Product Update - 904C Filter Coupler

While assisting a customer in debugging his 904C build, I have discovered that the connections to the left "Frequency CV" socket and the "Bandwidth CV" socket are reversed on the PCB.

The latest version of the build document (V1-2) includes instructions for correcting this on already built modules.

Grey Panels

After some experimentation by my very helpful panel supplier, I can now offer any of my panels in GREY for a close match to Behringer System 100. They are not a perfect match as the Behringer panels are powder coated, but mine are anodised.

Grey panels are manufactured to order, I do not intend to keep these in stock.

Selelection of grey panels

The panel second from the right is the best match in studio lighting conditions.

Software moving to Github

I'm moving software downloads from dropbox (linked from this site) to Github.

 

I've started with the Ardiuno sketch for the 1630d frequency shifter.

 

Other software on this site will follow gradually, and any new software will be available via  Github only.

 

Triggered Controller

 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.

Rotary Switch Availability

 

 

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.

 

 

 

901B PCB Restock

 I've restocked with PCBs for the 901B Oscillator module, and for the Universal Daughter Board (UDB) used in the 904C PCB set.

 

 

1630d BOM errors

 It's come to my attention that there are a couple of errors in the BOM for the 1630d Frequency Shifter,  however the schematic values are correct.

R17 and R22 are 33K

R16 and R21 are 200K

In combination with the 100k CV input resistors, these values will scale a 10V CV range (+/- 5V ) onto the 3V3 range that the Teensy ADC uses.

1630d Build Doc version 1-3 corrects this error.