This is one
of a number of custom modules that Moog made for the University of New
York CEMS system in 1969. Also known as the "one step sequencer".
The module
generates three controllable output voltages actuated by either push buttons or
V-trigger inputs.
My design
is derived from pictures of an original module on the modularsynthesis.com
website. The Moog PCB for this specific module has been modified to provide
negative output voltages; the assumption being that as originally designed it
generated positive voltages.
In my implemention, the output range for each potentiometer can be configured using jumpers.
PCBs are available now , panels are currently made to order.
Many of my "moog" modules need Alpha (Taiwan) SR2511 series rotary switches. My preferred supplier for these has been taydaelectronics.com even though they have a minimum order value. However they now appear to be out of stock with long lead times.
Mouser does stock compatible switches with round shafts. Round shafts are fine, just don't use "D shaft" switches with these modules or the knob won't align with the panel graphics. However all of the Mouser stock appears to be the "19R" shaft height variant, which will leave the knob very high above the panel which looks ugly.
I have located the following alternate suppliers, I have no connection to either of these:
- in the EU: www.vanallesenmeer.nl has some stock of the Alpha parts (e.g. part number 12679 for 4P3W). They won't ship outside the EU, and note that the UK is no longer in the EU!
- in the UK: switchelectronics.co.uk has compatible switches, part numbers 483323 for 4P3W (904C), 483320 for 1P12W (901A), 483321 for 2P6W (901B). These switches are "open" and don't have dust covers. If you only want one or two, it may be cheaper to purchase via their ebay shop.
- elsewhere: if ordering PCBs from me, please ask about any switches you need. I can supply those from Switch Electronics "at cost", saving you any additional shipping costs.
I've been experimenting with some 3D printed knobs and switch caps for my "Moog" modules.
First, we have switch caps for the 1125 sample-hold module. These a mini version of the Moog slide switch caps on the original, printed in white ABS.
Then, a basic "chicken head" knob to match those on Behringer modules. They are designed to be a tight push fit onto a T18 shaft - the shaft will cut its own alignment grooves into the knob when the knob is first installed. These are plain black ABS so you will need to paint your own white line and any infill.
The switch caps are currently free with a purchase of the 1125 panel, the knobs are GBP 1.00 each.
This could be considered a "cheat", as the module
is a digital interpretation of the Moog/Bode 1630 Frequency Shifter module. For ease of construction and programming I have based this on a standard Teensy 4.0 processor module together with the Teensy Audio Board. A
custom front panel PCB hosts these together with the controls and interface circuitry.
The original Moog module requires many careful adjustments, or close tolerance component selection, in order to operate successfully. I therefore thought that the digital approach was justifiable in this case.
Note that this is a "Frequency Shifter", not a "Pitch Shifter".
There are
some differences between the 1630d and the original Moog 1630:
The 1630d
includes two audio inputs; the 1630 has only has one.
There is no
dedicated “mix” output on the 1630d – the MIX output can be assigned to “OUT A”
or “OUT B” (or neither)using the “MIXTURE”
control and associated push button.
The 1630d
includes a “MIX CV” input that can control the content of the MIX output.
There is no
“ZERO” position on the SCALE switch, as this is not required for the digital version.
The switch position has been re-used to provide a 1V/octave calibration
function (CAL) for the CV inputs.
The 1630d uses digital FIR Hilbert filters instead of the (analogue) "dome" filters used in the original. At low
frequencies the digital
filters are not as flat in their phase and frequency responses as the original analogue ones.
The software contains several user configurable options to tailor the module to individual taste.
The module can be build using only though-hole components. Some of the ICs have surface mount options instead of through-hole to ease component sourcing. You will
need to be able program the Teensy module using the open source software.
