16 step sequencer wiring?

Discussion & Documentation for Ray Wilson's synths, modules and noise boxes.
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Common Wiggler
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16 step sequencer wiring?

Post by dummyplugconspiracy »

Hi -

I'm finally deep in this build using a Soundtronics kit and circular orientation panel. Going slow and being extra careful. One question so far:

The MFOS instructions seem to tell me to connect the S0 - S15 wire leads from the digital board to both the SPDT step switches 1-16 and the rotary switch pins 1-12 (obviously omitting S0 - S03 in the case of the rotary switch). Is that simply a parallel connection and I'm just running a wire to both places from the board point? They don't seem to mean run to one switch and then on to the second one in series such that the first can engage or defeat the second. Right? Is this simply a means of giving both the step section and the controller section access to the same point on the board? I think so. Not 100% sure .....

Please confirm. I'm really gunning for zero troubleshooting on this monster. thanks!
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Re: 16 step sequencer wiring?

Post by Flounderguts »

From the MFOS website:
As explained above U5's 16 outputs go high corresponding to the current count (0 thru 15) on the outputs of U4 (QA thru QD). They are used to power the LED corresponding to the current step number. This LED lets you know which set of Coarse/Fine pots is the active one. Additionally each output (S0 thru S15) is fed to a switch and the anode of a diode which is used to control at which steps gate/trigger outputs are produced. Essentially the outputs of U5 are anded with the clock signal if the switch for a particular step is closed. I recommend using SPDT switches (even though the schematic shows SPST) to facilitate the panel wiring as shown in the panel wiring diagram. Note that both D13 and C11 are included in the panel wiring and are not shown on the PC board. All of the LEDs, switches and the diodes connected to the outputs of U5 are also part of the panel wiring.
The leds are powered from U4, the switches come off of U5.

S4-S15 on the digital board go to both the rotary selector AND the SPDT switches. S0-S3 just go to the pot panel. I ran my wires to the switches, and I just pulled a bit of insulation off without snipping the wire. I soldered that to the spdt, and ran the same wire to the rotary switch, as it was far less spaghetti this way.

When I built mine (with a variclock and a CLEE quantizer built in) I referenced the MFOS build guide all the time. I think I still have the printed sheets stuck on my cabinets for reference!

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