Dual quad sequential switch

This module is really useful for switching between sequencer channels. It is based on Doepfer A-151, see Doepfers website here, first edition but with some changes. It has trigger and reset inputs, four in / outputs and a common out / in. I've added a step length switch, switching between 2, 3 and 4 steps. I've made two sequential switches in the same module, using switching jacks to make the second one slave to the first one (i.e. they use the same trigger and reset inputs, but individual step switches), or they can act independent of each other. Like the Doepfer version 1, this module only works with signals between -8V and +8V.

Unfortunately there are no building instructions for this module, but at least you'll find the schematic, some photos, and some comments.

  1. I played around with different LED colors, and if you do that you probably need to consider R11-R14 values to find the right light levels for the LEDs. I used 1k for yellow LEDs (3500mcd), 2.2k for red LEDs (3500mcd), 220 ohms green LEDs (3500mcd), 6.8k for blue LEDs (2100mcd), and 7.5k for white LEDs (5800mcd).

  2. Unfortunately I couldn't find diffuse blue or white LEDs, however with some fine sandpaper it is easy to grind the glass around the diode and make a diffuse LED.

  3. The finished module, but without the front panel.

  4. The finished module, about to be mounted.

That's it! Have fun and switch your sequencer channels!


Updated - 2013-12-26 18:11
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