Neumann Gefell M582 DIY PSU

[Falk]

Good morning, I just wanted to briefly document a solution I tried for two microphones I was given from a friend. He pulled them out of a trashbin at a theater he was working at. I sent the microphones to a complete overhaul to Andreas Stenzel. The mics came back in great shape. Totally recommend his work.

Anyway. I didnt get a power supply with the friends gift and didnt want to spend much on this as I have enough mics in the locker and they were just an add on.

I bought this PSU at Thomann:
https://www.thomann.de/de/the_t.bone_psu_retro_tube_ii.htm
It delivers:
150V/10MA
+6.3V/300MA

Mic needs:
120V/0.7MA
+5.8V/150MA

This PSU matches exactly this schematic:

I changed D5 and D6 to 60V Zeners to have 120V for the EC92.
Then I cut the trace between L7806 and C10 and reconnected it with a 4r resitor.

I used this cable and a NS84 connector to connect the PSU and the microphone.
https://www.thomann.de/de/the_t.bone_xlr_7_pin_cable_10m.htmI disconnected the pin with the variable voltage.



Here is the mic schematic with pinout:


It works great and costs 120€ per channel.



Enjoy your PSU!
Best,
Falk

 

[ElSmurf]

A question I haven't found an answer to regarding this specific PSU : does it use the same transformer as the Apex 460/ T-bone SCT 2000 PSU? Does it have the same 200V and 9.5V secondaries?

 

[Falk]

Its 175V and 9.5V secondaries.

 

[ElSmurf]

Thanks for the pic, just what I needed to know!