M7 + BV8 open to suggestions

[zamproject]

Hi all

Long time I don't play with mic build.
I have two MK47 with thiersh M7 and IOaudio BV8 in Equinox bodies, I also should have a Dale M7 laying around.

I build two at that time...because you always expect stereo use at some point. But in 10 years i think I only use this setup once...
Also due to S/N those mic are way far from my go to vocal mic, despite the great sound and character going out of them.

I'm ready to do something else with one of them, keeping expensive part, trafo and capsule
What are you guys suggesting if I want to keep the BV8, regarding drive/load etc
Can a fet substitution of the tubes be done ? is the schemo laying around effective ? in this case hoping a "silent" mic
There is also the idea of a G7, I like the idea of the multipatern (especially 8 figure, I don't have true -large- condenser with fig 8)
Any other idea welcome !

Best
Zam

 

[Recording Engineer]

Hmm… I’m thinking Phaedrus solid-state direction or the UM57/UM75/M990 direction.

 

[zamproject]

Tks, I'll look at that !

 

[zamproject]

So basically the difference between UM57 and 75 is the tube...single triode or pentode wired as triod.
That a good option with multipatern. I'll see how I can adapt my single 105V PSU, the trafo have a 6.3 (now just for pilot light)
Should be doable with small investment

Best
Zam

 

[Recording Engineer]

Yes, the UM75 is suppose to be pretty much a reissue of the UM57. The M990 is pretty much suppose to be a “modernized”/“upgraded” version. …All from my perspective, with what I can tell.

 

[LevinGuitar]

I really like the "sound" of the EF14 tube with FAB BV8 (and for now a cheap chinese k67) in my U47 experiments. Still have to improove gain and noise, but guess it will worth the effort.

 

[Purplenoise]

You could make a point to point 47. My personal favorite is with a 13cw4 and different bias ( a parallel 27ohm to the 68ohm resistor in Neumann schematic). The schematic is easy to find ( official Neumann).
Dead quiet and closer to original u47 than ef800, 408, ef12 etc

 

[zamproject]

ha yes nuvistor, I forget this.
I just have a quick look, seem not that easy to catch...

 

[zamproject]

cross topic quote

EF42 is great as microphone front-end - if tube microphonics dosen't scare you, they're always microphonic..

To my ears, the EF42 is the one sounding closest to VF14, when underheated and in G7 setup.

However, that tube has massive problems with microphonics.

Jakob E.

Ok, I want to try this as I just catch two EF42 !

@gyraf
Any recommendation about heater/cathode voltage in a U47 setup ?

Cheers
Zam

 

[gyraf]

When we tried a verybig-bunch of different tubes, we just plugged them into standard G7 circuit..

 

[zamproject]

When we tried a verybig-bunch of different tubes, we just plugged them into standard G7 circuit..

so a separate heater

I suppose I'll wire it as standard U47 circuit (what I have here) and see what happen (with variac) then tweak heater/cathode series resistors if needed.
EF42 ask less heater current so I suppose higher filament resistance, so it will lower cathode bias ?