MXL 960 Tube Mic Mods?

[synthetic]

I took some photos of my MXL 960 tube microphone. From what I understand, the inside of this mic is identical to the V69 ? it's only the outside that changed. I believe you can only buy this model through Musicians Friend or GC.

Would any of the MXL mods that people have done work on this mic? I'd love to upgrade some of the caps and really bring it to life. It already sounds pretty good to me. The circuit board is all through-hole construction and there's a ton of room inside the shell, so it should be much easier to work on than most other mics. And it's only $250, so I won't cry too much if I really screw it up. I might even be able to get my hands on the schematics...

http://www.jefflaity.com/gallery/mxl960

Let me know what you think, -jl

 

[Gus]

is that a 55pf cap soldered to the tube socket? I can not read it.

is the top right transistor a fet? like a 170?

are the two transistors next to each other PNPs

The caps on the right look like panasonics electros.

I keep wondering if this MXL circuit is based off the schoeps tube microphone?

 

[synthetic]

[quote author="Gus"]is that a 55pf cap soldered to the tube socket? I can not read it.[/quote]

Labeled "56J TKV u2"

is the top right transistor a fet? like a 170?

labeled "K170"

are the two transistors next to each other PNPs

The caps on the right look like panasonics electros.

I keep wondering if this MXL circuit is based off the schoeps tube microphone?

I would assume U47 or U67.

 

[Gus]

About the only thing to do is to change the 56pf to a different cap try a CD silver mica or a polystyrene if you can find one at >200VDC. IIRC my 69 has a 200VDC B+. I changed it in my V69s not much difference

not much to do with this circuit with mods IMO

The 56pf is the feedback network from the plate to grid if it is built like a V69

This circuit is nothing like a u47 or u67. It has a tube that it might not even need, I might remove the tube in one of mine and change the front end a little

Does the tube have both halfs wired in parallel? Grid to grid, plate to plate and cathode to cathode. It might be a charge amp anode follower circuit like the v67. The tube and capsule form a circuit with a gain of about -1. this then feeds the fet.

go to neumann web site then the infopool section find the PDF book Microphones

This is the microphone I wonder if it was inspired by.

http://www.schoeps.de/E-2004/m222.html

Some solid state china microphones use a circuit like the Schoeps so am guessing this could be something else to copy, the tube Schoeps.

I have not heard or seen the Schoeps but both Schoeps and MXL are transfomerless and use a tube. The transformerless output would mean the tube part can't have much more than a gain of 1 with a standard Schoeps output