MK47 PCB tube mic kit - build thread

[Leonardo_007]

can someone build the pcb for the ps for me, please?

i've never build a circuit board and am not able to read schematics...

 

[zayance]

can someone build the pcb for the ps for me, please?

i've never build a circuit board and am not able to read schematics...

I did an order to fab the PSU PCB, i'll have extra boards, should be here soon, i'll keep posted here...

 

[Leonardo_007]

can someone build the pcb for the ps for me, please?

i've never build a circuit board and am not able to read schematics...

I did an order to fab the PSU PCB, i'll have extra boards, should be here soon, i'll keep posted here...

thanks zayance!

i'll definitely take one!

 

[wave]

can someone build the pcb for the ps for me, please?

i've never build a circuit board and am not able to read schematics...

I have to comment on this. I wanted to have a PCB for my PSU as well and I don't read schematics to save my life.
I have never etched my own board before and I thought it was going to be hard. Zayance had posted an etch file earlier in the thread and I tweaked it and made my own board. It was easier than I thought and I learned a lot from the process.
Many thanks to Zayance  for doing the leg work on that file!

Here is a shot of my board after etching before drilling and removal of the resist. I used the presensitized board with a transparency I had printed a Staples. I had never attempted any of this and it worked great on my first try. Having the etch file Zayance made really helped to understand the layout from schematic to PCB. I tweaked mine to have the test load on the board using 1K and 1.3K resistors in series with the test switch mounted on the board.

Dave

 

[zayance]

Nice  8).

For the one i sended to fab, it is a little different than my etch file..
A little longer, about 155 x 78mm, and accepts on board until 10W wirewound resistors,
And Caps  25mm Max Diameter but i ommited the 5mm pitch, and just went for 7.5mm pitch and 10mm SnapIn footprint.

Sneak pic:

 

[Songguy]

What are the dimensions of that nice PCB.
Chris

 

[zayance]

What are the dimensions of that nice PCB.
Chris

It's on my previous post, but i edited right after so maybe while you were replying..

And as for the test Load on board, as it was stated before from Kingston, it's not very useful i think, and i didn't needed that, saves space as well..., a nice big dummy load at the output connector when testing and you're done with it...

 

[wave]

What are the dimensions of that nice PCB.
Chris

It's on my previous post, but i edited right after so maybe while you were replying..

And as for the test Load on board, as it was stated before from Kingston, it's not very useful i think, and i didn't needed that, saves space as well..., a nice big dummy load at the output connector when testing and you're done with it...

I did read that whole part of the thread. The reason that I included it was mainly just to stick something on the board for practicing my schematic to board layout skills. I don't use Eagle or any PCB software, I just draw it in Illustrator 

EDIT: That's a nice PCB you got there Zayance!

Dave

 

[zayance]

What are the dimensions of that nice PCB.
Chris

It's on my previous post, but i edited right after so maybe while you were replying..

And as for the test Load on board, as it was stated before from Kingston, it's not very useful i think, and i didn't needed that, saves space as well..., a nice big dummy load at the output connector when testing and you're done with it...

I did read that whole part of the thread. The reason that I included it was mainly just to stick something on the board for practicing my schematic to board layout skills. I don't use Eagle or any PCB software, I just draw it in Illustrator 

EDIT: That's a nice PCB you got there Zayance!

Dave

I wasn't criticising your choice, but saying again why it was done so on the etching file and on this PCB as well.
And Sure whatever feets your bag of tools, actually i've seen great stuff done with illustrator, and some folks here like ti better than those "chunky" PCB programs, well that's what they were saying about it haha, but i can understand that, as Eagle is a little chnuky on some things, but anyway all programs have their pros and cons as always...
Depends on your skills and what you want to do with it also, i don't see triple layer done on illustrator, but again depends on skills...
Anyway nice job, nice thinking, and nice result, learning by doing is always better....

Thanks for the kind words, yes i like it also haha, had fun with it, there is very few components so... Zen garden style, do you hear those birds? lol.....

 

[Monoklang]

Here is a pic of my mounting I've used it twice now worked great

How deep did you dare to drill those holes? I'm about to do the same thing here, is 5mm too much?

/ John

 

[jrasia]

Hey can someone provide some quick tech support?

Finally finished my build with a Thierch M7 capsule.

Fired her up and it didn't fry

Cardioid sounds good, but when I switch to omni on the PSU I get a loud buzzing sound that stays.  I can however still hear it pass audio underneath all the buzzing.

Seem like I also need a fair amount of gain on my preamp (cardioid), about 35db on my AEA TRP preamp.  Is that normal?  I always had the impression the u47 is a very high output mic.

It is also rather warm to the touch on the body of the mic. Is that normal?  Never played with u47 before

Thanks

Jason

 

[david-p]

Cardioid sounds good, but when I switch to omni on the PSU I get a loud buzzing sound that stays.  I can however still hear it pass audio underneath all the buzzing.

Seem like I also need a fair amount of gain on my preamp (cardioid), about 35db on my AEA TRP preamp.  Is that normal?  I always had the impression the u47 is a very high output mic.

It is also rather warm to the touch on the body of the mic. Is that normal?  Never played with u47 before

Quick help, though I havent built this particular circuit.

Sounds like you have a problem with the relay, either in the power supply wiring, or in the mic.  Can you hear the contacts actually close when you put your ear up to the mike and operate the switch?  Check the wiring carefully.

I am assuming that you are using the standard PS circuit.  Do you have the dummy resistor selected in the other position?  In which case, there should definitely be no change in hum.

The resistor shown in the pic above will get warm.  This is normal for all U47s.

35dB of gain sounds OK.  The output from a U47 is comparable to most condenser mikes.

David

 

[jrasia]

Thanks for trying.  I think after more problem solving the issue must be with the mic cable I made 
With only the audio xlr cable hooked up there is no noise.  Once I attach the mic cable (GAC 7) to the PSU, but not hooked up to the microphone, the buzzing issue with omni is there and passing through the audio. I'm at least glad its not the mic( I think).

I work in IT and deal with the ID ten T errors all the time, so I feel a little silly having to resort to such questions, but I  drew a diagram of what I did with the cable(See pics). I like pictures.  They help simpletons like me.  I'm by no means an electronics wiz.

The PSU (Scott Hamptone) is wired as follows.  Pins 3 + 4 are common ground.  Shield also goes there from the connector

1. audio+
2. audio-
3. Ground
4. Ground
5. +105vdc @ 50mA
6. Pattern

I wired my cable as follows.

XLR                                  TUCHEL

1(A+) ----------------------  1(A+)
2(A-) -----------------------  2(A-)
3                  empty          3
4(B-) --------blue-----------4(B-)
5(B+) --------red -----------5(B+)
6(P) ------------------------- 6(P)
Tab -----Cable Shield--------7 --- Bridged to Tab


Then inside the microphone on the male 7 pin binder I have the shield bridged to pin 4.  Pin 4 is then bridged to the mic rail.  Though, I'd like to confirm the wiring on the cable first before looking at the male binder.

Sorry for the long winded post.  Again, any help is appreciated.

 

[G-Sun]

What size is needed to mount the pcb?
There, found it: "Assembled unit: main PCB is 86 x 44 mm"

 

[johnny dance]

Hey,

currently building with a EQu47 body and a Thiersch caplsule (very slowly)

any one have any idea on where to get a binder 691 connector for the mic cable to mic ?

I think someone only used zip tags to hold the M47 in the case... any photos?

 

[david-p]

any one have any idea on where to get a binder 691 connector for the mic cable to mic ?

www.binder.com in the USA.

David

 

[johnny dance]

thanks ! ordered a set of them...

one last question: does any one have any closeup photos of the connections of the Capsule, to the PCB? Just wanted to make sure I was doing it right, but slightly confused by the glass bits, how to solder it etc...

 

[Ishi]

I finished building MK47.

I used STC-700 for the body of the microphone. The microphone cable was created by NC7 FX-B of Neutrik XLR and Gotham.

But a connector does not separate from a microphone :'(
Is there any method of solving this?

 

[Leonardo_007]

any news on the fab psu pcb's, zayance?

 

[Volume11]

Hey guys, I am having trouble getting 48v, and 105v with the mic hooked up. The most I can get is 45v and 99.8 v with the pot turned fully clockwise. Do I need to lower a resistor value somewhere before the pot? I want to test this myself with trial and error, but I want to use the mic tomorrow, so I'd hate to mess something up before then. It works without any problems and sounds good. I read somewhere back in this thread that the incorrect voltage values could possibly lower the lifetime of the capsule, so I am a bit worried. Any advice will be greatly appreciated.
Thanks