MM3750A panel

All about it

Inspired by my concern at watching a good friend test a module by sticking a headphone plug directly into its outputs for deafening audio levels, this is a superb headphone amp in just 5HP!

It has been designed to give superb sound quality while protecting your precious phones from damaging DC voltages should a fault condition develop

It features two independent headphone monitoring circuits, each with their own stereo level control-ideal for modular teamwork, or for splitting audio to a recorder at gigs or meets.

Even better, it has a clever input normalisation scheme so that it can output:

-Two independent stereo signals 
-One mono signal sent to both outputs
-One stereo signal sent to both outputs
-An independent mono signal and a stereo signal

Tech Notes

The module uses audiophile LME49720NA op-amps and Nichicon Muse or Panasonic audio-grade output caps. Following received audio wisdom, we went with huge bipolar DC-blocking caps on the outputs rather than tiny ones on the inputs, for better fault protection. Needless to say, the level controls are quality audio-taper types!

Tech Specs

Power requirements

+12V: 40mA

-12V: 40mA

+5V: Not required


Eurorack standard, 5HP width

55mm depth below mounting rails with connected power cable 



Expected production in early-mid 2017


Watch this space