JK's MKU47 build thread

Tony said, "On a side note, i talked to winetree, we're going to do a big ole mic shootout sooner than later(it will include MKU47's and original serial#38 Neumann U47)


I say, ooh, ahh.. can't wait, and thanks in advance.

Looking great Tony. That's a fun and tedious build eh? I just sent kcats out today. Wanted to rebuild the PSU to make sure it was 100% safe. I have to say he got it pretty darn close with both the mic and psu. For a brand new diy guy he surely has the balls.

John's mic looks great. You're like me with attention to every detail. It does make a difference especially where reliability is concerned. I'll bet the list is long of folks ready to buy it if he doesn't like it. Not a chance though. I'll bet he names it "my precious".

Thanx Cat, yeah, a little attention to the small things prevents mistakes as it slows your roll, and keeps things running well longer i've found. Congrats on finishing kcats albatros lol, he's gonna flip on it! Curious, what was the fatal mistake on kcats rather brave 1st timers build? Maybe it'll serve as a heads up for others?

It's the teflon stand-offs.  I guess there is some sort of residue on them and even after a thorough cleaning with isopropyl alcohol solder isn't really too excited to stick very well.  A little flux paste is all it takes to get things moving along, but if you're using thin no-clean solder the flux in the core just isn't enough to clean the part.

He also overdid the loosening on the tube sockets so the tubes were flopping around loosely.  i replaced those, rewired everything and mounted/wired the capsule and the mic was essentially there.  The dropper resistor wasn't tightly fixed to the bell so wouldn't have gotten any heat transfer out of the mic but that didn't prevent things from working.

The PSU was a little messier.  I replaced the mis-matched 10W resistors with the values I told you about.  the board was pretty worked over from swapping parts out, but Zayance's boards are THAT good so it still works fine.  The stabd-off for the PCB were a little short so that the board was nearly making contact with the choke underneath.  That would have been BAD.  I raised it 1/4" and replaced/re-soldered all of the wires with new silver/tef.  I like to get a good solid ground connection with the enclosure too so I made a new ground point and removed enough powder-coat underneath to get good contact with the chassis.  The XLRs were pretty worked over too so I cleaned and re-did those, using heat shrink on the connections for extra strength.  The PSU is solid now, and I mistakenly wired up a blue LED to the front panel and decided to leave it since it looked so cool. 

kcat's mic is a gem now indeed.

You will have it Monday Matt!

So - does anyone have an extra M7 Capsule mount I can buy? Just trying to avoid waiting three weeks for shipping from Thiersch or Flea.

Saw all of those...the AMI one doesn't come with screws and they won't pick up their phone. The LeWison wasn't the right fit...but I think we've come to a solution.

here's the hi Z section built and installed, cat5 wasn't kidding when he said those teflon shielded capsule pins were tough! you have to clean them extremely, extremely well, and use flux paste/pen to get solder to bite, u want a minimum solder blob to keep capacitance off the fine capsule connections path, I had to do one pin 2wice. Clean everything really well!! I used blue loctite to keep things from vibrating loose. These tubes in all likelihood won't make the final cut? Now i have to install a "who cares" capsule for testing, build the Gotham cable, and finish up the PSU, inching our way closer 8)

Last time i built a mic i re-used the teflon pins from very cheap small chinese condenser mic. Often these come with 1 GOhm resistors as well, nice to keep when you slaughter one of them for electronic parts and hardware...

hey category5 do you tap both of the led's on dans psu off the zayance board? I taped the rear led from the iec connector to light when its plugged in at all, and the front comes on with the power toggle in the on position, i achieve the proper 105 B+ no problem so doesn't seem a problem, can you think of a reason this is a bad idea? i'm kinda second guessing my logic here.

to be clear, the logic is that the rear led stays lit to let you know the PSU is plugged in regardless to whether it's powered up or not.

thanx man
T

i'm at 5 weeks with Thiersch so consider yourself blessed.

So it was the surge protector?