Sunday, December 19, 2010

Modifications I : A-156 Quantizer Follow

A-156 with modification
Yesterday i picked up the spare parts that i ordered from Doepfer; a few switches, 3.5 mm sockets, LEDs and blindplates of different types and sizes. Now that i have them i couldn't wait to start with my first project.

One of my personal little annoyances that i have with the A-100 system are the tiny internal jumpers inside of some modules. Behind these jumpers are sometimes great functions that make these modules a lot more flexible.
Where i can, i will try to replace the internal jumpers with switches on the front on more modules, but i started with the A-156 Dual Quantizer Module.

A-156 after removing all the knobs
and frontplate
This module has two separate Quantizers, one that only uses a semitone-scale and Quantizer 2 that has much more options like minor/major/chord/quint/6th and 7th scales. There is a way to let Quantizer 1 follow Quantizer number 2 by replacing an internal jumper, but why there? It is probably a cost-saving thing from Doepfer's side but there is enough room on the frontplate of the module to place a switch with the same function. You can find a neat step-by-step guide with pictures on how to do this HERE , but it is quite easy.

Wiring the new switch
After removing the frontplate and drilling a hole for the new switch ( there is enough room above or under the printed 'Options Quantizer 2' text ) i could fit a new Doepfer 1-0-1 (on-off-on) switch in the hole and mount it back together again.

A-156 detail close-up
The wiring was quite simple, so even with my mediocre soldering-skills this was a piece of cake for me. The result is a simple and invisible modification that works perfect. Switch down couples the 2 quantizers, switch up puts quantizer 1 in it's original mode.

Okay... a similar result can be obtained with the use of an extra multiplier, but i found this one more adventurous... and rackspace-saving.
Now its time to experiment with the new options that i have. I can think of some nice patches already, but there are also some good suggestions for the use of this module and this modification at Synovatron's blog.


  1. Nice one Pierre, I may well follow your lead. Thanks for the link.

  2. @Tony My pleasure Tony. I know it is not a reversible modification but i think it is worth doing, saving valuable rack-space.