Doepfer A-127 BOM

In addition a breakout module A-127BOM is available. This expansion module offers the following additional functions:

• notch filter for each sub-unit
• separate outputs for lowpass, highpass, bandpass and notch for each sub-unit
• separate audio input with attenuator for each sub-unit

The breakout module allows the separate use of each of the three A-127 filters. In addition the filters can be patched parallel or serial. Especially the serial connection of three notches generates very complex phasing-like structures. For parallel filter connection the existing mixer of the main module may be used or an external mixer. For serial connection the filters are patched in the desired sequence at the breakout module. A jumper is used to define the filter type for each sub-unit for the mix unit of the main module.

Remark: The breakout module can be used without modification only in combination with the new version of the A-127 (pcb printing "Version 4"). Only the new version has the expansion connector available, that is required to connect the breakout module without soldering. It's also possible to combine the breakout module with older versions of the A-127 (versions 1, 2 and 3) but in this case soldering is required to connect the breakout module to the main module (soldering 4 wires to each filter unit). The instructions how to connect A-127BOM and A-127 main module are available here: A127BOM.pdf. This document also describes how to wire older versions of A-127 to the A-127BOM.

Note: The front panel printing of the first production series is faulty. The highpass and bandpass are mixed up. If you cannot accept this drawback we ask you to wait for the second production series (about middle of 2015).