4MS Listen IO
Module which gets signals in and out of a Eurorack system by converting to and from normal modular levels
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.
The 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
- Channel cross-talk:
Test conditions: Test signal input into left Line In jack. Sine wave at frequencies from 20Hz to
20kHz tested. Gain adjusted to maximum value without clipping. Result given as a ratio of the
appearance of test frequency measured on right Mod Out jack to left Mod Out jack. Test repeated
with left and right jacks swapped. Worst-case results for any channel and frequency reported. Note:
cross-talk is much higher when clipping occurs.
• @1kHz: <-110dB
• @10kHz: -78dB
• @20kHz: -74dB
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