ESX-4CV

4 output CV expander for ES-5 and ES-4

The ESX-4CV is an expansion module for the ES-4 or ES-5, adding four CV outputs from one expansion header.
In order to squeeze four 12 bit channels through one 8 bit connection, the channels are time-multiplexed and so effectively run at one-eighth of the audio sample rate. For example, if the audio interface/DAW is running at 48kHz, the ESX-4CV's outputs are running at 6kHz. This is still plenty fast enough for most CV purposes, except for audio-rate modulation and the very fastest envelopes. Because the outputs are still derived from the audio stream, they retain the advantages of the ES-3/4 over traditional MIDI-based interfaces, that is, rock solid timing and absence of jitter.

The outputs are hardware calibrated and so do not require the use of e.g. Silent Way's software calibration when used with standard V/octave synths/oscillators. That said, the ESX-4CV's 12 bit resolution is adequate to perform software calibration if required (e.g. to cater for misbehaving oscillators that don't track well to a standard calibration), or to support oscillators with a Hz/V response.

Specifications

• Digital inputs: connection from ES-4 or ES-5 module
• Analogue outputs: 4x 3.5mm jacks, DC-coupled
• D/A conversion: 12 bit, using high precision Analog Devices DACs
• Output voltages: ±5.33V, hardware calibrated
• Indicators: 2 LEDs per channel (+ve and -ve voltages)

The ESX-4CV requires software in order to time-multiplex the four output signals, and to encode them for the ES-4 or ES-5. Currently, the only such software is the 'ESX-4CV Combiner' plug-in, part of Expert Sleepers Silent Way, and our Max/MSP external. Silent Way is available in AudioUnit, VST & AAX formats for Mac OS X and Windows. Use of Silent Way therefore requires a compatible host application (DAW). A Silent Way licence is not included with the ESX-4CV - however, the ESX-4CV Combiner plug-in functions in a licence-free mode, so ESX-4CV users are not forced to buy Silent Way. Such users can than evaluate the rest of the Silent Way suite in demo mode.