MK47 PCB tube mic kit - build thread

[Dazazone]

Hey max I tried to email u last week about grabbing one of the kits before they all go. Did you get my email ok?  Would love to do this project

 

[Jim50hertz]

- unsure how the polar pattern switch works, what are you guys using, normal SPDT?
I'm using a Lorlin.

Must you use a switch?
Or can you wire direct?

The switch changes the polar pattern from cardioid to omni.  One could hardwire if one wanted only one polar pattern, i.e. cardioid only.

Or am I misunderstanding your question?

 

[Le Roux]

The switch changes the polar pattern from cardioid to omni.  One could hardwire if one wanted only one polar pattern, i.e. cardioid only.

Or am I misunderstanding your question?

So the switch is merely an on/off for 48V, switching from cardioid to omni?
Sorry, new at mic building...

 

[mad.ax]

The switch is indeed used to on/off the relay that does the select the pattern.

But that makes me think that we could use the phantom power to remote the pattern change...

Max, what are the coil's characteristics and power consumption of the the HighZ relay?

Even if it cannot be powered directly by phantom power, adding a transistor and a relay instead of a switch inside the PSU could be doable...

Axel

 

[Winetree]

OK,
Just got my Skylar Mic Bodies and went back to the first page for assembly.
The body is different in the examples. Where are the brackets to mount the P.S.B in the rails?.
Do I still mount the white risistor to the base and extend the wires or let it hang
there's plenty of room.

 

[living sounds]

OK,
Just got my Skylar Mic Bodies and went back to the first page for assembly.
The body is different in the examples. Where are the brackets to mount the P.S.B in the rails?.
Do I still mount the white risistor to the base and extend the wires or let it hang
there's plenty of room.

The resistor needs to exchange heat with the metal body in order to be cooled down (thermal contact conductance).

 

[Winetree]

Just put Skylar's mic body in Ben's case. Tight fit.
Had to notch out the dense foam on one end for the mic connector end.
Now I can't close the box. Too much top and bottom foam.
The foam is too dense to compress.
Anybody dealt with this yet?

 

[0dbfs]

Max, The white market thread seems to have moved or gone away. Just wanted to post that I received my two kits yesterday. Thanks! Looking forward to it.

On another note from anyone that wants to respond, I was wondering about the tubes. ie; should I plan to buy more and select the best ones? What have y'all experienced with the supplied tubes?

More to follow as the build progresses!

Best,
jonathan

 

[bobine]

Just put Skylar's mic body in Ben's case. Tight fit.
Had to notch out the dense foam on one end for the mic connector end.
Now I can't close the box. Too much top and bottom foam.
The foam is too dense to compress.
Anybody dealt with this yet?

Same here.  I left the foam in the lid but removed the piece in the bottom (peeled it away from the side pieces). I can put a thin piece of soft foam on the bottom and it fits but doesn't give a lot of protection. Maybe later I'll replace both top and bottom with 1/4" dense foam.

 

[bobine]

Just finished the mic. First listen:  wow, this sounds really nice.

MK47 with Beezneez capsule in EQU47 body.

Huge thanks to all!

 

[0dbfs]

Yeah. I missed the boat on that one. Extra lashings with a wet dollar bill are well deserved!

-jb

 

[bruno2000]

My kits arrived today, thanks!
Same question as 0dbfs, what about replacement tubes?
Thanks!
Bruno2000

 

[crackerzot]

Just finished the mic. First listen:  wow, this sounds really nice.

MK47 with Beezneez capsule in EQU47 body.

Huge thanks to all!

Sure would love to hear a sample...  I'm getting ready to assemble my kit.  The MK47 and EQ47 arrived on the same day, but I've got to wait 3-4 weeks for my capsule from Thiersch.  Gonna try to get the P/S and cabling sorted while I wait....

 

[idylldon]

I'm not finding the 14K 1-watt resistors at Mouser.  Are 1-watt really necessary in this position? 

Thanks,
--
Don

 

[crackerzot]

Assembled my MK47 kit today, but this is the first mic I've ever assembled and could use some advice on where to source some brass angle stock in order to mount the board to Skylar's EQ47 rails.  Also, is there any special advice on how low to mount the board on the side rails?  Just low enough to be able to solder the heater legs to the board while having it make contact with the bottom plate?

Also, if I opt to use heat transferring glue to attach that heat resistor instead of drilling and tapping a hole for a bracket, where do I find such glue?  Sorry for all the noob questions... but I am one.  Cheers.  

 

[bobine]

I was impatient so I mounted the board with two zip ties. Works great...extra shock protection

I mounted it nearer the top and extended the heater resistor legs with some stiff bus wire so it contacts the bottom of the bell and stays put with spring action. Assembled it warms up nicely, but doesn't feel hot.


btw, I don't have deep experience with a lot of high end microphones, but this is certainly the best mic I have ever used. I used it tonight with a problematic whisky-voiced male singer who usually ends up with an SM7b because LDCs are not flattering.
I'd describe the recording as vivid and engaging; it was interesting to listen to; there was something about the presence of the sound that was fascinating.
There might be a little etching or ringing going on with some notes but overall it is a delight. It's a whole new level for me. I want another.
 

 

[crackerzot]

Thanks, Bobine, like you, I am in SoCal.  I have extensive experience (decades) behind the microphone (I do voice overs and I'm also a singer) but very little experience INSIDE of them. 

Zip ties.

Now why didn't I think of that?  Ha ha.

I guess I was thinking it was important for the PCB to be grounded to the rails?  Again, my lack of experience with the innards.

That ringing you mention might be microphonics from the tubes?  Very interesting.  I am definitely looking forward to having my mic completed.  Just waiting for the blue line capsule from Thiersch to arrive and I have a friend building the P/S for me so I don't electrocute myself or blow up my new microphone.  My build completion is at least another month out.  I think I'm going to try and put my hands on some 3M heat conductive tape to attach the heater, but your solution sounds better for mic tinkering later on.  If I adhere the heater to the bottom plate, it's going to be more of a PIA when I disassemble the mic.

 

[Winetree]

OK, got the PSB mounted in skylar's mic body, using nylon ties and the resistor mounted and wired.
How do i wire the 7 pin connecter to the PSB. I see A+ A- B+ B- and pins 1-7?
Same for the capsule wiring. I just want to do it right the first time.
Any help or pictures of finished insides?

 

[bobine]

I did mine like this, color coded the same at each end. I used Gotham mic cable.

Audio
1 = A- (gray) (connects to pin 3 of XLR at the power supply)
2 = A+ (white) (to pin 2 of XLR at the PS)
Center pin = audio ground (green)  (to pin 1 of XLR)

Power
3 = B- (black [blue in the cable])
4 empty
5 = B+ (red)

Pattern
6 = P (yellow)

Shield to the chassis.

I soldered the wires into the Binder connector, installed the connector in the mic body, mounted the PCB, then attached the wires to the PCB.

I forgot to take pics.  

 

[Winetree]

Great, Thanks.
Looks like a plan. I'll Use.
What about the capsule?