Euro and Buchla working together

Here's a short video by Eldancer showing the buchla and Euro systems workng together. Both the CVGT1 and a custom euro Buchla interface module I made a while back are in use here (top right hand corner). They don't get the limelight, they just allow the conversation to occur, working quitely in the background :)



mutipatch 1 from Eldancer on Vimeo.

A quick update on CVGT1 Modules

About half of my pre-order list for CVGT1 modules have been delivered and the rest will go out within the next month. Within a couple of months they will appear with distributers but I am having to look at relaying the boards for surface mount to keep assembly costs down - I don't want the price to go up and I cannot keep building them myself - after building 60 CV Tools and 20 CVGT1 modules (220 circuit boards in all) I am all soldered out. CV Tools will also get relaid for surface mount but I will still keep a through hole stock (currently sold out) for DIY kits.  Watch out for my next update in a month.

Announcing Synovatron's second module CVGT1

Sneak preview

The new module is a Eurorack format Eurorack/Buchla translator called CVGT1. It allows Eurorack and Buchla synths to interact with each other, as the name suggest it provides a CV and a Gate/Trigger interface. Not only does it provide the correct format connectors (and adheres to the Buchla color code) but it also deals with the CV scaling and offsetting and the gate/trigger and timing pulse conversion required to allow control in both directions.

The module is in final stages of build and will need to undergo design proving tests before I release it into the world. So far the front panels are complete and all the components are in stock except for the slightly important PCBs which are due in tomorrow (18th July 2012). The intended launch date is Saturday 21st July at the Brighton Modular Meet at the University of Sussex just outside Brighton UK. 

Here are some quick photos of the panels and partial assembly.  I will follow up in a few days with better photos of the fully assembled module, further details and User Manual download link.

1200HP Monster Synth

I met with Gregg Wilson at the last Brighton Modular Meet. We had talked about the possibilities of this project prior to the meet as he had bought a CV Tools from me. Anyway I ended up building the power supply and Trunk-line modules for his brainchild 1200HP wall mounted synth over the ensuing months so thanks Gregg for placing your trust in me. It is not only amazing as an instrument but also also as a visual feast - a fine piece of active wall art - well conceived and nicely built. The surrounding backlighting sets it off a treat.

The fantastic Wenge wood case was made and installed by Ross Lamond of Lamond Design; This guy rocks!.

Here are a couple of videos of what any synth does best - being used! Enjoy.



Modular Synth Live Performance 1 from Gregg Wilson on Vimeo.

Modular Synth Live Performance 2 from Gregg Wilson on Vimeo.

I Dream of Wires 2: A documentary

A very inspirational video; certainly from my perspective as a small manufacturer of synth modules. Modcan's Bruce Duncan and Intellijel's Danjel Van Tijn give the low-down on their synth building ethos. I have huge respect for these guys for their achievements, products and thinking. Check this out. 

Euro to Buchla CV Interface Module

I was commissioned by a client to design and build an interface module that allowed his Euro synth to modulate his Buchla synth and vice-versa.

Format Jumbler?

Euro uses 3.5mm mini jack sockets and Buchla uses 4mm banana sockets (which are colour coded). However this design is not just a 'format jumbler' because aside from the connector differences the signal ranges are different.  Buchla uses CV signals in the range of 0V to +10V and Euro uses nominally ±5V (well actually anywhere between -11ish Volts to +11ish Volts).  My client wanted 4 channels of Euro to Buchla and 1 channel of Buchla to Euro. 

Design Spec

The design spec I settled on was ±5V in (Euro) gives 0V to +10V out (Buchla) on channels 1 to 4 and 0V to +10V in (Buchla) gives ±5V out (Euro) on channel 5. As you can see the inputs and outputs both have 10V swings and so a gain of 1 is required but with a 5V offset (-5V one way and +5V the other). The input impedance of 100k and output impedance of 1k was used as it's fairly standard.  I used clamping diodes on the Buchla outputs so that an input more negative than -5V didn't cause a negative output to the Buchla. Because there might not be a common ground reference between the two synths a GND socket was also added to the design. Note that Buchla colour coding uses black for CV outputs and ground connections, blue for CV inputs.

Implementation

As the job was for just one module I used one of my standard 8HP front panels (order code 8HPP) and a new DIY prototyping PCB (order code DIY3) to build the design onto. 

The 8HPP front panel has 10 3mm pilot holes which had to be opened out to fit the 4mm and 3.5mm sockets plus a new hole for the GND socket. I settled on the position for the GND socket equidistant between the four lowest connectors really just for best spacing; I looked at putting it below the lowest two connectors but decided (incorrectly) that there would be not enough space to get fingers in and also avoid the mounting rail.

8HPJ (left) and 8HPP (right) Front Panels

The DIY3 is a bigger version of the DIY2 prototyping board and allows more complex circuitry to be realised due to the larger breadboarding area, power rail support for op-amps and A-100 Bus support (it is effectively a hybrid between DIY1 and DIY2 boards). The idea behind DIY3 was to be able to do more with jack-socket only designs such as buffered mults and attenuators, amplifiers, logic and gate/trigger circuits etc.

DIY3 Prototyping Board

The First Module

Here is the first module which I'm pleased with. It showcases the DIY prototyping board's capability nicely. The client was happy too.

The Second Module

On the back of the first order another client expressed an interest in the same functionality but preferred the GND socket to go below the lower two connectors. There was enough room to clear the mounting rail but pushes it closer to the channel 5 connectors than is ideal but still looks ok.

Further Modules?

I have another two expressions of interest for these modules especially if they were production rather than prototype versions. One suggestion was for front panel graphics to be added using the same font/style as Buchla which I like the idea of. Another thought is that not just CV translation is useful, gate/trigger translation would be useful too (as they are not compatible between the two 'standards'). I could also provide these as very basic kits (all the bits you need, a circuit diagram and a layout pattern). If I can get a few more interested parties to make it viable I would consider a small production run with purpose designed PCBs and a screen printed front panel. So if there is any interest out there please make your thoughts known to me.

Trunk-line Module

I was commissioned by a client to make some Trunk-line Modules. These are similar to the Analogue Systems RS-250 module but offer rear facing jack sockets instead of unterminated jacks that you have to solder wires to and is ideal if soldering is not your thing.

8HP 10-channel Trunk-line Module front jacks

8HP 10-channel Trunk-line Module rear jacks

The point of a Trunk-line module is to provide front panel access to either outboard equipment such as mixers, sound cards, MIDI/CV units etc., or to provide connection across a very large synth (using two modules) so you don't have to use very long patch cables on the front panel. Most of us don't have big enough synths to warrant this so these really are for large synths that are more like installations.

The photos show an 8HP 10-channel module; I have made a few of these modules to order and because of the small quantities involved there are no screen-printed markings (due to the setup costs). I'd like to know if anyone else would be interested in a Trunk-line module and, if there were large enough numbers, I'd do a small production run with screen printed markings, so please let me know; I could also do a 4HP 5-channel version and versions with solderable sockets too.