Sennheiser ek100 1G IEM Amp Mod

Thomas Petrusky

Freshman
Mar 15, 2012
64
0
6
Ok so after someone nicked my receiver I figured I wanted to have a go at converting an EK100 into a IEM receiver with amplified output sound rather than the line/mic level out that the body-pack receiver originally put out.

This is a two watt amplifier chip and is driven from any input form 4.5v to 19v so it can run off of the internal battery. I found the initial power stage one the unit to tie the unit into but to avoid overloading the factory circuitry. To run the amp I had it trigger a pair of transistors as the whole output and input stage is common bonded with the amp and receiver. Original gain knob controls the level fed into the amp circuit and I rotated the output 3.5mm jack and just sent the output to both L&R. Mono is ok since I only use it for my personal iems while running stagemix's cue to my ears when running monitors from the ipad.

I checked the power draw before and after the install and I went from 70ma to 73ma draw when powering my in ears as hard as I could stand them. The quality is as good as the old receiver pack meant for this job and was a nice compromise squeezing the extra hardware in rather than spending hundreds on a new pack.

iem0.jpg
iem1.jpg