MK-U47 - build thread

[mateus]

Heya there io!
Amazing job in this one, as usual.

Do you have this big bad boy kit ready for shipping already?

Regards!

 

[Category 5]

3 batches came and went already.  I'm sure Max will be posting in the white market thread when he has some more.  Keep an eye out for it.  these mics are well worth it!

 

[ioaudio]

Yes, bad timing unfortunately, but i'm already working on the next batch!

-Max

 

[kcatthedog]

Yes, bad timing unfortunately, but i'm already working on the next batch!

-Max

Ho HO Ho !!!

luv Santa

 

[ioaudio]

I'm not sure if i will manage to finish the batch before early 2015, but I'll keep you updated.

 

[ioaudio]

Looks like i will have a very small batch soon available, check my WM thread for updates.

-Max

 

[stelin]

Just a picture of my MK U47. Looks nice, don't you think? If you want a high resolution version (print it out and hang it on your wall) just drop me an email.

- Stefan

 

[ioaudio]

Very nice pic - thanks Stefan!

 

[Melodeath00]

I think I may be in when the new batch is done. I simply have to compare to my EF802 U47

Two quick questions...

1) is the reed switch for "true cardioid switching"? I see no relay, but I'm unfamiliar with how reed switches work - that's why I'm wondering. I am having trouble visualizing where the reed switch connects to the body switch.

2) Is anyone selling a 105V U47 PSU PCB and case?

 

[djn111]

Hello,

Very nice pic .

Working on one myself did al little bid design work:

This logo for on the mic, inspired by the first serie of U 47, hopefully made out of polished stainless steel.

And this one to put on the powersupply, and at a serial number.

DJN

 

[djn111]

Hi,

A reed switch is triggered by a magnetic field. If a magnet is near, the switch closes in this case. The reed switch is sealed in a glass tube, so no corrosion is possible, so a good choice for this application. The magnet is concealed in the cardiod omni switch.

Your next question, build A PSU point to point, not a lot of parts inside.

I have a fairly complete mouser part list if you like to start from that.

Hope this helps.

Kind regards DJN

 

[Category 5]

I think I may be in when the new batch is done. I simply have to compare to my EF802 U47

Two quick questions...

1) is the reed switch for "true cardioid switching"? I see no relay, but I'm unfamiliar with how reed switches work - that's why I'm wondering. I am having trouble visualizing where the reed switch connects to the body switch.

2) Is anyone selling a 105V U47 PSU PCB and case?

Zayance just did a new run of PSU PC Boards and they are beautiful!  Get one quick.

 

[kcatthedog]

if you buy a zayance pcb he gives you a bom for mouser

people are buying cases from dan at collectivecase

 

[ioaudio]

Yes Zayance's boards - recommended.

 

[Bri_guy]

Hi guys,
I'm having some issues with low gain and contant hiss. My build is outfitted with an EF 14 tube...has anybody else used an EF tube that can help me troubleshoot?
Thanks,
Brian

 

[kcatthedog]

how long were they burned in ?

 

[Bri_guy]

I didn't really burn them in for any extended time. Do you think that a burn in period would affect these issues?

 

[kcatthedog]

48 hours  minimum is standard I think ? 

also the sand resisters have caused  some noise and some have replaced with the aluminium clad ?

others may chime in ?

 

[ioaudio]

His build is with a EF14, and the MK-U47 was always delivered with the sand resistor (which is not used for a EF14 build)

Brian, which circuit are you using? I see you have several EF14 tubes to try - maybe record a sample of the noise?

-Max

 

[Bri_guy]

We started with the dual glass tube design, and the noise and lack of gain led me to try an EF design (also the mic body heated up quite a bit).  I'm wondering if I got something wrong from the start (before I decided to switch to the EF). In any event, Myself and  my studio tech reworked the PSU to work with the dual power requirements of the EF design, and referenced Oliver's schematic as well. The mic sounds good tonally, but when I put it up next to one of my other U47s (I have an old VF long body and a Wunder CM7 with an EF)...it's about 20db quiter....so the noise that I'm referring to is actually due to the signal to noise ratio (at least I think). I'd love to compare my build with someone who has modified their MK-U47. Do I need to change the transformer configuration (BV08)? If I have time tomorrow, I can record a comparison between the MK and my old 47.