MK-U47 - build thread

[gbruler]

@gbruler

I finally listened to those clips on my monitors. Your K7 shouldn't sound like that. My Arabella (K7 through an EF12 circuit) has no trouble with high end.  Check out Chunger's recording's of an MK47 with a Beesneez M7, which I would expect to be slightly darker than the K7:
https://app.box.com/s/dwdl8htubzwbp3wos0ym
https://app.box.com/s/50cp8xnfa601ih141xmj

Here's the whole shootout:
http://studio939.blogspot.ca/2014/11/vocal-microphone-and-capsule-testing.html

I'm planning on building an M7 and was trying to decide between the Thiersch Blue Line and a Beesneez M7 and decided on the Blue Line for a slightly warmer or darker sound than my current all Beesneez selection.

Even in deciding this, I have to remember that no shootout is perfect especially when comparing capsules in DIY mics where so much can be different beyond the capsules.

It's a lot cheaper to troubleshoot caps, wiring, etc than capsules. I think you should start there. You could also identify your location and see if there is anyone nearby who would allow you to try a capsule swap.

Thanks for that, at least someone noticed just how much our mic is muffled. I did hear Chunger's shootout, and it's actually one of the reasons I went for the beezneez capsule, it sounds darker than the others in a good way in this shootout. But my capsule is definitely darker and I'm not sure if it's in a good way.

Because all our numbers are correct, we have figured that it's not something with the circuitry of the mic, but we will check it again. Actually my dad does all the technical work, so I'm not sure about the gloves, but he has a lot of experience with this kind of things.

I have just mailed Veronica like some of you suggested and I really hope to get her reply soon.
Thanks again

 

[gbruler]

I want to purchase a thiersch blue line capsule, I tried to reach him via E-mail and through his website but I get no answer, is there another way to contact him\buy one of his capsules?

Thanks

 

[Phrazemaster]

I would keep trying. I've bought a couple capsules from them and it was no problem. Give them another email or two and wait a few days.

 

[DjaiTeam]

At Gbruler, or your can ask Banzai. He sells them too and you can trust him.

http://groupdiy.com/index.php?topic=54169.0

 

[Phrazemaster]

At Gbruler, or your can ask Banzai. He sells them too and you can trust him.

http://groupdiy.com/index.php?topic=54169.0

Yes but why not buy right from the vendor? Might take a little bit to connect with them but they are reputable and they are the actual dealer.

 

[DjaiTeam]

Thats true but sometimes time is the gamebreaker when you want to finish something...

 

[Zander]

Hi,

I'm having some issues with my build. I broke the reed switch & wrongly wired the cable. Luckily the reed was an easy fix and the cable had the audio- to ground so no harm done there.

Now when the first pair had burnt in, which had no noise issues. I wanted to change the tubes. I had to use a reasonable amount of force to get them out. So now one tube sits looser. I thought this wasn't going to be an issue but when I switch my power supply in the fuse keeps blowing... I immediately switched back to the tested pair and again another blown fuse. So I think the problem lies at the tube socket or the wires soldered to those. Now I want to check what's going on but I'm hesitating to power the mic without the tubes. How should I go hunting for the fault?

I'm also not quite convinced that everything sounds as it should. To me the mic sounds best in cardio but not what I expect from it. And in omni the front side sound high passed, the back sounds better... So where should I look for that?

Zander

 

[Pip]

Hi,


I'm having some issues with my build. I broke the reed switch & wrongly wired the cable. Luckily the reed was an easy fix and the cable had the audio- to ground so no harm done there.


Now when the first pair had burnt in, which had no noise issues. I wanted to change the tubes. I had to use a reasonable amount of force to get them out. So now one tube sits looser. I thought this wasn't going to be an issue but when I switch my power supply in the fuse keeps blowing... I immediately switched back to the tested pair and again another blown fuse. So I think the problem lies at the tube socket or the wires soldered to those. Now I want to check what's going on but I'm hesitating to power the mic without the tubes. How should I go hunting for the fault?


I'm also not quite convinced that everything sounds as it should. To me the mic sounds best in cardio but not what I expect from it. And in omni the front side sound high passed, the back sounds better... So where should I look for that?


Zander

Not a problem to power the mic without tubes and or capsule in circuit. Fuse blown means usually either dead short or loss of control of electron flow at tube so check and see that you didn't break one of the connections on the tube sockets. Make sure nothing it touching the body anywhere. Pics always helpful.

 

[Zander]

Thank you. I'll check without the tubes first. I need to go buy new fuses before. I remember that the led's intensity is too weak to mount on the frontpanel. Mine is very bright. I used another led than specified in the BOM. Mine is 3.2 Vf at 20mA and the one in the BOM is 1.7 Vf at 20 mA. Should I switch this? I find it interesting that it worked well before I switched the tubes.

Zander

 

[Zander]

Okay. With no tubes so no load the voltages seem good. 295 Vdc. I put the tested pair back in and it comes alive. I used 200 mA fuses. So I now must figure out why the 125 mA keeps blowing?

Heater 1: 17.5 Vdc (between pin 3 & 4)
Heater 2: 15.5 Vdc
Plate: 45 Vdc (red wire to ground)
Between 2M & 3M to ground: 56 Vdc
Backplate to ground: 5.7 Vdc

I found similar voltages in this thread so I guess they are OK? I'm still troubled with crappy sound of the front diaphragm.

Zander

 

[59flame]

anyone have the pics for wiring the teflon pins to the hi z part. I noticed they are gone on the build portion of this thread. i have the white wire, black soldered together, a yellow wire, and two green wires that probably get soldered together, but not sure. anyone care to help?

 

[Floti]

I also could´t find the pictures and ended up following the diagram on the top of the 1st page.

 

[Pip]

anyone have the pics for wiring the teflon pins to the hi z part. I noticed they are gone on the build portion of this thread. i have the white wire, black soldered together, a yellow wire, and two green wires that probably get soldered together, but not sure. anyone care to help?

If you are using Max's body they go in the three holes in the top metal plate. The one that the capsule mount and spacer disk  attach to. They are there so that the high impedance capsule wires can be passed through the top deck without any loss due to proximity to the ground plane top plate.  Green wire to front capsule Yellow to back capsule and third one to junction of 10NF cap and 100M resistor onhigh impedance board  and the capsule base. If my memory serves. Follow the Schematic it is actually quite good.

I don't know whats up with the pix thing as they load fine on my browser you might try another I use Firefox FWIW.

 

[59flame]

Where does the yellow wire  coming from the bottom resistor pcb tie at on the tube sockets. I'm assuming just to one side  of the yellow wires jumpered between  3rd pin of the tube sockets. Is this correct?

 

[59flame]

got it!

 

[59flame]

Anybody have a beesneez k7capsule and mount.  The mount has 2 screws on the bottom  where as I need 1 screw I am assuming. anyone dealt with this? Do I need a different mount?

 

[burglar]

I had the same problem with my BeesNeez M7 and Aputis body.  I bought some more perspex and made  new plates with the correct holes for the BN capsule.

 

[59flame]

well that might be a thought. I was hoping there was something i was overlooking but guess not. I wonder if a flea capsule mount is single mounting screw on the bottom and  would fit the breesneez capsule? Anybody know?

 

[Phrazemaster]

Why not just order a capsule mount directly from Beez?

 

[Category 5]

well that might be a thought. I was hoping there was something i was overlooking but guess not. I wonder if a flea capsule mount is single mounting screw on the bottom and  would fit the breesneez capsule? Anybody know?

Beesneez capsule fits any correct M7 mount.  The beesneez mount is useful for Chinese bodies that require a 2 screw (offset) mounting system.  Flea, thiersch, and Bouchard M7 mounts are historically correct and use a single, center screw mounting system.  They also feature a correct, electrically isolated, dampening post. 

Both types will fit any correctly sized M7 capsule.  Choose the one that fits the body you are using, or even better, get the historic one (if the height will fit) and drill a center hole to attach it. 

I have used ALL of the above mentioned mounts and they are all very high quality, and fit the M7 variants perfectly.