Help me identify an old German tube mic

Archived from groups: rec.audio.pro (More info?)

I recently obtained an interesting vintage tube mic that
I believe is called a Thiel M4. See photo links below.

http://retromedia.net/m4mic.JPG

http://retromedia.net/m4_a.jpg

http://retromedia.net/m4_b.jpg

It supposedly has an M7 capsule and uses an ECC83 tube.
It's very unusual in that the 220v power supply is
inside the mic body. It has 200 ohm output, but there
doesn't appear to be an output transformer.

The literature I have has the names:
Bedienungsanleitung, Elektro-Medizin, Vakuum-Technik

Does anyone know anything about this mic or point me to
someone who might? Thanks
--
--
John Noll

Archived from groups: rec.audio.pro (More info?)

playon <playonATcomcast.net> wrote:
>
>Looking at the photo of the mic, it seems a poor design to have the
>tube right next to the capsule. The heat from the tube might cause
>some problems.

If it isn't a PVC diaphragm, this is a good thing because it bakes moisture
out of the capsule and keeps it nice and warm.

When B&K went from tube to solid state electronics, their earlier solid
state mikes had resistive heaters to keep the capsules warm and reduce
problems in humid environments.

If it's a PVC diaphragm, it bakes the plasticizer out of the diaphragm
as well, which is very bad.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."