MK7 - tube mic project

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Think about it and work out the math. The wiring then will be very clear. Hint it is part of the beauty of a 47
 
Yes, I see the bias from the heater, I think the best part of the 47 is the low impedance from the vf14 tube. The ef86 is higher.
Also the pin 2 and seven is above ground . I like to ground them
 
[quote author="Gus"]No cap to ground at the 100K and 20K node in the plate/anode leg?
FWIW I have a circuit I like in one of my nady 1050 bodys and the linked microphone looks like a 1050.[/quote]

the 1µF cap is there, close to the voltage divider.
1050 looks similar to my housing - mine has the grille dome flat.

[quote author="RedNoise"]Would these fit in a G7 mic body???[/quote]
yes, if the g7 pcb fits in, the MK7 will for sure.

[quote author="jackies"]I look in my drawer, and it's not available... [/quote]
:wink:

i posted the checklist so people get the idea about what is needed. you propably need to buy a few tubes to find a silent one.
you will definately need a good capsule to beginn with. i highly recommend to use a very good quality m7 or k47 type.
regarding the tube type, i give clear recommodations for this project, but of course you can fit in anything and try everything - this is DIY after all. just dont expect it to sound as i intended if you use a different tube/capsule/transformer.
[quote author="lewilson"]Why not pin 2 and 7 to ground?[/quote]
it´s only 3,9 ohm from ground :wink:
 
hi max,
i'm in for one of those MK7 PCB sets and transformers (price dependent).
they look fabulous and i'm glad Gus has given it a good look over as well (can't go wrong with that...except maybe taking out a layer of mesh :razz: ).
very cool project.
cheers!
-grant
 
it´s only 3,9 ohm from ground ,
yes I see. and I see the cathode is also 3.9r from ground. I will try a test and compare it to a u67 type bias and see if I can here the difference. Thanks
 
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