation or resonance modulation, TM means filter Type Modulation L/N/H/B)
JP3: Jumper installed QM/TM1 controls resonance of filter 1 (QM1)
JP4: Jumper left position QM/TM1 controls resonance of filter 2 (QM2)
Jumper right position QM/TM2 controls resonance of filter 2 (QM2)
JP5: Jumper installed QM/TM2 controls type of filter 2 (TM2)
JP6: Jumper upper position QM/TM2 controls type of filter 1 (TM1)
Jumper lower position QM/TM1 controls type of filter 1 (TM1)
These are probably the most important jumper settings:
JP3 installed, JP4 right position (JP5/JP6 without jumpers):
QM/TM1 controls resonance of filter 1, QM/TM2 controls resonance of filter 2
(no filter type control)
JP5 installed, JP6 lower position (JP3/JP4 without jumpers):
QM/TM1 controls type of filter 1, QM/TM2 controls type of filter 2 (no
resonance control)
JP3 installed, JP4 left position, JP5 installed, JP6 upper position:
QM/TM1 controls resonance of filter 1 and 2, QM/TM2 controls type of filter 1
and 2