MK47 PCB tube mic kit - build thread

[poctop]

In the case this might be of interest to anyone,  i am starting this project and would like to share this cart ,  i decided to upsclale the power supply to 10 watts and use a 50 Va for 10 dollarsextra there are some neutrik connector  in there too just check the quantity to make sure because i always grab some extra when i order at mouser.
there is also a power entry module with fuse and emi filter inside that might help here.

http://www.mouser.com:80/ProjectManager/ProjectDetail.aspx?AccessID=7078b436c0

Cheers,
Dany,

 

[wave]

In the case this might be of interest to anyone,  i am starting this project and would like to share this cart ,  i decided to upsclale the power supply to 10 watts and use a 50 Va for 10 dollarsextra there are some neutrik connector  in there too just check the quantity to make sure because i always grab some extra when i order at mouser.
there is also a power entry module with fuse and emi filter inside that might help here.

http://www.mouser.com:80/ProjectManager/ProjectDetail.aspx?AccessID=7078b436c0

Cheers,
Dany,

Thanks for sharing!
With this power transformer what resistor values need to be swapped to get the same 105v as on the original schematic?

 

[poctop]

I think it is the 330-680  swapped for a single 1.5 K as per kingston , 
Cheers ,
Dan,

 

[JamesW]

Here is #2 works great

 

[JamesW]

PSU gut shot

 

[wave]

PSU gut shot

Looks great! Congrats!

I have a couple questions:
How did you create your psu board?
What kind of transformer is in there?
How did you get your logo on the psu panel?

Cheers!
Wave

 

[JamesW]

the board is done P-T-P with eyelets just like fender amps

the transformer is Antek AN-05t200

the logo is water slip decal done with inkjet

 

[david-p]

James (W):

Where did you get the box for the power supply?

I am intrigued by the two vacuum tubes... Do you dispense with an output transformer?  Is the circuit posted anywhere?

If these details are given in the preceding 28 pages and I have missed them, please let me know; otherwise, answers would be appreciated.

Many thanks,

David

 

[SKJGProject]

eeeeehhhhm, did you check the very first post???? ioaudios mk47 pcb is the thing in the pic and what people were talking about the whole 28 pages 

 

[david-p]

eeeeehhhhm, did you check the very first post???? ioaudios mk47 pcb is the thing in the pic and what people were talking about the whole 28 pages 

Thanks for pointing this out: I hadnt realized that there are two 29-page threads on the same subject, and that this one is different from the other -- which I had read completely!

However, while there are two valves on the pcb, there is only one in the circuit diagram on the first page.

Also, I cant find any details for the PSU box.

David

 

[JamesW]

[/quote]



Also, I cant find any details for the PSU box.

David

[/quote]

This PSU box is a copy of the first box I purchased from Grand Master Audio. The main part Hammond #cwsc424nk and cwcp4. This is not a quick and easy solution but it does look like the original.

 

[Skylar]

eeeeehhhhm, did you check the very first post???? ioaudios mk47 pcb is the thing in the pic and what people were talking about the whole 28 pages 

Thanks for pointing this out: I hadnt realized that there are two 29-page threads on the same subject, and that this one is different from the other -- which I had read completely!

However, while there are two valves on the pcb, there is only one in the circuit diagram on the first page.

The two threads are two entirely different mics, both by ioaudio.

This thread covers the MK47, whereas the other thread covers the MK7.

The schematic on the front page of this thread shows a "tube" that ioaudio calls the "VF14r." There is no such tube—it's simply a moniker for two 6028 tubes in parallel, which approximates the operating conditions of the orginal U47 tube, the ridiculously rare and expensive VF14M. Using this arrangement allows you to keep the rest of the parts identical to the U47's circuit in the hope of replicating said mic's sound.

 

[david-p]

The plot thickens.  The thread Skylar refers to is actually a new one to me.

I was referring to http://www.groupdiy.com/index.php?topic=35667.0



David

 

[Skylar]

The plot thickens.  The thread Skylar refers to is actually a new one to me.

I was referring to http://www.groupdiy.com/index.php?topic=35667.0



David

ahhhh, I think that was just the feeler/announcement thread. That might have been made before the White Market existed.

 

[wave]

James,
I forgot to ask what capsule you went with? Also, what did you source for a body?

 

[JamesW]

James,
I forgot to ask what capsule you went with? Also, what did you source for a body?

Look at the post above yours that handsome Dude will sell you both. I purchased both my BeesNeez capsules on the blackmarket.

 

[wave]

James,
I forgot to ask what capsule you went with? Also, what did you source for a body?

Look at the post above yours that handsome Dude will sell you both. I purchased both my BeesNeez capsules on the blackmarket.

Oh Ive been on the Equinox website quite a few times! I was just wondering what you used 

Thanks

 

[mrcase]

hey!

unfortunately my mic stopped working :-( was working great for a few months then suddendly I got a higher noise level then checked the wiring and it stopped working completely.  :'(
It was always sensitive if I moved mic cable, producing crackles and stuff.
One thing I was wondering.
Where do you connect the screen of the tubemic cable to? do you connect it to XLR1 and to the mic case?
where did you put it in the miccase? (before I didnt connect it to the mic case, but now I think I should?)

here is how I did my mic cable:

1 A+
2 A-
3 B-
4 -
C Screen ??
5 B+
6 Pattern


thanks for your help!
martin

 

[mrcase]

ok. one strange thing. I got continuity between A+ and A- on the pcb? thats not normal is it?
Please help!!!!!!!

 

[Majestic12]

A+ and A- are the transformers secondary side it's a normal thing to have low resistance here....