Rens Heijnis                                      custom-built audio equipment

B&K  DPANeumannSchoeps  AKG



Improve the sound of your Schoeps microphone by retrofitting and separated power supply.

When you are not satisfied with the sound of your Schoeps microphone such as the CMC 5 or 6: too muddy,
lacking vibrancy and detail.or anything else, it is possible to retrofit your microphone with optimized electronics
to improve the sound.
After retrofitting your microphone has a tighter low, more vibrancy detail and high frequency.
At the former
microphones page you can read the theory about retrofitting:

A retrofitted microphone has a new printed circuit board with trough-hole components.
All the components are selected for there proven sound quality.


Power Supply for active powered Schoeps microphones

Technical Specifications PS-402
Number of channels: 2
Input: 4-pin XLR female connector
Output: 3-pin XLR male connector
Power requirements: 105-120V and 210-240V, 50 to 60 Hz
Power consumption max: 3W
Weight: 1 kg
Dimensions: 108mm × 165mm × 52mm (4.3” x 6.5” x 2.1”)


Microphone Cable for active powered microphones

A special microphone cable is necessary between the microphone and power supply.
The standard microphone cable is a Mogami starquad cable:
Mogami 2534
For the +60V norm it is supplied with 4 pin XLR connectors.
Every cable length is available.
The output of the power supply is a normal 3 pin XLR.


Retrofitted CMC-6 with active power


This modern Schoeps CMC6 version also has a poor sounding SMD printed circuit board.
After retrofitting the Schoeps microphone, the complete PCB will be replaced for a
PCB with components proven for the sound quality and a through hole setup.


Battery powered pre-amplifier for active powered Schoeps microphones

4 channel pre-amplifier with Lithium ion batteries and the latest developments in improved sound quality.
Light weight: 3,3kg. Dimensions: 28cm × 25cm × 10cm
Input: 6 pin XLR for active powered microphones.
Recording time 30 hours including microphones power.


Sonodore MPB-502


Pre-amplifier for standard B&K /DPA Microdot and active powered Schoeps microphones

Special light weight (2,9kg) 3 channel pre-amplifier with Lithium ion batteries and the latest developments in improved
sound quality.
With DPA MircoDot (4060serie) and active (6pin) microphone input. With battery power for the microphones.
Recording time 34 hours with active microphones, 43 hours with only DPA MicroDot.
Back view

 Audio samples

Direct comparison standard and retrofitted Schoeps, 7 different audio samples. 
Retrofitted 24bits 96KHz zip  Audio sample A

Standard 24bits 96KHz zip   
Audio sample B
Equipment: Schoeps CMC6, Preamp Forssell SMP-2, AD Forssell MADA-2.
ade by Ivo Sedlacek,

interesting comparison between retrofitted Schoeps and normal DPA4006
Retrofitted Schoeps CMC6, 4 channel version MPB-502, van den Hul integration hybrid cable, sounddevices 788t
88,2 kHz  Audio sample 24bits     Audio sample 16bits  
Standard DPA4006 48V,Vovox sonorus direct cable, sounddevices 788t
88,2 kHz  Audio sample 24bits      Audio sample 16bits  


Reference on the retrofitted Schoeps CMC6 microphone with an active 60V PCB. 

Branic Howard, Open Field Recording:
Your updated Schoeps sound fantastic to my ears.
The retrofitted mic body circuit provides a different lens on what the Schoeps capsule hears.
For me, the most important change is the transient clarity—such beautifully rendered percussive sounds—
I hear a more relaxed and 3D sound stage.
They also have a very well articulated bass. I am excited to use them for years to come!