MK-U47

[Tungstengruvsten]

I'm in for one to complete my EQU47...but I have the same concern about the tubes.  Is it possible to aquire a spare set?  Or at least know what specs need to be met to purchase a proper pair?  Don't think i'm gonna buy a VF14 as a backup...

 

[fazeka]

I'm in for two (email sent)

 

[bobine]

email sent for 1 kit

thanks!

 

[ioaudio]

Re: tube
as posted (and pictured), miniature pentodes are used, the type will be revealed as soon as you receive your order, so you can buy them in the open market, aditionally i can offer tested pairs.

-max

 

[mad.ax]

Email sent...
Congrats for a very clever design... I guess those two triode strapped pentodes are wired in // but their heaters are in serie...
So simple, so obvious, such an elegant solution...but AFAIK, you are the first one to implement it for a VF14 substitute!
Well done! I can't wait to try your kit.

Axel

 

[ltronsm]

Email sent for two kits

 

[synthi]

Max, do you have a good design for the PSU? something with very low noise and reliable? Thats something we can build in advance...

Thanks!

 

[ioaudio]

could be simple as that (like U47 NG PSU)
Disclaimer - High Voltage - build and use on your own responsibility

 

[suli]

HI


I'm in for one! Emailed.

Thanx

 

[milesjackson]

Email sent...
Congrats for a very clever design... I guess those two triode strapped pentodes are wired in // but their heaters are in serie...
So simple, so obvious, such an elegant solution...but AFAIK, you are the first one to implement it for a VF14 substitute!
Well done! I can't wait to try your kit.

Axel

Actually, Oliver Archut suggested the same idea a few years ago with a WE 407a tube.  It's a dual triode with a 40v heater in series, so you could theoretically make it work in the U47 circuit.  Oliver thinks that the tube is too noisy for a decent tube mic, but maybe ioaudio's got some tricks up his sleeve.

 

[Junction]

email sent for 2

 

[buschfsu]

io how would you compare the mk7 to the mk47.  i was going to use the one i already have (mk7) in skylars mic body.  is there a large difference.

 

[Brolik]

1 kit please if still available. This looks awesome.

 

[12volts]

I would like to add my name to the list of pre-orders. 1 kit for definite.


Frank

 

[mad.ax]

Email sent...
Congrats for a very clever design... I guess those two triode strapped pentodes are wired in // but their heaters are in serie...
So simple, so obvious, such an elegant solution...but AFAIK, you are the first one to implement it for a VF14 substitute!
Well done! I can't wait to try your kit.

Axel

Actually, Oliver Archut suggested the same idea a few years ago with a WE 407a tube.  It's a dual triode with a 40v heater in series, so you could theoretically make it work in the U47 circuit.  Oliver thinks that the tube is too noisy for a decent tube mic, but maybe ioaudio's got some tricks up his sleeve.

Wiring heaters in serie is not new indeed. We407A has been tried as a VF14 substitute, but without much success, as its triodes, even paralleled, doesn't behave like a triode strapped VF14.
Paralleling triodes in order to lower the plate impedance is not a new idea either, but so far I only saw it implemented with dual triode in one bulb.
Using two tubes in a mic has been done too, but in a multi stages configuration.
My understanding is that Max took two individual pentodes, triode strapped them, paralleled them , and then wired their heaters in serie, and that, I believe, is a first in a tube microphone.

Axel

 

[Matthew Jacobs]

Couldn't resist....

Ordered 2 kits

Email sent

JD

 

[mrcase]

I take one!
email sent!

can´t wait!  ;D

 

[Jim50hertz]

Two kits please, emailed this morning

best regards

Jim

 

[Matthew Jacobs]

The relay for switching the pattern is an excellent idea....

 

[mrclunk]

Arrr... i really want one but think i'll have to wait for the next batch... Too skint. Looks fantastic though!