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Voltage on plate in tube mic?

Posted: Sat May 03, 2014 9:47 am
by JJ2013
Hi y'all AudioPhiles and VooooooDoooooo Gurus!

I recently purchased an MXL V69 ME tube mic and replaced the tube with a really nice 12AT7 (below, what the seller communicated) and it did make a difference to the audio, it is now more detailed.

" This 6201 / CV4024 / E81CC gold pin tubes were made by Valvo in Western Germany and are were relabeled by Amperex!

- This is a "New Old Stock" (NOS,) Hamburg, Germany factory tube that is sometimes marked or made for "Phillips," "Amperex," "Valvo," and sometimes "R/T!" It is a VERY RARE tube and thay all have early 1960's date codes on them! These are Military spec. tubes with gold pins...These excellent tube that is very similar to the "Telefunken ECC801S" in build quality!"

I seem to recall having read somewhere that depending on the original voltage changing the tube won't do much although I have in some postings that it did.

QUESTION: Now, does anyone know what the voltage on the plate of the tube in the V69 is? Voltage on the stock tube? I will also email MXL for that information.



Posted: Mon May 05, 2014 1:51 am
by Voodoo Guru
Howdy JJ,

Tube rolling is fun!! :D

The schematic for the V69 seems to be unobtainium, but we did come across a post of a guy that measured the voltage at 200VDC.

Third post down the thread.


Posted: Mon May 05, 2014 7:30 am
by JJ2013
Hey VooDoo Guru :)

Sure appreciate your response as always

At least they are not starving the tube for voltage then :!: :!: