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