Do you love analog synthesis? Great, let’s nerd out on Control Voltage for a bit. CV is essentially the analog equivalent and predecessor to MIDI. It’s a tried and true method used to control and interact with analog synths, drum machines, and sequencers. CV has been around for quite some time, having been implemented in the earliest modular synths. It’s an old-school technology, but a rock-solid one in terms of it’s timing and implementation.
So into this dusty old corner of synth history comes bleeding-edge UK software developers Expert Sleepers with Silent Way. This plug-in suite utilizes CV in various clever ways, allowing users to integrate analog synths with computer, DAW, and MIDI gear. There are 10 plug-ins in the suite currently, with hints on the Expert Sleepers website that there may be more in the near future. None of the plug-ins generate sounds of their own, but rather are used to communicate with external CV-based gear via your audio interface. Some spit CV out, some accept and translate CV input (which is notoriously difficult to do as the DC voltage shifts of CV are filtered out by audio interfaces, more on that below), some convert CV to MIDI or OSC events (and vice-versa). There are a number of step-sequencing feature sets available within the suite, including LFO generators and CV quantizers.
The UI of the plug-ins is fairly bland — perhaps a better description is “utilitarian”. That’s fine by me, as I consider eye-candy to be at a significantly lower cost benefit than functionality, and the UI of Silent Way functions just fine — better than most, in fact, with efficient CPU overhead and built-in support for OSC. (Hooray for TouchOSC and the iPhone — wireless control of each parameter!) Authorization is made online via a license manager (no dongle needed), and I had no issue with installation and launch of the 32-bit AU and VST versions in either the current versions of Logic or Live, running on Snow Leopard Mac systems.
Getting the cabling right between my audio interface and my analog synths was challenging, but not a dealbreaker. For this testing, I used a Metric Halo 2882+DSP output to the CV input of a couple different synths, including a Moog/Realistic Concertmate MG-1 and a Roland SH-101. The primary concern is that the interface used to spit out CV needs to be either DC-coupled or use an AC encoder bridge plug-in. Expert Sleepers recommends TRS-TS cabling between the balanced outputs of most audio interfaces and the unbalanced inputs of most synth CV or Gate inputs. The sustained voltages used for CV can potentially damage an interface if not correctly cabled. It’s super easy for audio nerds like ourselves to solder up a TRS-TS cable (or mod an existing loom), and one of the plug-ins (AC Encoder) allows for the use of non-DC coupled interfaces like my Metric Halo — however, a simple-circuit cable needs to be made for this application, adding a diode and a capacitor to the TRS-TS cable mentioned above. Expert Sleepers has numerous tutorials and resources on their site for these tech considerations. They also sell an excellent pre-wired 8-channel breakout box solution for the solder-impaired, the ES-1 module.
All nerdiness aside, the potential world of sound that Silent Way opens up is amazing. I found myself starting with simple triggers for analog drum-synth sounds, drawing MIDI notes on my DAW grid which mapped to different sounds on the SH-101. How cool is it to loop a pattern in Live while tweaking filters and resonance settings in the analog world? It’s very cool. I was also able to interface with my trusty Radio Shack Moog MG-1 for lots of trigger and LFO madness, piping the synth output back into Live for further processing. I can tell that I’ve barely begun to scratch the surface of what is possible and look forward to using my dusty synths in performance applications that were previously unavailable to me.
The toolkit Silent Way offers is vast, and despite the relative technical challenges represented by the physical interfacing of analog CV and the digital universe, it’s an incredible value. ($49 direct; ES-1 Audio/CV Interface $195-$215 depending on input & panel choices; www.expertsleepers.com)
–Dana Gumbiner, www.stationtostationrecording.com
by Walt Szalva
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