4ms Listen IO

4ms Listen IO

The Listen IO is a simple module which gets signals in and out of a Eurorack system by converting to and from normal modular levels. The top section converts any external signal to modular levels by providing up to 30x gain (+30dB), allowing you to use table-top synthesizers, keyboards, phones/tablets, computers, toys, microphones, etc. in your patches. The bottom section does the opposite: modular signals are converted to normal line level signals. The bottom two jacks can be used as line outs or as headphone jacks, so you and a friend can listen in stereo at the same time.
Each section has two inputs and outputs for use with a stereo signal or two mono signals. An LED bar graph for each output shows the signal level and clipping.

Listen IO features:

• Line to modular conversion, and modular to line/headphone conversion

• Works with guitars, table-top synths, effect pedals, keyboards, groove boxes, and many microphones

• Dual mono or stereo conversion

• LEDs show signal level and clipping

• Gain knob allows for wide range of boost or cut

• Headers in back for connecting to Listen Up or DIY adaptor module (1/4”, banana, etc.)

• Two headphone outputs and stereo inputs for use as a compact headphones module

Electrical and Mechanical Specifications

• 6HP Eurorack format module

• 0.95” (24mm) maximum depth (includes power cable)

• 10-pin Eurorack power header

• Power consumption

  • Maximum values: All output jacks shorted to ground, 22Vpp signal on all input jacks, knobs at 100%

  • +12V: 62mA

  • -12V: 55mA

• Line to Mod section (top)

  • Output: 1k impedance

  • Input: 100k impedance

  • Frequency Response: +/-0.1dB max deviation, 20Hz – 20kHz

  • Maximum output level: 22V peak-to-peak

  • Maximum gain: +30dB

• Mod to Line section (bottom)

  • Output: 68 impedance

  • Input: 100k impedance

  • Frequency Response: +/-0.1dB max deviation, 20Hz – 20kHz

  • Maximum output level: 22V peak-to-peak

  • Maximum gain: 0dB (unity)

  • Channel cross-talk:

    • Test conditions: Test signal input into left Mod In jack. Sine wave at frequencies from 20Hz to 20kHz tested. Result given as a ratio of the appearance of test frequency measured on right Line Out jack to left Line Out jack. Test repeated with left and right jacks swapped. Worst-case results for any channel and frequency reported.

    • 20Hz – 20kHz: <-110dB