GroupDIY

Project Specific Discussions => Microphones => Topic started by: ioaudio on December 08, 2012, 10:42:26 AM

Title: MK-U47 - build thread
Post by: ioaudio on December 08, 2012, 10:42:26 AM
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/MK-U47.jpg)
MK-U47 Tube Microphone Kit featuring:

Costum Headbasket made by Flea with Pattern Switch
Brass made body tube and bottom bell, bead-blasted and nickel-plated
Stainless internal structure
Bv.08 Transformer with 8 seperate sections from my own production
6028 single supply circuit with all parts including

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/MK-U47-Kit.jpg)

including (back left to right):

body tube
bottom bell with power resistor mounted + internal structure
Headbasket pattern switch
Transformer + resistor board
High-Z board with screws, teflon isolators, shims for variable capsule mount height
solder lugs and subminiature reed-contact
Black rubber band for tube shock-mount
Tube deck + tube sockets, screws,


(front left to right):
Wiring, yellow wire sleeve, shrink tube
Binder connector for mic and cable
Bv.08 Transformer
PIO and styroflex capacitors, resistors

to complete the microphone, you'll need:
a capsule + holder
a single supply 105v PSU
a microphone cable (cable connector to mic included)

Completed kit with Flea capsule holder:
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0125.JPG)


-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
BUILD:

Schematic:

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/MK-U47_Schematic.GIF)

Wiring Plan:
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/Mk-U47%20Wiring.jpg)

we start from the bottom up.

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_174523.jpg)

Use small pieces of wire to bridge contacts as shown

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_200816.jpg)

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_200853.jpg)

wire the connector according to the original schematics
Solder a lug to the end of one black wire
1: White
2: Blue
3+4+6: Black x 2
5: Red

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_204403.jpg)

Unscrew this resistor

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_201707.jpg)

Solder yellow and red wire

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_201935.jpg)

use shrink tube for isolation

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_202039.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_202120.jpg)

mount the resistor back in

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_202253.jpg)

unscrew the ring of the connector and place it
in the bottom bell, aligning the keyway/slot

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_205327.jpg)

carefully place the ring and tighten

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_205618.jpg)

unscrew the nut and place the solder luck and re-tighten

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_205701.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_205747.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_205852.jpg)

paint the transformer/resistor board (not shown: use a file after breaking)

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_210029.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_210450.jpg)

Solder together the boards as shown, check for right angle

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_210601.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_210645.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_211701.jpg)

place and solder all resistors as shown

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_211810.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_213220.jpg)

place and solder all wires as shown

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_214842.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_215555.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_215607.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_215727.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_225335.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_230005.jpg)

Be careful handling the transformer
place and solder the transformer as shown

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_230135.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_230235.jpg)


Before soldering the big capacitors it's time to mount the whole thing into the mic

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_230758.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_230922.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_231252.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_231353.jpg)


insert the screws and attach the nuts, do not overtighten!

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/normal_20140619_231526.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/normal_20140619_231638.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/normal_20140619_231942.jpg)

Place and solder the two green capacitors as shown

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/normal_20140619_232206.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/normal_20140619_232328.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/normal_20140619_232409.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_232504.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_232901.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_233231.jpg)

The yellow sleeve will be cut like this to fir through the hole

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_234456.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_234535.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140619_234601.jpg)

Carefully cut and drill (pierce) the rubber band as according to this measurements

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/Rubber_Band.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_004633.jpg)

unscrew these parts

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_004758.jpg)

mount the tube sockets, check for orientation!

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_004911.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_012445.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_012525.jpg)

bend and add a solder lug

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_014549.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_014645.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_014724.jpg)

attach and solder short black wire

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_021444.jpg)

Wire up as shown

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/Tube_wiring.jpg)

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_022338.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_022358.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_022603.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_023256.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_024343.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_024458.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_024520.jpg)



attach the rubber band

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_024752.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_025257.jpg)

mounting the tube deck

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_025410.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_025459.jpg)

feed through the wire sleeve

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_030422.jpg)

attach the yellow, red and blue wire to the corresponding pins

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_031232.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_031514.jpg)

Be careful with overheating when building the highZ portion of the circuit

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_031928.jpg)

bend and place the solder lugs as shown

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/20140620_234527.jpg)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0072.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0073.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0074.JPG)


a small wire bridge, do not solder yet

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0076.JPG)

the reed contact must be oriented and placed carefully BE VERY CAREFUL HERE

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0077.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0078.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0079.JPG)

do not bend the contact after soldering or i will break



you can hold the tiny contact like this for placement

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0080.JPG)

to have free access, slide the middle lug away

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0081.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0082.JPG)

the contacts inside the glass envelope must be oriented this way

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0083.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0084.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0085.JPG)

solder second side only after orientation is correct

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0086.JPG)

more wire bridges and placing parts, place everything before soldering, solder quickly

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0087.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0088.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0089.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0090.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0092.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0093.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0094.JPG)

the teflon feed throughs

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0095.JPG)

push the carefully to place, grabbing them by the top teflon part

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0096.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0097.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0098.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0099.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0100.JPG)

solder the two black wires

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0101.JPG)

mount the highZ board + spacer as shown

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0103.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0104.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0105.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0106.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0107.JPG)
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0108.JPG)

attach the wires to the teflon feed throughs

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0111~0.JPG)

attach the rest of the wires

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/hiZ-wiring.jpg)

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0113~0.JPG)

place the tubes

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0117.JPG)

Shown with a Flea capsule holder

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/PICT0125.JPG)




Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: pasarski on December 08, 2012, 12:13:23 PM
Wow. Yes.  :)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: bernbrue on December 08, 2012, 01:12:00 PM
Excellent work, Max!
regards
Bernd
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: lolo-m on December 08, 2012, 01:39:56 PM
Great work ! This is definitely the year of the mic !

Interrested in 1 (without labeling on it) depending on price... Do you have a price ballpark ?
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: zayance on December 08, 2012, 01:59:05 PM
 :) 8)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: moltenwok on December 08, 2012, 02:06:52 PM
Amazing work mate-just starting the same process with C12. Ive got a matched pair of Tim's capsules and just can't put them in a Chinese body of the wrong dimensions and materials! Certainly like to purchase 1 of these when available!
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: micaddict on December 08, 2012, 03:29:17 PM
 ;D
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: Gus on December 08, 2012, 04:25:41 PM
Are you using cutting fluid?  I see tool marks in the bases.

IMO it is good to get the best finish you can when turning metal on a lathe or milling it before finishing it.
Correct speed, tool shape,cutting rate and cutting fluid brushed on or mist or flood.  I like mist setups mix of air to remove chips and cutting fluid when you want to see what is happening.


Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 08, 2012, 07:25:31 PM
thanks for your kind comments.
The labeling on the mic is only temporary for my cad drawing.
I'll try to keep the price as DIY-friendly as possibly, but keep in mind that the used copper-alloys do cost like 4 to 6 times more than materials used in other mic housings.

Gus, shown is a pic from after the roughening job done - those are not finished yet.
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: Matador on December 08, 2012, 08:26:32 PM
I like the tool marks!  One could make a kick-ass steampunk microphone!
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: okgb on December 08, 2012, 08:57:55 PM

 Guesstimate on price ?
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 09, 2012, 05:39:57 AM
Not just yet, Greg - still need to evaluate pricing on the finish (galvanisation)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 09, 2012, 11:11:13 AM
I like the tool marks!  One could make a kick-ass steampunk microphone!

i also like em, working with brass is just nice.
I got two pm's asking why i would make my housings from brass - the vintage U47 in the lower serials was made from brass (incl the body tube)  like this:
http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Neumann-Mikro/U47/U47.htm

Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: zebra50 on December 09, 2012, 12:15:21 PM
Brass seems very sensible to me - much easier to work with on a small run. Although your production run looks quite big!

Anyway, looks good so far - I'm watching with interest.
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: micaddict on December 09, 2012, 12:45:36 PM
Quote
I got two pm's asking why i would make my housings from brass - the vintage U47 in the lower serials was made from brass (incl the body tube)

Yup.
Many seem to think aluminum is the true original material.
Most numbers, yes.
First, no.

About the brass. Strictly speaking, that would be copper/zinc. But "gunmetal" also contains tin (copper/tin=bronze, although in a looser sense just about any copper alloy is called bronze) and sometimes even lead. It's called red brass here:
http://en.wikipedia.org/wiki/Gunmetal (http://en.wikipedia.org/wiki/Gunmetal)
Max, could you tell us the metals and percentages in your alloy?
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 09, 2012, 01:39:08 PM
i use both - brass (MS58 and MS63) and gunmetal (Rg7)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: micaddict on December 09, 2012, 03:50:42 PM
OK, thanks.  :)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 10, 2012, 06:32:39 AM
Working on the lower rings for the headbasket - this material is RG7 - it's a bit darker than brass

(http://www.twin-x.com/groupdiy/albums/userpics/rg7.jpg)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: Tsane on December 10, 2012, 07:57:41 AM
Looking great! Definitely interested in one when these become available.
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: Rossi on December 10, 2012, 08:11:56 AM
Nice!  ;D
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 10, 2012, 09:20:16 AM
Headbasket lower rings turned, waiting to be drilled

(http://www.twin-x.com/groupdiy/albums/userpics/normal_lower_rings_headbasket.jpg)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: zayance on December 10, 2012, 09:21:32 AM
hmmm, my bank account won't like it.................but might be interested.


Looking good...

Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: kilmister on December 10, 2012, 12:07:15 PM
Mmmm, mine neither..
Max, can you give any estimated price range yet?

-Paavo
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 10, 2012, 02:05:29 PM
I'd rather not give numbers bevore i have them together (total hours worked, money spend on the finishing/galvanising, tools etc)
It will be more than alternatives made in China, but i think they'll be wort it.

-max
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: chunger on December 10, 2012, 02:57:50 PM
This is very cool.  Are you planning original 3 rail type internal frame or a 2 rail frame setup?
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 10, 2012, 03:58:03 PM
Thanks 'chung! Original 3-rail 120° arranged.
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: BraFra on December 10, 2012, 05:49:50 PM
If the rails will be interchangeable with original and looks like this exact model, I'll be interested in 6 of them.

Fra
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 11, 2012, 07:45:32 AM
They'll be similar, but without the notch.
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 11, 2012, 01:58:20 PM
top rings:
(http://www.twin-x.com/groupdiy/albums/userpics/upper_rings_headbasket.jpg)

Initially i planned to document the process in detail, but work is intense so i just took a few snapshots...
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: riggler on December 11, 2012, 02:08:20 PM
Hello Max,

Do you have your own lathe there? Looks very good! I have read up on facing, finishing, plunge and side cutting. I would love to have my own lathe. I am curious to see how you will drill the holes for the screws that mate the pieces. (for the m49s you need to have three holes precisely at 120 degrees) Anyway, this is rad!
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: zayance on December 11, 2012, 03:48:21 PM
Hello Max,

Do you have your own lathe there? Looks very good! I have read up on facing, finishing, plunge and side cutting. I would love to have my own lathe. I am curious to see how you will drill the holes for the screws that mate the pieces. (for the m49s you need to have three holes precisely at 120 degrees) Anyway, this is rad!

You'd use a Rotary indexing tool, if not using a CNC.
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 13, 2012, 12:10:20 PM
I'm going manually at the moment (except mill work like the M7 capsule) lathe bandsaw indexing table etc but i'm looking into a cnc-ed lathe as well.
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: David R. on December 13, 2012, 02:01:27 PM
As my 1 1/2 year old daughter would say, "mine?"
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: jackymurda on December 16, 2012, 12:34:40 PM
looks wicked.. :)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: drumminkiger on December 18, 2012, 06:00:30 AM
Group DIY needs a "Like" button for stuff like this :)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on December 20, 2012, 10:30:58 AM
thanks guys.
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: mateus on December 24, 2012, 06:16:10 PM
Amazing!! This time I won't miss the chance! =)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: Phrazemaster on December 29, 2012, 04:04:17 AM
Looks wonderful! I'll be very very interested when you complete this and have it ready!
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: Phrazemaster on January 10, 2013, 03:56:49 AM
Any more word on this max? :)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: monkeyxx on January 11, 2013, 04:59:26 PM
I'll be interested too, depending on price!  :)
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on January 11, 2013, 06:11:18 PM
not yet. demand on mk47 pcb kits is bigger than anticipated, so i'll prepare more before i return to the housing.
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: andia on January 16, 2013, 07:43:14 AM
Hi!
will the housing also contain the inner construction to mount the electronics and will this be like in the original?

thanks,
andi
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on January 16, 2013, 11:41:29 AM
I'm still thinking about what to include, maybe i'll offer two packages - but the inner structure with the rails will be included for sure.
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: Majestic12 on January 16, 2013, 11:58:07 AM
Hm...I'm not sure what to do. The Equinox body will be available in a few days and surely be sold out quick... but yours seem to be the same high quality and also lower shipping costs to Germany....
Title: Re: MK-U47 all brass/gunmetal mic housing - coming soon
Post by: ioaudio on January 16, 2013, 04:38:26 PM
This body is made from brass and gunmetal and made in austria, i don't want (nor can't) compete with aluminium bodies made in china.
Title: Re: MK-U47 all brass/gunmetal mic housing
Post by: Phrazemaster on March 12, 2013, 01:30:53 AM
Anything ever happen with this project? Sounded so nice!
Title: Re: MK-U47 all brass/gunmetal mic housing
Post by: jackymurda on March 12, 2013, 08:29:50 AM
yeah they look heavy duty... did they ever get finished? :D
Title: Re: MK-U47 all brass/gunmetal mic housing
Post by: ioaudio on March 12, 2013, 12:37:04 PM
I'm working on it.
Title: Re: MK-U47 all brass/gunmetal mic housing
Post by: Phrazemaster on March 12, 2013, 01:43:57 PM
 ;D
Title: Re: MK-U47 all brass/gunmetal mic housing
Post by: ioaudio on March 17, 2013, 03:56:32 PM
I'm getting there slowly...Plan to include the pattern switch via magnet/reed contact...this project is evolving to a kit with point to point electronic parts, connectors etc
Finished the inner structure, turning parts, headbasket toolings etc.

(http://www.twin-x.com/groupdiy/albums/userpics/progress.jpg)
Title: Re: MK-U47
Post by: Dr Gris on March 18, 2013, 01:38:05 PM
Hi Max,

It was a long time ago since we met in Vienna and I bought a pair of mics from you.
They are still the best I have for certain things.
I' m really amazed by your work, especially these latest creations, this is just crazy....
Looks like you have a steel tube in mind, or that ring is just for true to the original cosmetics??
How are those M7' s coming along? Man, that' s also crazy  ;)

Last year I invested in some nice mics so I' m kind of broke at the moment but please don' t forget
about me when this hits the market. I can only imagine how fast these will go...

Here' s a photo of your babies in good company, please excuse the tejp...

Best regards
Magnus
Title: Re: MK-U47
Post by: canidoit on March 18, 2013, 05:45:44 PM
How much do you think the full kit will cost?

Will you also be selling the power supply to run it??

Thanks
Title: Re: MK-U47
Post by: ioaudio on March 21, 2013, 08:39:58 AM
Hi Magnus,

long time - great to see the mics got such nice company!
Thanks for your kind words. The black ring is made from rubber and it's used as a shockmount for the tube, in my case it's two miniatures.


canidoit,
i still have to negotiate a costs for the galvanisation and a few other things before i can settle on a pricing.
The psu will most likely not be included.

-max
Title: Re: MK-U47 Kit Brass Housing & New Bv.08 transformer
Post by: ioaudio on March 26, 2013, 02:24:34 PM
Also part of the upcoming kit:
Full-stack, 8-chamber wound Bv.08 transformer with two mounting holes - fully compatible to the original:
(http://www.twin-x.com/groupdiy/albums/userpics/Bv_08_prototype.jpg)
Title: Re: MK-U47 Kit Brass Housing & New Bv.08 transformer
Post by: micaddict on March 26, 2013, 03:00:51 PM
 :o


Now what to do with my old MK47 ..............
Title: Re: MK-U47 Kit Brass Housing & New Bv.08 transformer
Post by: 0dbfs on March 26, 2013, 03:26:33 PM
:o


Now what to do with my old MK47 ..............

Get her a sister and stick her in front of a kit/amp/ac-gtr?

Ciao,
jb
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: Winetree on March 26, 2013, 04:20:54 PM
"what to do with the old MK47"
Why, Is there going to be a "sound" difference with the new transformer, kit?
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: micaddict on March 26, 2013, 05:04:37 PM
I guess I should have added this guy:  ;)
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: ioaudio on March 26, 2013, 05:08:15 PM
Transformer&tubes installed.

(http://www.twin-x.com/groupdiy/albums/userpics/trans_tubes.jpg)
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: dmp on March 26, 2013, 05:23:17 PM
This looks amazing Max. Great job.
Maybe you shouldn't include everything in the kit, so we can feel like we did some work too   ;)
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: Phrazemaster on March 26, 2013, 06:36:16 PM
Just stunning...I'm afraid it might be a little too high end to even call DIY but...I'm drooling! Way to go sir!
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: ioaudio on March 26, 2013, 08:48:00 PM
That's how the non-contact pattern switch works:
The small magnet slides in the active zone of a miniature vacuum reed contact and actuates omni pattern.
(http://www.twin-x.com/groupdiy/albums/userpics/normal_pattern_reed.jpg)
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: zayance on March 27, 2013, 06:14:22 AM
Nice stuff.

Actually didn't spotted that but You went for Amphenol Connector? Nothing wrong with them, just asking.
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: micaddict on March 27, 2013, 06:52:32 AM
Hey, a third glass tube!  ;D
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: ioaudio on March 27, 2013, 09:32:31 AM
It's a smaller Binder connector.
And yes - the glass tubes are my leitmotif  ;)
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: micaddict on March 28, 2013, 06:53:38 AM
Seems like a good leitmotif, too. Keep at it.

OK, in all seriousness now, will the bigger tranny sound different from your earlier one? E.g. will it provide deeper bass?
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: ioaudio on March 29, 2013, 04:55:35 PM
In conjunction with a 0,47µF capacitor (instead of 1µF) the transition steepness changes.
Also, the added chambers divide the stray capacity, it's basically 8 sperate coils working on one core.
To my knowledge this will be the first commercially available Bv.08 copy with physically seperated windings.
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: wave on March 29, 2013, 07:47:27 PM
Once again your work is beautiful Max! Another mic project to save up for!

Dave
Title: Re: MK-U47 Kit: Brass Housing & New Bv.08 Transformer
Post by: EvLoutonian on April 03, 2013, 09:50:41 AM
Once again your work is beautiful Max!

Wow. Beautiful work.
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: North on April 03, 2013, 10:46:01 PM
Max this is looking great! Cant wait to see the finished product.
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: jackymurda on April 04, 2013, 09:05:10 AM
dude is on some crazy mad scientist ting!! :D
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: BraFra on April 05, 2013, 07:32:51 PM
Hi max,
I've read that you are doing lamition by yourself for this transformer, could describe the alloy mixture used? The same as A51 garantie that u described in the bv-08 post? May i ask if is possible to buy those lamination from you? Thanks and sorry for the little ot.

Fra
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: Dr_J on April 06, 2013, 06:30:49 AM
What a great project!!! Wow!!

A dream of mine is to do something similar one day, if i'll ever have the time  ;D

ROCK-ON!
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: micaddict on April 06, 2013, 08:06:56 AM
These quotes no doubt originate from the REPforum, but I copied them from a Gearslutz thread:

"The only feature where the last version of the u47, which was named the u47a, differs from the earlier u47 shortbodies is the output transformer, BV8b, whereby the secondary is wound over the primary. The new transformer can be identified by the label 'BV GN 8b', which is clearly visible under the transformer's amber wrapping paper, on the top facing surface of the double bobbins. It produces ca. 4 dB less output into 1k Ohm mic pre inputs.
Martin Schneider at one point also posted that there was another transformer available on the u47a model, a BV8a with 600 ohms output imnpedance. I have never seen that model. All other components seem to be aboslutely identical between both models, to my knowledge.
Kind regards, Klaus Heyne
=============================================================
X-formers used in the U47 have several different version (.......), but aside the early Hiller made ones, the BV8 used since approx. serial# 200 are nearly same in sound, there are two different winding technique versions and than the 12.5/50 Ohm, 200/600Ohm and the most used and popular the 50/200 Ohm version.
X-former difference is easy to figure out the early U47 were frequency limited to 40 Herz by separating specific winding parts to get the IRT required low cut. Later U47 just used a .5uF coupling cap instead the earlier 1uF. The sound of the x-former is very similar. U48 had the later x-former with .5uFcoupling cap.
The sound of the U47 outputs differs from mic pre to mic pre, you want for the 200 Ohm strapping a min. of 1k or the perfect mic pre is the Telefunken V41 with 2K input, the historical mic pre of the IRT 40 series made by Telefunken, Maihak, Siemens and EAB.
The historic 1950s power sup. is probably the best you can find for your mic, you might want to change the filter caps and the old cloth wire, but anything else they work very reliable. The 450V is just open without any load, but to be sure not to kill your mic due to dried out filter caps, etc, you might want to use a variac x-former to bring the voltage up very slowly to make sure that at given line voltage you have 105 Volts.
Best regards,
Oliver"
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: micaddict on April 06, 2013, 08:28:51 AM
Max wrote in reply #66:

Quote
In conjunction with a 0,47µF capacitor (instead of 1µF) the transition steepness changes.

In the quote, Oliver mentions the cap change, too FWIW.  :)


Quote
Also, the added chambers divide the stray capacity, it's basically 8 sperate coils working on one core.
To my knowledge this will be the first commercially available Bv.08 copy with physically seperated windings.

First such copy, but did it actually exist in the old days or is this a new twist you came up with?
Excuse my ignorance.
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: ioaudio on April 06, 2013, 10:16:13 AM
Thanks for the kind words evryone!


micaddict,

no new twist, all original Bv.08 transformers have been made on the chambered bobbins.
(http://www.twin-x.com/groupdiy/albums/userpics/PICT0170.JPG)

-max
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: micaddict on April 06, 2013, 11:11:50 AM
Thanks, Max!

I don't know enough about the chemistry to join in the discussion between you and Moby.
What I do know is that some say the older metals were more pure and others say the older metals were less pure.
And some say there were toxic ingredients that can no longer be used.

 :-\

Henk
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: micaddict on April 06, 2013, 11:41:51 AM
Do I recall well that your original laminations were used up in the earlier batches of the MK7 (not MK47) kit?
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: ioaudio on April 06, 2013, 11:42:47 AM
yes.
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: ioaudio on April 08, 2013, 08:17:24 AM
One more quick rendering from my drawing, also showing the innards:
(http://www.twin-x.com/groupdiy/albums/userpics/Render3.jpg)
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: ioaudio on April 08, 2013, 08:41:54 AM
I also updated the first post with more pics.
Title: Re: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: BraFra on April 08, 2013, 06:01:36 PM
Moby,

actually the transformer i sent you in 2008 was made from original laminations Garantie a-52 made by VAC in the 70-ies.
So what you analysed was a product made by Vacuumschmelze Hanau, not my own.
Of course, I analyzed Garantie A-52 (Sourced from Belgium gentleman) winded by you,  and few more original Neumann's (not yours) lams including the early (less nickel) and later (more nickel) BV8's. Of course there is the very first "very low nickel" laminate used in the first U47 but that's another story because it's not UI30 ;) But if you are curious, there is just a slight difference between those and 50's "low nickel" . I don't use "garantie 50,51,52" def's because it's connected just to one manufacturer of the UI30 lamination. Besides VAC U know that Krupp also made these but there is one more manufacturer in that game, actually complete manufacturing went to USSR after the 2. WW. Unfortunately they never stamped UI30's but it's still possible to buy sheets in that thickness and with same chemistry but in large quantities. They also look like VAC's (they are not black anodized) U know that yellowish shine :))) MAX, again, I don't want make any confusion or to share some suspicious minds . I just share my knowledge to the people here in the community. Don't take it personally.
Also, as far I know A52 was never used by Neumann. On the other hand I don't have any problem with it because is soooo, similar to later "H nickel" chemistry. To be precise it contains 2% less Nickel exchanged for Molybdenum because they "improved" that way earlier A51.

Very interested in this discussion, may I ask the exact chemistry of A50, A51 and A52? And how this chemical difference impact on the magnetical and electrical result of the core?

Fra
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: micaddict on April 09, 2013, 03:51:25 AM
Quote
Just take a listen the sound examples at Cinemag site where you can compare old with new alloy directly.

Yep. I was some time ago I listened to those samples, but I do remember the very obvious difference. I also remember being amazed that apparently some seemed to think they sounded very similar indeed. Well, some may have been biased, of course.
Not to put down Cinemag BTW. They make great trannies.


Quote
Sorry I can't post the complete chemistry since it's never been published and I really don't know the consequences of making it public.

Right now, I can't think of anyone who would not benefit, except maybe yourself. (?)


Quote
I made all the analyses to learn something or maybe to make old soft magnetics alloy available to the DIY community.

So exactly in what way will it become available to the DIY community then?
Seriously interested.


Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: ioaudio on April 09, 2013, 07:17:52 AM
edit
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: micaddict on April 09, 2013, 07:41:17 AM
 :o Wow, this looks like modern art.

And the upper right and middle left could be abalone shells.

And the yellow MOP completes the magenta and cyan, for those who are into photography.

And what about the shades of grey, for those ......... um, never mind.

Useless post. Sorry. Just had to share.  :P

Anyway, do keep this stuff coming!
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: BraFra on April 09, 2013, 02:25:33 PM
So from what I can understand searching the net, all the three A50, A51 and A52 should have Ni 50% content and Mo content from 3.5% to 4% and Fe to balance. This will tell that the only difference in the alloy mixture is in the Mo and Fe content, but from what Max is saying the Mo content give different response in the heat annealing treatment, and from what I can understand searching the net Vacuumschmelze and Krupp had different approach in this treatment, so how is possible that Neumann used all the two supplier over the time without having to change their transformer?

Fra
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: BraFra on April 09, 2013, 06:10:21 PM
So from what I can understand searching the net, all the three A50, A51 and A52 should have Ni 50% content and Mo content from 3.5% to 4% and Fe to balance. This will tell that the only difference in the alloy mixture is in the Mo and Fe content, but from what Max is saying the Mo content give different response in the heat annealing treatment, and from what I can understand searching the net Vacuumschmelze and Krupp had different approach in this treatment, so how is possible that Neumann used all the two supplier over the time without having to change their transformer?

Fra
Nope. Not even close to true chemistry. Don't try to google about it it will just mislead you . There is a lot false infos on the net regarding this types of  alloys. BTW,  alloys used in the first era of U47 up to 1953. is very different to later (one I tested was from 1958) Let's say that later is more complex , and of course with better permeability.

For having the information about the 50% nickel content I have contacted two of the main manufacturer that proclaims to build correct replicas, so there are two possibility or their replicas are not so correct or they want to keep their secret ;)
Anyhow could you tell me where I can get correct information without having false infos?

Fra
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: micaddict on April 10, 2013, 04:54:41 AM
I'm afraid that chemical composition is trade secret together with annealing process. It's up to you to listen, compare and finally decide.

I'm still in a mist here. Nothing wrong with secrets, but exactly who "owns" this 60-odd year old knowledge?

Quote
possible consequences with present  Bv.8 replica manufacturers. There is one of them doing it  close enough to original and I think he will be really pissed of if I just put that info in the ear .

This person X doing it close enough to original according to you, suggests you know at least as much as he does (more in fact). So why wouldn't you be free to share this? Surely anyone who's capable can do his own analyzing and research. But does this mean that the first one who puts something resembling the old product in the market automatically gets protection and others can no longer talk about the details? Or is there such a thing as patent re-incarnation? Or is it just a gentlemen's agreement about this among "lamination guys"?

Not trying to push you into revealing things you don't want to (and I appreciate the info we did get!). Just trying to make sense out of it. And I basically write this because it seems you're in some sort of a dilemma. You did come over to Max's thread and on the one hand you do want to share or at least help making the old materials available again.

BTW do you sell materials, or do you plan to? 
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: ioaudio on April 10, 2013, 05:28:20 AM
Edit
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: BraFra on April 10, 2013, 10:24:11 AM
I'm afraid that chemical composition is trade secret together with annealing process. It's up to you to listen, compare and finally decide.

I'm still in a mist here. Nothing wrong with secrets, but exactly who "owns" this 60-odd year old knowledge?

Quote
possible consequences with present  Bv.8 replica manufacturers. There is one of them doing it  close enough to original and I think he will be really pissed of if I just put that info in the ear .

This person X doing it close enough to original according to you, suggests you know at least as much as he does (more in fact). So why wouldn't you be free to share this? Surely anyone who's capable can do his own analyzing and research. But does this mean that the first one who puts something resembling the old product in the market automatically gets protection and others can no longer talk about the details? Or is there such a thing as patent re-incarnation? Or is it just a gentlemen's agreement about this among "lamination guys"?

Not trying to push you into revealing things you don't want to (and I appreciate the info we did get!). Just trying to make sense out of it. And I basically write this because it seems you're in some sort of a dilemma. You did come over to Max's thread and on the one hand you do want to share or at least help making the old materials available again.

BTW do you sell materials, or do you plan to?
Good questions  :) As far I know "secret" is owned by Neumann, Vac, Krupp initially, but few more small companies know about it too. I' not sure is it copyrighted but in case it is I will be quet  :D The problem with making thiss material is not  just because of knowledge. Main problem is that more modern materials are used in nowdays soft magnetic applications such as shielding etc... It's not a big deal for companies as VAC to make it again but they don't see any profit in pro audio since It's small market. On the other hand  pro audio market is overloaded with different (bad,better or good enaugh) replicas of vintage transformers and I'm not sure is it there a space for new replica products.
The other reason I don't want to share info is because I don't want to ruine somebody buisness or to popularize any company or name. Also, It will be hijacking Max thread and hard work. I just answered on alloy chemical composition question .
Do I have a plan to produce it?  Well, it's possible but we will need a serious number of guys to be interested. We can start a new thread and  put the feeler about it. Also, if Max's lamination is made with exact chemistry there is no need to do that. We still have not that answer, just that it's  proper dimensioned and that coils are wounded based on Neumann's blueprint. I can only judge from the picture (same as you) and it looks a bit "blacky"  (black oxide) what can be the product of different annealing process. Did I miss some answer? Probably yes, but this Ipad's screen is so small for me ;)

It's not copyrighted, because if it was copyrighted it will had to have a patent and everybody should be able to find searching over patents, since there is no patent about there isn't also a copyright. Ruining somebody business I don't think since like I've said two of the main builder of transformers replica were wrong about exact percentage of nickel content, so the only effect in the "revelation of this secret" will be that everybody can ask to the builder the chemistry formulation of alloy and only the correct one will gain the right to claim about "historically correct" replicas, I think that in the microphone section of a forum about diy this should be the right thing to do. Anyhow if you want to keep this secret for selling it to someone you can do it, but I think that you should tell it clearly ;)

Fra
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: Biasrocks on April 10, 2013, 10:58:07 AM
Food for thought.

Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: bobine on April 10, 2013, 11:25:56 AM
Someone suggested a new thread for the discussion of lamination materials...  excellent idea.
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: Gus on April 10, 2013, 06:52:40 PM
This kind of thread is one of the reasons I don't post that much anymore.

ioaudio and Moby did work to figure out the lams and treatments.  Did anyone else that asked for information do any work themselves?  Would they even know what to test for? 
I would not give up the information for free.

Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: micaddict on April 11, 2013, 06:20:08 AM
Since the shoe doesn't fit, I won't wear it.

And one of the the reasons I love to post here I the positive spirit displayed by most.  :)

Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: HellfireStudios on April 11, 2013, 01:04:37 PM
If Moby's claims are true, the easy way to resolve the issue is to have Max send Moby some lams to see if the chemistry corresponds with Moby's findings. If it is the same, Max will have a major selling point. If not, then maybe Moby (sorry for the alliteration) could share his knowledge, and a correct re-creation lamination could be produced. Either way it would benefit the DIY community.

-James-
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: ioaudio on April 11, 2013, 05:48:02 PM
edit
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: Pip on April 11, 2013, 07:18:13 PM
I was wondering also if maybe the discussion about the transformer core material should have it's own thread. It is facinating stuff and obviously a very passionate subject. Metallurgy is an incredable science but also a bit of a black art much like acoustics. My two cents now in.

Max as the proud owner of an MK47 kit hows those bodies coming along?
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: Winetree on April 11, 2013, 08:44:30 PM
+1 with PIP
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: Marc Duchesne on April 16, 2013, 09:09:28 PM
Moby, I see your point about sharing community, but frankly, there is some limits to invest time into a project and found solutions to problems without a small gratification in the end.  I personally don't have a problem with him not sharing some of this info's. I am happy to pay iaudio money since his selling price is very low for the efforts he is putting into this and I think it is fair. Be careful when you claim he is not sharing because I believe he is sharing a lot already. I agree that you open your own thread about lamination though.
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: liquidify on April 19, 2013, 05:53:02 AM
I think you make some valid points regarding the alloys, as have been adressed in the secondary thread.  However, making a 47 clone does not have to be an exact representation of the original.  There are many reasons for this.  For example, early mics such as the 47 were designed to sound good on tape machines.  For the most part, tape machines are not used today.  There are a substantial number of differences between a recording done on a tape machine vs. one that is not. 

Things like harmonic saturation, tape compression, tape eq, degraded high frequencies, fat ass bass, and many other characteristics are present when tape is used.  Without tape, the microphone and the preamp should be able to do many of these things by themselves, but obviously differently.  Instead of having too much high end to account for tape degradation, a microphone should be just right for digital recordings. 

On the other hand, the U47 did a lot of things better than most other mics throughout history.  The mids were perfect, the casing and body was perfect.  Things like the alloy in the transformer were great, and imparted a significant character to the microphone.

The question that should be asked today is not what the exact technical specs of the original transformer metals were, but what are the exact specs of the transformer metals that will impart the same sweetness as the original metals did, but on digital mediums.  For this reason, knowing the exact specs of the orignial alloys is not only incredibly important, but outright necessary... For someone to build a great microphone with u47 characteristics in todays era, an engineer must not only know what the original alloys were, but know why they were.  They must know how the smallest changes in alloy affect tone, and that is not an easy task.  You need good ears for this, and you need a mind which accounts for factors which the average person does not understand. 

In the end, the perfect transformer for the best digital recordings and even for high frequency DSD, will be different from the original Neumann.  SO, don't despair that this alloy is not exactly the same as the original.  Become a scientist, and examine variables such as when individual metals change as all other variables are the same.  Science is a beautiful thing if applied with a mentality that accounts for the artistic elements. 

Yes, this is important, but your method of encouragement is lacking.  Requiring the gentleman to duplicate the original alloy is neither prudent nor useful for anything other than a starting point.


Alright, so what is going on with the kit?
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: micaddict on April 19, 2013, 06:10:34 AM
Interesting first post.

Anyway, welcome!
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: micaddict on April 19, 2013, 06:21:46 AM
As for contents. I'd agree that the digital medium is different than the old tape setup and that microphones could/should be chosen accordingly. I think this is one of the reasons ribbon microphones have been making a come back, as have tubes and trannies.
But trying to make a clone is trying to make a clone. Not to mention the fact that this one does have a tube and tranny. And back in the seventies when tape was at its prime, no one wanted a (tube) U47.

Another way of looking at it would be getting as close as possible to the sound, but with modern parts. This is considered impossible by many, but some do seriously try. Here's an example. No affiliation and no opinion from me, yet:
http://www.youtube.com/watch?v=9m0B1pKZRT4&feature=youtu.be (http://www.youtube.com/watch?v=9m0B1pKZRT4&feature=youtu.be)
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: Rossi on April 19, 2013, 07:00:12 AM
I wouldn't overstretch the tape vs. digital discussion. A U47 sounds fine on both mediums.

Personally, I don't get the recent obsession with transformer laminations. When we talk about a U47 clone we must consider that the mysterious VF14 tube is unobtanium. As anyone knows, a transformer is only as good as it fits the circuit. So, without the original tube, the original transformer may be optimal anyway. What I really would prefer - this is of course my personal view - is a non-original transformer optimized for a non-original tube that in conjunction come as close as possible to the original combo.

Also, it's been said many times, but I guess it needs repetition: Most of the sound is in the capsule. Anyone not willing to pay top dollars for a genuine Neumann K47 or (working!) Berlin M7 capsule should not worry too much about historically correct laminations. Any capsule substitute is likely to make much more of a difference than the transformer lams. Especially, if we're talking about slight differences as in the above "lamination wars".
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: Biasrocks on April 19, 2013, 09:12:33 AM
I don't agree with your premise. Neumann designed the U47 to sound great using currently available tecnology and materials. I have a bunch of vintage microphones at the studio and never have I chosen a microphone based on whether I was printing to tape or digital.

No one has thrown out their U47's because they don't sound great recorded to digital.

Regards,
Mark

For example, early mics such as the 47 were designed to sound good on tape machines.  For the most part, tape machines are not used today.  There are a substantial number of differences between a recording done on a tape machine vs. one that is not. 
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: liquidify on April 19, 2013, 10:21:43 PM
Interesting first post.

Anyway, welcome!

Thanks for the welcome.  I am a long time lurker.  Figure it was time to talk since I am interested in building this kit.

Any word on developments and release times?
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: Pip on April 20, 2013, 02:03:45 AM
Wow way off topic but.

All that is true and more. The signal chain has changed greatly since the inclusion of these mics into the pantheon of mic lore. No one mic does everything people. The design philosophy behind the inclusion of the VF14 tube was being able to run it on a single supply voltage period (oops I made a verbal punctuation). How else would you explain that when the VF14 tube was no longer available they settled on the Nuvistor?! Wouldn't it have been a lot better, and more responsible to re-tool the mics already in the field and redesign the new ones to accept the EF80 or EF800? The latter being, a lot of people who know a lot more than I do about mic circuitry's, choice for a modern build. The former being a successor tube in the VF, UF and EF14 evolutionary history. Andreas Grosser (a legend in the Neumann community) claims to have a FET solution that plugs directly into a stock VF14 tubed U47 and he dares you to tell the difference. Never ever underestimate a manufacturers (even Neumann) need to meet a market price target!

I agree with Rossi that the capsule is the input and it all begins there just like the lens on a camera.

I have actually heard of people getting rid of there fantastic tube mics for new inclusions into the pantheon for the same reasons that trusted tried and true mics of yore were cast aside due to the "new better ones" coming along. Also in a commercial environment reliability is a must. I have rented vintage gear from reputable sources and had it fail at the worst time. Just because its old.

I myself have fallen back in love with my ribbons and dynamics because of the low noise and expanded dynamic range of digital recording and advancements in preamp architecture.

Transistors vs Tubes, Condenser Mics vs Ribbons and get ready Digital vs Analog. Oye does it sound good do you like what you hear if yes than we all win! 

Another My Two Cents Moment.

Yes Welcome

Yes I want my IOAudio Body Max. But good things come to those who wait. Right?
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: Rossi on April 20, 2013, 03:07:45 AM
Pip, all new U47s had a VF14 tube. The nuvistor was merely a retrofit so users could use a commonly available tube. At the time many studios replaced tubes routinely *before* they would fail in order to avoid troubleshooting during a session.

Of course one of the main motivations behind the VF14 was the single voltage power supply. But that technique led to a quite unique circuit, and since that circuit is so simple, every one of its very few components plays some part in its sound. Apart from that, the VF14 is lower noise than most tubes. Also, there is the underheating aspect - few tubes can stand severe underheating for so long.

Andreas Grosser's FET retrofit seems like cool solution. To my knowledge, he doesn't sell it separately, though.
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: Pip on April 20, 2013, 04:29:29 AM
Pip, all new U47s had a VF14 tube. The nuvistor was merely a retrofit so users could use a commonly available tube. At the time many studios replaced tubes routinely *before* they would fail in order to avoid troubleshooting during a session.

Of course one of the main motivations behind the VF14 was the single voltage power supply. But that technique led to a quite unique circuit, and since that circuit is so simple, every one of its very few components plays some part in its sound. Apart from that, the VF14 is lower noise than most tubes. Also, there is the underheating aspect - few tubes can stand severe underheating for so long.

Andreas Grosser's FET retrofit seems like cool solution. To my knowledge, he doesn't sell it separately, though.

Yes sorry did not mean to imply that a U47 was manufactured new with Nuvistor. Yes the points you make are true about the tubes underheating longevity, it did have a 60v filament! Quiescent electrically yes, but not when comes to microphonics, actually rather lackluster in this respect thus all the internal shockmounting and padding.

Look lets face it good things stand the test of time! No?

I believe Mr. Grosser does sell his VF14ef seperately. But my German stinks so check it out.

 http://www.voxorama.com/service/detail/andreas-grosser-vf14ef.html
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: Rossi on April 20, 2013, 06:31:35 AM

I believe Mr. Grosser does sell his VF14ef seperately. But my German stinks so check it out.

 http://www.voxorama.com/service/detail/andreas-grosser-vf14ef.html

The text states that the VF14ef is not sold separately but can only be ordered as an option when you have your mic repaired or checked by Andreas Grosser.
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: Phrazemaster on April 20, 2013, 01:16:49 PM
Rossi is correct. I have spoken with Andreas many times; in fact he's done work on a microphone of mine. I wanted to build a U47 clone and buy the FET version of the VF14 from him, but he said this is something only he installs personally.

Apparently he used to sell them separately, but he no longer offers this as an option.

HTH,

Mike
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: dandeurloo on April 20, 2013, 02:38:25 PM
Would he install it into your clone?  I'd try that if so.
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: Pip on April 20, 2013, 11:32:05 PM

I believe Mr. Grosser does sell his VF14ef seperately. But my German stinks so check it out.

 http://www.voxorama.com/service/detail/andreas-grosser-vf14ef.html

The text states that the VF14ef is not sold separately but can only be ordered as an option when you have your mic repaired or checked by Andreas Grosser.

Thank You for the translation and forwarding of information. It's a shame as it would be interesting to experiment with this. If anyone contacts him ask about his installing it into a clone. My feeling is that he has his reasons for wanting to implement the install but that doesnt mean he won't sell it for other mics. Maybe?
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: liquidify on April 22, 2013, 06:32:27 AM

I believe Mr. Grosser does sell his VF14ef seperately. But my German stinks so check it out.

 http://www.voxorama.com/service/detail/andreas-grosser-vf14ef.html

The text states that the VF14ef is not sold separately but can only be ordered as an option when you have your mic repaired or checked by Andreas Grosser.

Thank You for the translation and forwarding of information. It's a shame as it would be interesting to experiment with this. If anyone contacts him ask about his installing it into a clone. My feeling is that he has his reasons for wanting to implement the install but that doesnt mean he won't sell it for other mics. Maybe?


I asked Andreas about this.  I am currently buying one of his Voxorama u47's so I have been in frequent contact with him.  He said that if he sees the microphone and all is up to his standards, he would put his vf14ef in it.  He was particularly concerned with the quality of the power supply.  I did not ask him if this offer was something that he would extend to everyone, but I assume it would be.  Andreas seems to be a very nice guy and a person who cares about quality microphones.  He is extremely busy though, and duties to and from Germany are not something to be taken lightly.  I would suggest contacting him personally.
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: ioaudio on April 26, 2013, 07:06:17 AM
just a quick pic of the finished end bells.
(http://www.twin-x.com/groupdiy/albums/userpics/endbells.jpg)
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: pasarski on May 15, 2013, 06:08:46 AM
Any updates about the release schedule?
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: ioaudio on May 16, 2013, 04:48:16 AM
Not as fast as i would like to - but i'm constantly adding new stuff.
Here's the transformer-resistor-cap Pcb assembly:
(http://www.twin-x.com/groupdiy/albums/userpics/trafo_pcb.jpg)
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: micaddict on May 16, 2013, 08:21:24 AM
Quote
Not as fast as i would like to

The problem now of course is
To simply hold your horses
To rush would be a crime
'Cause nice and easy does it every time

(http://static.giantbomb.com/uploads/original/0/9034/2159339-sinatra_studio.jpg)
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: ioaudio on May 16, 2013, 11:43:09 AM
The trafo assembly put in the mic:
(http://www.twin-x.com/groupdiy/albums/userpics/trafo_pcb_assembled.jpg)
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: pasarski on May 16, 2013, 01:38:25 PM
Looks splendid! I'll try to hold my horses, but it's really difficult.
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: Pip on June 01, 2013, 01:40:10 AM
It really is looking quite nice. I have one thought. Would it be possible to leave some more room between the bottom of the Transformer deck and the base of the mic? I would really like to use a PIO can cap here so a bit more room would be nice. Just a thought.

EDIT: I thought a little more. Maybe two mounting choices on the rails one a bit more towards the top of mic.
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: tonycamp on June 01, 2013, 01:53:52 AM
Hey Max, your mic body is looking awesome! i finished your mk47, i can't thank you enough, it sounds incredible, i used a gt2B donor, but the mic sounds so fantastic, it's a sin not housing her in a swimsuit body! i want to be put on what ever list is necessary to buy one of your forthcoming 47 bodies

thanx
T
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: evilcat on June 02, 2013, 05:48:50 AM
Hi Max,

This looks incredible! I'm just about to build my 1st microphone and would be very interested by a 47. I think I'll wait some sort of kit of your PCB, transformer, parts and body!!!
Keep going man, your project looks amazing.

Best,

Ben
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: micaddict on June 02, 2013, 07:57:42 AM
This one will be point-to-point, so no PCB.
Well, it's not forbidden, of course.
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: evilcat on June 02, 2013, 09:24:13 AM
Ah ok... P2P sounds cool to me ! Could be fun.
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: Woot on June 02, 2013, 07:50:42 PM
Looks amazing, I'm in for one  8)
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: rainton on June 10, 2013, 08:14:46 PM
Wow!! I'm so subscribing to this thread  ;)
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: rainton on June 11, 2013, 08:35:05 PM
Hey Max,
I'm really interested in one of your kits when it's ready - put me on the list - looks like an amazing project :)

Can you share some more details on the twin-tube design as a replacement for one VF14?
Sorry if that has been answered elsewhere before - I couldn't find it...
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: nashkato on June 12, 2013, 10:10:08 AM
here you go
http://www.groupdiy.com/index.php?topic=41379.0
the tubes are 6028 eqivalent : 408A iirc
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: rainton on June 13, 2013, 09:50:42 AM
here you go
http://www.groupdiy.com/index.php?topic=41379.0
the tubes are 6028 eqivalent : 408A iirc

Thanks! :)
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: tonycamp on June 19, 2013, 12:20:01 AM
Hey Max, it's been a month with no update, i'm dying to give you my $!!! ;D
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: micaddict on June 19, 2013, 05:33:58 AM
Max took a well deserved vacation that ends today as a matter of fact.  :)
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: ioaudio on June 20, 2013, 03:56:48 AM
And back i am, relaxed and ready to continue the work  :)
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: rainton on June 20, 2013, 08:49:11 PM
And back i am, relaxed and ready to continue the work  :)

Yeah ride on  :D
Any idea when it'll be ready?
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: tskguy on June 21, 2013, 06:46:08 PM
Ok so I have built a pair of G7's 4 custom ribbon mic's, 3 u87's, a u67 with one of Max's transformers,
a 47 fet and now i am working on M49. I have honestly been waiting on building a U47 because I haven't felt like anyone in the DIY world has really nailed the body, UNTIlL NOW!!! These are going sweet!!!! Max great job, but please hurry!!  I am steadily losing patience  ;D
Tskguy
Title: Re: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: ioaudio on June 24, 2013, 09:07:58 AM
And for those of you hoarding the vf14 tubes: Plug and play with either the original telefunken or my vf14r version (prototype shown).
(http://www.twin-x.com/groupdiy/albums/userpics/vf14_vf14r.jpg)
(http://www.twin-x.com/groupdiy/albums/userpics/normal_vf14_comp.jpg)(http://www.twin-x.com/groupdiy/albums/userpics/vf14er_comp.jpg)
Title: Re: U47 Clone from scratch: MK-U47
Post by: EvLoutonian on June 24, 2013, 09:33:29 AM
Bring it on.
Title: Re: U47 Clone from scratch: MK-U47
Post by: Dr Gris on June 24, 2013, 09:39:54 AM
Aha!!
That answers my question in reply#50 in this thread.
I felt you had something going on. Fantastic!!

Best
Magnus
Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on June 24, 2013, 09:44:54 AM
looking great!!  8)
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on June 25, 2013, 10:00:30 AM
The High-Z board made from Makrolon, holding the very high impedance sections of the circuit and capsule connections.
(http://www.twin-x.com/groupdiy/albums/userpics/Hz-Board.jpg)
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on June 25, 2013, 10:15:47 AM
mounted on the capsule mounting disc:
(http://www.twin-x.com/groupdiy/albums/userpics/Hz-Board_mounted.jpg)
Title: Re: U47 Clone from scratch: MK-U47
Post by: evilcat on June 25, 2013, 10:18:24 AM
That's just beautiful!!!
Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on June 25, 2013, 10:25:40 AM
amazing aka  voi leiwand!!  ;)
Title: Re: U47 Clone from scratch: MK-U47
Post by: micaddict on June 25, 2013, 10:31:37 AM
I gotta get out of this place.
Title: Re: U47 Clone from scratch: MK-U47
Post by: DjaiTeam on June 28, 2013, 04:32:32 PM
Hi Max, will the psu for this project be the same as Zayance's psu pcb?

Btw, was waiting for this project. More pics and prices plz  ;)

Regards,
Iwan
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on June 29, 2013, 11:15:18 AM
Thanks guys, and sry it's taking longer than expected.
Iwan, yes the Psu is compatible to the MK47 PCB project and to the original Neumann U47 Psu.





Title: Re: U47 Clone from scratch: MK-U47
Post by: micaddict on June 29, 2013, 11:53:42 AM
How cool is that!

Thanks for sharing, Max.



Henk
Title: Re: U47 Clone from scratch: MK-U47
Post by: SGare on June 30, 2013, 08:04:12 AM
Very Impressed

I should imagine getting the balance of the right metals and the critical temps in the construction of this transformer effects the final sound.

if you get it the right balance then the sound will be the same..... got to be (transformer wise as the original).

Are you testing your transformers inside an original u47 setup against the original transformer?

Steve
Title: Re: U47 Clone from scratch: MK-U47
Post by: 0dbfs on July 01, 2013, 01:08:49 PM
Quote
Sample 1 to 7 where used in original Bv.08, Bv.11 and Bv12 transformers.

Max, Could you possibly be convinced to do a run of BV11's?

Cheers,
jb
Title: Re: U47 Clone from scratch: MK-U47
Post by: tskguy on July 01, 2013, 02:14:06 PM
Quote
Sample 1 to 7 where used in original Bv.08, Bv.11 and Bv12 transformers.

Max, Could you possibly be convinced to do a run of BV11's?

Cheers,
jb

I second that request!!!
 ;D
I actually just pulled the trigger on a Huafe BV11 but having a Max version would be ideal!


Eric
Title: Re: U47 Clone from scratch: MK-U47
Post by: DjaiTeam on July 02, 2013, 02:13:02 AM
Hi Max, which tubes you are going to use in your vf14r in post nr 156?
Sorry, i'am new here. I can get my hands on some telefunken tubes but do not know which one to get for this project.

Regards,
Iwan
(Edit) found my answer in previous thread  :)
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on July 02, 2013, 12:26:31 PM
>>Are you testing your transformers inside an original u47 setup against the original transformer?

I do have the circuit on the bench (in a mu-metal housing) for testing.

>>Max, Could you possibly be convinced to do a run of BV11's?

Yes, absolutely, i will add this to my store soon, wound with 8 chambers like the original of course.
Title: Re: U47 Clone from scratch: MK-U47
Post by: dmp on July 02, 2013, 01:14:25 PM
Quote
>>Max, Could you possibly be convinced to do a run of BV11's?
Yes, absolutely, i will add this to my store soon, wound with 8 chambers like the original of course.

Very cool! Possible to make sure they are size and pin compatible with Poctop's M49 PCBs?
http://www.groupdiy.com/index.php?topic=49675.0
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on July 03, 2013, 05:57:00 AM
>>Bv11 - Very cool! Possible to make sure they are size and pin compatible with Poctop's M49 PCBs?

The size will be the same as the original Bv.11 - the transformers used in poctop's pcb have a different size...

-max
Title: Re: U47 Clone from scratch: MK-U47
Post by: poctop on July 03, 2013, 08:18:07 AM
>>This kind of alloys typically contains from 1-2% impurities.

No, more like (ballbark figures) >= 0.05% C , >= 0.005% P, >= 0.005% S and some 0.1%to 0.2% Si

>>Bv11 - Very cool! Possible to make sure they are size and pin compatible with Poctop's M49 PCBs?

The size will be the same as the original Bv.11 - the transformers used in poctop's pcb have a different size...

-max

Hi Max what is the dimension of your upcoming BV11 , i and if you would have a pinout and dimension drawing i could look into that ,
Let me know,
Best,
Dan,

Title: Re: U47 Clone from scratch: MK-U47
Post by: scott_humphrey on July 03, 2013, 08:59:03 AM
Moby/Dobrilo,

Your knowledge regarding the lams is impressive, but I come to this thread to see how the mic project is progressing. This is Max's thread. Please don't be a rude guest. Enough already. Go to the other thread to post your information. It's interesting stuff. I will read it there.

Jim Marshall didn't copy the '59 Bassman exactly. Instead, he used the tubes and transformers that were available to him in England and created the Marshall amp. Did it sound exactly the same as the Fender? No, but it was equally as good, just different.

We are faced with a similar situation. We don't have the exact capsules, transformers, and tubes to create a perfect Neumann replica, but there is no need to fret. If we have good ears and tune the circuit based around the capsules, tubes, and transformer that we have at our disposal, we should all be able to end up with a mic that has it's own character but is outstanding in its own way.
Title: Re: U47 Clone from scratch: MK-U47
Post by: poctop on July 03, 2013, 11:02:25 AM
the pinout will be the same as the bv12 pinout minus the 4 outer pins - i will publish the bv11 pinout soon.

Just PMed you for details.
Best,
Dan,
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on July 03, 2013, 11:16:50 AM
the bv11 pinout:

(http://www.twin-x.com/groupdiy/albums/userpics/Bv11_pinout.jpg)
Title: Re: U47 Clone from scratch: MK-U47
Post by: Pip on July 05, 2013, 12:01:39 AM
Max by the way I want one for sure the only thing that can stop me now is you and lack of currency. I will keep up my end!  ;)
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on July 05, 2013, 12:40:35 PM
Edit:
I'll delete all my posts regarding the alloy topic and would like to ask you, moby, and you, Dobrilo, to do the same, please.
You can start a new topic and move the discussion there.
thanks,
max
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on July 08, 2013, 06:13:32 PM
Everything wired but the capsule and connector:



(http://www.twin-x.com/groupdiy/albums/userpics/wired.jpg)(http://www.twin-x.com/groupdiy/albums/userpics/wired2.jpg)
Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on July 08, 2013, 06:20:26 PM
Oh yeah!!   :D
Title: Re: U47 Clone from scratch: MK-U47
Post by: Pip on July 08, 2013, 11:03:18 PM
 :) ;) :D ;D >:( :( :P :-* :'(



It sent me through all kinds of feelings. This is bordering on pornographic!

It truly looks gorgeous. Well done.
Title: Re: U47 Clone from scratch: MK-U47
Post by: evilcat on July 09, 2013, 04:17:07 AM
Oh my !!!!! this is too cool !!!!!!
Title: Re: Neumann U47 Replica: MK-U47 Brass Mic Body & New Bv.08 Transformer
Post by: o3misha on July 09, 2013, 06:48:51 AM
Pip, all new U47s had a VF14 tube. The nuvistor was merely a retrofit so users could use a commonly available tube. At the time many studios replaced tubes routinely *before* they would fail in order to avoid troubleshooting during a session.

Of course one of the main motivations behind the VF14 was the single voltage power supply. But that technique led to a quite unique circuit, and since that circuit is so simple, every one of its very few components plays some part in its sound. Apart from that, the VF14 is lower noise than most tubes. Also, there is the underheating aspect - few tubes can stand severe underheating for so long.

Andreas Grosser's FET retrofit seems like cool solution. To my knowledge, he doesn't sell it separately, though.
1. Talk to Andreas about his VF14er. Its the tube which can work in U47 without modifications.
2.Its not true that VF14 is less noisy than other tubes
http://www.andreas-grosser.com/profile/interview-with-andreas-grosser/
3. VF14EF is possible to buy when you send your U47/48 to Andreas for repair.
Title: Re: U47 Clone from scratch: MK-U47
Post by: tonycamp on July 10, 2013, 02:43:52 AM
max, that is a thing of beauty! any idea when she'll be available for purchase, and how much?

I said it before, and i'll say it again, I'm dying to give you my money!!!
Title: Re: U47 Clone from scratch: MK-U47
Post by: fishdrop on July 12, 2013, 05:00:03 PM
Woooooooooow. DIY is a crazy virus, isn't it!!!!

 :D

really infecting.
Can't wait to see the ready-to-go  kit.
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on July 13, 2013, 10:10:19 AM
Thanks guys.
And sry it's taking longer.
Instead of making vague assumptions about the timeline to finally release this project (and it's pricing) i thought i better post pics of the progress.

Title: Re: U47 Clone from scratch: MK-U47
Post by: JW on July 15, 2013, 03:45:19 PM
I imagine this question has been asked before. If so, can someone direct me to where it's been discussed.

Just wondering what the difference is between this transformer and the one Max was/is offering w/ the MK47 kit?
Title: Re: U47 Clone from scratch: MK-U47
Post by: Pip on July 15, 2013, 09:18:25 PM
I imagine this question has been asked before. If so, can someone direct me to where it's been discussed.

Just wondering what the difference is between this transformer and the one Max was/is offering w/ the MK47 kit?

This one was built I believe by AMI in Kansas to Oliver Archut's measured spec's.

http://tab-funkenwerk.com/id53.html

Max's is built by him in Austria to his measured spec's.

http://www.groupdiy.com/index.php?topic=35667.0
Also Max's comes usually as part of a kit and is PC mounted were Olivers is a classic type with leads. I own one of each and they are both class kit!
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on July 19, 2013, 08:34:05 AM
Pip, i'm pretty shure that you mixed up something, both transformers are made by me.
The Bv.08c from the Mk47 Kit is made from the same lamination footprint, but lower stack height to fit the smaller housings.
My new Bv.08 is full size, full stacked height and wound on 4 seperated chambers per coil (eight chambers total) just like the original Neumann Bv.08.
Title: Re: U47 Clone from scratch: MK-U47
Post by: Pip on July 19, 2013, 08:42:26 PM
Pip, i'm pretty shure that you mixed up something, both transformers are made by me.
The Bv.08c from the Mk47 Kit is made from the same lamination footprint, but lower stack height to fit the smaller housings.
My new Bv.08 is full size, full stacked height and wound on 4 seperated chambers per coil (eight chambers total) just like the original Neumann Bv.08.


OOOOOOPPPPPS I totally screwed up you are correct I thought I was in another thread. My appologies. I thought I was in Melodeaths thread. Man I suck!

Yes Max does make both and they are awesome. I only own the one of his. The MK47 and it is awesome. I totally plan on buying this one when he is done.

 I will do what ever the community wants. Leave my Dumbness for all to see and learn from as I did or remove it and cast it into the ever growing cyber abbyss for all time. Max I will do what ever you desire.

Has a similar feeling to totally botching a punch-in. Argh!
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on July 20, 2013, 11:32:16 AM
No worries, everyone can see that it's just a mixup.
Title: Re: U47 Clone from scratch: MK-U47
Post by: Citrus Hill on August 09, 2013, 11:38:21 PM
I'd like to get on the list for a pair of these if possible.  Looking forward to seeing the finished product.  Anything worth having is worth waiting for!
Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on August 10, 2013, 03:54:38 AM
I'd like to get on the list for a pair of these if possible.  Looking forward to seeing the finished product.  Anything worth having is worth waiting for!

Indeed!
BTW any news Max?   ;)
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on August 22, 2013, 11:52:50 PM
Just to chime in again...lovin' this project! Put me down for one max!

Any thoughts as to when this will be ready? :)
Title: Re: U47 Clone from scratch: MK-U47
Post by: ArnoldLayne on August 23, 2013, 09:13:37 PM
I want one too !  :o
Title: Re: U47 Clone from scratch: MK-U47
Post by: Randallizer on September 07, 2013, 01:11:37 PM
I'd love to put my name down for one of these if possible. It's a really lovely project!
Title: Re: U47 Clone from scratch: MK-U47
Post by: North on September 08, 2013, 02:21:51 PM
What would be the sound and output difference in using the full stack height compared to the lower stack height ? Thanks
Title: Re: U47 Clone from scratch: MK-U47
Post by: wolfgang on September 24, 2013, 04:19:16 AM
Hello Max!

Can you give us an update on your progress?
I am highly interested!!!!!

regards from Styria!

Wolfgang
Title: Re: U47 Clone from scratch: MK-U47
Post by: Brotastic on September 25, 2013, 01:59:21 AM
me three!!!  very interested
Title: Re: U47 Clone from scratch: MK-U47
Post by: tonycamp on September 25, 2013, 12:15:24 PM
its been just over 2 months since  max has chimed in on this? i know he's been around, i think he's playing hard to get ;)
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on October 05, 2013, 11:25:32 PM
From the looks of his other offerings, it seems he has been quite busy fulfilling many other orders! Like sending me a BV11 for an M49 I'm going to build.

I'm sure this kind of thing takes some time to develop and do right...:)

Thanks Max for your awesome products!

Mike
Title: Re: U47 Clone from scratch: MK-U47
Post by: Aaronrash on October 05, 2013, 11:49:09 PM
Count me in for one as well when they become available
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on October 06, 2013, 12:52:09 AM
And for the record, in case it wasn't clear, me too!
Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on October 06, 2013, 07:45:12 AM
Yes and "just for the records" I'm also in for 2 ;)

Title: Re: U47 Clone from scratch: MK-U47
Post by: reginator on October 19, 2013, 09:22:10 AM
Hi everyone! I'm new here and new to mic building, but not new to electronics; having slaved over a soldering iron at a Scientific Atlanta lab in the past.

I've read the U47 is a superb vocal mic and I'm really looking forward to building the MK-U47! I guess I'll build the power supply too!  ;)

Cheers!
Reggie
Title: Re: U47 Clone from scratch: MK-U47
Post by: reginator on October 20, 2013, 01:21:52 AM
Oh, and please include me in the list too!  :)
Title: Re: U47 Clone from scratch: MK-U47
Post by: duantro on October 27, 2013, 02:57:05 AM
Beautiful work Max! Can't wait for this to become available!
Title: Re: U47 Clone from scratch: MK-U47
Post by: OPR on November 07, 2013, 09:47:10 PM
Wow such beautiful work!! I want two!
Title: Re: U47 Clone from scratch: MK-U47
Post by: Pip on November 12, 2013, 10:45:37 PM
BUMP! What's up with this thing of beauty?!
Title: Re: U47 Clone from scratch: MK-U47
Post by: electrisizer on November 13, 2013, 12:21:43 PM
 :D im asking too
have a thiersch blue line searching for a new home  :'(
Title: Re: U47 Clone from scratch: MK-U47
Post by: Category 5 on November 13, 2013, 02:55:29 PM
Wow.  Sign me up for one.  This looks just superb!  Now I know what do do with my  thiersch blueline!
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on November 14, 2013, 12:13:23 PM
Thank you guys,

and sorry, i know a update is way overdue.

Besides the additions to my transformer shop - as mentioned the Bv.11 and recently the Bv.08  - i spend a lot of time trying to re-create the M7 Capsule.
Although i progressed quite a bit, i still can't control all parameters in production to go for series production.
I decided to build a small but precise lathe with a  build-in drilling head to be able to do the operation on one machine, but that will take some time.
So in my first batch of Mk-U47 no capsule will be included and i recommend the Thiersch Blue line.

Did you guys order the capsule with it's holder included? If so, which height did you choose?

The housing is coming along slowly but nicely and i'm still hoping to be able to release the kit in late 2013.
The finish still needs to be done, and i'm particularly picky about the bead blasting and the galvanic treatment.
But that's where the use of brass pays off, i hope the end-result will be really nice.

-Max



Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on November 14, 2013, 12:37:50 PM
Yeeaah - sounds like Christmas is getting closer!!!  ;D
Title: Re: U47 Clone from scratch: MK-U47
Post by: Category 5 on November 14, 2013, 01:45:14 PM
Thank you guys,

and sorry, i know a update is way overdue.

Besides the additions to my transformer shop - as mentioned the Bv.11 and recently the Bv.08  - i spend a lot of time trying to re-create the M7 Capsule.
Although i progressed quite a bit, i still can't control all parameters in production to go for series production.
I decided to build a small but precise lathe with a  build-in drilling head to be able to do the operation on one machine, but that will take some time.
So in my first batch of Mk-U47 no capsule will be included and i recommend the Thiersch Blue line.

Did you guys order the capsule with it's holder included? If so, which height did you choose?

The housing is coming along slowly but nicely and i'm still hoping to be able to release the kit in late 2013.
The finish still needs to be done, and i'm particularly picky about the bead blasting and the galvanic treatment.
But that's where the use of brass pays off, i hope the end-result will be really nice.

-Max

Do you have any idea of the initial quantities or ballpark pricing yet.  Very keen to get in on this one.

Title: Re: U47 Clone from scratch: MK-U47
Post by: zamproject on November 14, 2013, 02:13:58 PM
never post on this one... but i follow since beginning!!!

I already have 2 MK47 with Equinox body, but for sure i will go for two of this one!!!
and 2 or 3 more for friend's group buy.
so count me for 4 pces minimum  :)

any price range idea?

Zam
Title: Re: U47 Clone from scratch: MK-U47
Post by: ciscan.81 on November 14, 2013, 06:52:45 PM
Hi All

I've built a ribbon mic from scratch in the past but I'm currently researching a couple of tube mic builds: A _C12 and a _U47...

Looks like the search for the _U47 project ends here. Brilliant work Max.

Please count me in for one.

Finally, apologies if this covered elsewhere or is a stupid question; but I see that the 6028/408a is recommended for the MK47 build...will the same tubes be utilised in this project?

very very exciting! I love building stuff!!! huzzah :D
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on November 15, 2013, 05:05:38 AM
Thank you guys,

and sorry, i know a update is way overdue.

Besides the additions to my transformer shop - as mentioned the Bv.11 and recently the Bv.08  - i spend a lot of time trying to re-create the M7 Capsule.
Although i progressed quite a bit, i still can't control all parameters in production to go for series production.
I decided to build a small but precise lathe with a  build-in drilling head to be able to do the operation on one machine, but that will take some time.
So in my first batch of Mk-U47 no capsule will be included and i recommend the Thiersch Blue line.

Did you guys order the capsule with it's holder included? If so, which height did you choose?

The housing is coming along slowly but nicely and i'm still hoping to be able to release the kit in late 2013.
The finish still needs to be done, and i'm particularly picky about the bead blasting and the galvanic treatment.
But that's where the use of brass pays off, i hope the end-result will be really nice.

-Max
Why the blue line Max? Andreas Grosser recommends the red line himself, at least he did to me over the phone. I guess I'm concerned over long term stability due to the PVC degradation over time...Is the sound superior in some way to the red line mylar version? Thoughts?

Thanks, and I'm looking forward to your kit!

Mike
Title: Re: U47 Clone from scratch: MK-U47
Post by: ciscan.81 on November 15, 2013, 05:31:25 AM

Quote
Why the blue line Max? Andreas Grosser recommends the red line himself, at least he did to me over the phone. I guess I'm concerned over long term stability due to the PVC degradation over time...Is the sound superior in some way to the red line mylar version? Thoughts?

Thanks, and I'm looking forward to your kit!

Mike
Without wanting to flood this thread with a PVC vs Mylar debate:

+1 on this question...

I'm having a hard time deciding which way to go... :-\

I've read far and wide. There is a good discussion here on the topic between some notable mic gurus...

http://repforums.prosoundweb.com/index.php?topic=28330.0
 (http://repforums.prosoundweb.com/index.php?topic=28330.0)

but the jury still seems to be out...
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on November 15, 2013, 05:54:13 AM
Well, I appreciate that...I've done research on it too; I guess I'm just wondering why Max in particular is suggesting the blue line.
Title: Re: U47 Clone from scratch: MK-U47
Post by: Category 5 on November 15, 2013, 08:01:03 AM
Well, I appreciate that...I've done research on it too; I guess I'm just wondering why Max in particular is suggesting the blue line.

Same reason they sell the blue line.  Historical accuracy and slight variation in tone.  Nobody ever said PVC will "degrade" over time.  Most people thought the older capsules sounded just fantastic so think of it like win that matures and improves with age rather than degradation.  The M7 was the original capsule and it was PVC.

I'm sure the red will be a fantastic option for folks that are worried about the change in sound, but keep in mind those can change too.  I am pretty sure the difference is that the PVC will tighten over time while the PET will loosen.  If you plan to use the mic in scenarios where very low end cent will be important than maybe the red is the way to go.
Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on November 15, 2013, 08:14:41 AM
Well, I appreciate that...I've done research on it too; I guess I'm just wondering why Max in particular is suggesting the blue line.

Same reason they sell the blue line.  Historical accuracy and slight variation in tone.  Nobody ever said PVC will "degrade" over time.  Most people thought the older capsules sounded just fantastic so think of it like win that matures and improves with age rather than degradation.  The M7 was the original capsule and it was PVC.

I'm sure the red will be a fantastic option for folks that are worried about the change in sound, but keep in mind those can change too.  I am pretty sure the difference is that the PVC will tighten over time while the PET will loosen.  If you plan to use the mic in scenarios where very low end cent will be important than maybe the red is the way to go.

Well I also tried to find as much as possible on this topic and a lot of sources said PVC will "degrade" over time (i.e. K.Heyne, A. Grosser, etc.) :-\
And also explained how it happens and what it does to the sound (loss of low end; noise)

But I'm with the others that still couldn't make up their mind or get a clear picture of what to use.
And it's not true that all M7s were made of PVC, right - Neumann stopped using PVC in 1957 in favor for MCF (Macrofol) which is basically also PE like Mylar.
The only thing I know after reading all the articles is that it is clearly a matter of taste, too.
Anyway I guess the only way to find out for yourself is get both and hear them "side-by-side" under the same conditions - that's probably what I'll do  ::)
Title: Re: U47 Clone from scratch: MK-U47
Post by: electrisizer on November 15, 2013, 08:34:13 AM
i read that blue line has bit smoother highs than red line - for a vocal mic i need smoothness. german singers tend to emphasize SSSSS and its difficult to remove after recording without sounding dull.
on the other hand its a pleasure to boost highs when they are smooth and open with a good EQ - thats the way i prefer. same thing for overheads...  :)
Title: Re: U47 Clone from scratch: MK-U47
Post by: Melodeath00 on November 15, 2013, 09:51:43 AM
FWIW, I have read Oliver say that only the blue line is "up to snuff," (my quotes, not his words) but that may have been an old comment, and I believe the red line/mylar may have gone through some different iterations/versions over time. Regardless, they use the blue line in the Lucas CS-4. If I were to replace the BeesNeez K7 in my mic, it would be with a blue line. In fact, I may do that anyway once I build a U47 FET.

EDIT: I found the post from Oliver I was thinking of, and indeed it was from 2008, and before he had even heard the PVC blue line. Regardless, he said the Thiersch mylar "did not cut it." Honestly, this may have even been before they were called blue and red. Regardless, I think the fact that they use the blue in the Lucas says something. I would go for PVC for authenticity, but that's me.
Title: Re: U47 Clone from scratch: MK-U47
Post by: chefducuisine on November 15, 2013, 02:35:23 PM
Max,

no need to hurry - as we say: 'Gut Ding will weile haben...'
Thiersch states that the correct holder for an M7 is the STS 7a. Look at the third picture on Products/Holder STS 7, the last column mentions the microphone.

If you didn't have already - put me on the list for at least one.

Regards,

Christian
Title: Re: U47 Clone from scratch: MK-U47
Post by: Dr Gris on November 15, 2013, 03:41:19 PM
I have an old M7 PVC (original, not a Thiersch Blue Line) and it has sure "degraded" over the
years, and is noisy. Thinking of having it reskinned with PVC again, but I'm not sure.
I have an original U47 with another original M7 (see reply #50 in this thread ;))
reskinned by Thiersch with Mylar, sounds darn good to me....

Best
//M
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on November 15, 2013, 03:48:03 PM
I have an old M7 PVC (original, not a Thiersch Blue Line) and it has sure "degraded" over the
years, and is noisy. Thinking of having it reskinned with PVC again, but I'm not sure.
I have an original U47 with another original M7 (see reply #50 in this thread ;))
reskinned by Thiersch with Mylar, sounds darn good to me....

Best
//M
Thanks for chiming in Dr Gris! Now I'm only completely confused.  :o  lol seriously thx.
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on November 16, 2013, 11:21:01 AM
Re: Why i recommend the blue line:
In the past i remmended Thiersch's capsules with no preference, but i had three or more users changing to PVC after purchasing the PE red line capsule in the first place.
I'd say overall the feedback was better regarding the PVC capsule.

Re: Capsule holder:
The STS7 is available in three different heights 52, 55 and 58 mm - i was wondering which one most people here bought.

Title: Re: U47 Clone from scratch: MK-U47
Post by: Pip on November 16, 2013, 12:36:34 PM
I hope this does not start a flood. But I bought a Blue Line only as a nod to antiquity and authenticity when it comes to originality. The Red line is just as good. If you read the info on the Thiersch site it is stated that sonically they can detect no difference (with the equipment they own) they only started making the PVC membrane capsule because of customer demand due to a move towards original authenticity not sonic variance. I will also be buying a red line for other mic projects. I actually go with Mr. Grosser on this even though I decided differently. If you want a mic that will stay healthier longer, buy the Red Line.


 http://www.thiersch-mic.de/en/estm_ablauf.html
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on November 16, 2013, 04:51:02 PM
Thanks Max and Pip for adding to this. I didn't mean to hijack the thread getting on about this, but since it was brought up I thought to ask for clarification.

Thanks much,

Mike
Title: Re: U47 Clone from scratch: MK-U47
Post by: ciscan.81 on November 16, 2013, 05:59:09 PM
Thanks everyone for the red/blue info...it all helps when trying to chose 'sound un-heard'...

On another topic...

Max (or anyone else thar knows) what tubes are you recommending for this project? 6028/408a as per the MK47?

I know this was touched on earlier in the thread, but I'm still not clear.

I'm in the process of ordering some tubes for a couple of other projects and would like to order them all at once if I can.

Thanks
Title: Re: U47 Clone from scratch: MK-U47
Post by: Nele on November 17, 2013, 06:31:17 AM
Re: Capsule holder:
The STS7 is available in three different heights 52, 55 and 58 mm - i was wondering which one most people here bought.

For my Skylar-body rendition of your mk7 I used the 58mm version. This places the capsule above the center of the headbasket, as was originally the case. You could always choose a version and use acrylic spaceplates to raise or lower the capsule.
Title: Re: U47 Clone from scratch: MK-U47
Post by: Le Roux on November 17, 2013, 10:13:19 AM
STW 7.1 - Blue & STS 7.1b 52 mm and the D7.1

"We have only STS 7.1b in stock. The mount is with transducer and head/roof 52mm high."
(http://)
Title: Re: U47 Clone from scratch: MK-U47
Post by: sr1200 on November 18, 2013, 12:15:52 PM
I was about to start my own u47 project using the nuvistor circuit.  This looks like its gonna beat the snot out of what i was planning.  Is there a list i can get on?
Title: Re: U47 Clone from scratch: MK-U47
Post by: ciscan.81 on November 18, 2013, 08:29:06 PM
...For anyone else who needs something to help tip their scales regarding the capsule choices...

I sent a PM to a GDIY member who built 3 MK47's (in a couple of different bodies). He used 3 different capsules: a Theirsch Blue line, Theirsch Red Line and BeezKneez M7.

I asked if after 6 months with the three mics he had a preference, his response:

Quote
If i had to buy another capsule now I would still get the Blue line.  It just has a sound I prefer overall.  It is subtle but I do prefer it.

Obviously there are other variables (eg. BeezKneez was in different body to the 2 Theirschs) and it is just one guys opinion/taste...BUT with all my other research, it was just enough to help me settle on a choice...FINALLY!  ;D


Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on November 18, 2013, 09:33:03 PM
...For anyone else who needs something to help tip their scales regarding the capsule choices...

I sent a PM to a GDIY member who built 3 MK47's (in a couple of different bodies). He used 3 different capsules: a Theirsch Blue line, Theirsch Red Line and BeezKneez M7.

I asked if after 6 months with the three mics he had a preference, his response:

Quote
If i had to buy another capsule now I would still get the Blue line.  It just has a sound I prefer overall.  It is subtle but I do prefer it.

Obviously there are other variables (eg. BeezKneez was in different body to the 2 Theirschs) and it is just one guys opinion/taste...BUT with all my other research, it was just enough to help me settle on a choice...FINALLY!  ;D
I already have a U47 clone in the making and I have a red line. For me it makes sense to venture into blue territory lol...although I'm a little disappointed we never really heard of the fruits of Klaus' collaboration with Thiersch or if they ever really bore fruit...I'm game to try blue this time.

Thanks for the sharing ciscan

Mike
Title: Re: U47 Clone from scratch: MK-U47
Post by: benqbasic on November 20, 2013, 11:27:59 PM
Everything wired but the capsule and connector:



img]http://www.twin-x.com/groupdiy/albums/userpics/wired2.jpg[/img]

Hey Max,
I've just noticed your using what looks like K42Y capacitors. I haven't seen them come up in discussion about the U47 although i have used them in non-mic circuits. Did you select these capacitors for sonics?

Cheers
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on November 22, 2013, 10:55:08 AM
Re: tubes for in the MK-U47

I still like the simplicity of the one-supply solution with two 6028 tubes.
Plug and Play compatibility with VF14 tubes makes this solution attractive to those lucky enough to own one.

Additionally i decided to open the system to work with other tubes by optionally adding a seperate heater supply.
The MK-U47 can be used with various tubes - steel types (eg. EF12, EF12k, EF14) or one of the wide variety of glass tubes - in many configurations (self biased, forced bias or fixed bias)

Re: height of the capsule holder
Thanks for the stock update, seems i will have to include acryl spacers for different holder types/heights.

Re: capacitors

Yes, I'll include K42Y caps as filter and output capacitor - i like them and i saw them in various high-end U47 clones.

-max
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on November 22, 2013, 02:41:05 PM
This is getting exciting Max! Can't wait!
Title: Re: U47 Clone from scratch: MK-U47
Post by: Woot on November 22, 2013, 08:32:52 PM
This is getting exciting Max! Can't wait!

Absolutely! Can't wait. I'm in for 1.

 8)

Thanks Max
Title: Re: U47 Clone from scratch: MK-U47
Post by: tonycamp on December 05, 2013, 10:57:19 PM
all the talk about the blueline...here is my 2 cents..

I have a beeznees K7, M7, Thiersch blueline, i've tried all of them in my mk47 for extended periods, the blueline resides in the 47 now and for good, there is no doubt in my mind it's the best capsule for this mic.
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on December 06, 2013, 01:22:27 AM
all the talk about the blueline...here is my 2 cents..

I have a beeznees K7, M7, Thiersch blueline, i've tried all of them in my mk47 for extended periods, the blueline resides in the 47 now and for good, there is no doubt in my mind it's the best capsule for this mic.
Tony, thanks for the feedback. What do you like better about the blueline vs all the rest?

Thanks,

Mike
Title: Re: U47 Clone from scratch: MK-U47
Post by: tonycamp on December 06, 2013, 01:58:58 AM
all the talk about the blueline...here is my 2 cents..

I have a beeznees K7, M7, Thiersch blueline, i've tried all of them in my mk47 for extended periods, the blueline resides in the 47 now and for good, there is no doubt in my mind it's the best capsule for this mic.
Tony, thanks for the feedback. What do you like better about the blueline vs all the rest?

Thanks,

Mike

I've thought about how to describe it without sounding like a cliche...not easy lol
i guess i would say there is a focused smoothed 3d character that none of the others had, very easy on the S's and T's, definitely not lurchy and zing free on the top, with no jumpy whoomph on the low mid down, these attributes excelled to different degrees beyond the others to my ears, it sounds more "comfy" and sits like a record without twisting any knobs? I guess the bottom line is it sounded the most like my idea of a U47.

What was unexpected is just how different all the capsules sound from one to the next, i figured subtle diffs
I put the K7 in a multi pattern schoeps fet mic, it sounds really good there, but the mk47/blueline is just magic imo.
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on December 06, 2013, 02:05:25 AM
Thanks Tony, very helpful!
Title: Re: U47 Clone from scratch: MK-U47
Post by: frans on December 21, 2013, 02:42:37 PM
I was wondering what elastic suspension would go well with this. What about the Peluso for the 47? Does look unquestionable chinese.
http://www.pelusomicrophonelab.com/parts/Mounts.html
Title: Re: U47 Clone from scratch: MK-U47
Post by: monkeyxx on December 21, 2013, 02:49:56 PM
I was wondering what elastic suspension would go well with this. What about the Peluso for the 47? Does look unquestionable chinese.
http://www.pelusomicrophonelab.com/parts/Mounts.html

You can get the same mounts without the Peluso name MUCH cheaper from various sellers on ebay for example, I think one guy is called Q Mic he's a US seller, has a website I believe.  I only paid $20ish if I remember right, for my C12/251 size mounts that look just like the Peluso in person, maybe different color elastic.
Title: Re: U47 Clone from scratch: MK-U47
Post by: fishdrop on December 21, 2013, 03:45:48 PM
i'm wondering how much diameter the clone's gonna have? short or ong body?
a standard u47 has 60 mm (short body) or 63 mm (long body)

found that one on ebay
http://www.ebay.de/itm/141036077571?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

it can handle mics with up to 63 mm.
should be fine.
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on December 22, 2013, 09:27:48 AM
The body tube is 60mm for the short and the long body. 63mm is the biggest diameter of the head basket.

Unfortunately the housing is still not finished and the release will be postboned to 2014.

-Max
Title: Re: U47 Clone from scratch: MK-U47
Post by: Brotastic on January 13, 2014, 05:19:31 AM
is there a release date?
Title: Re: U47 Clone from scratch: MK-U47
Post by: Category 5 on January 22, 2014, 10:21:49 AM
Please update us on the progress.  And please tell us it'll be soon!
Title: Re: U47 Clone from scratch: MK-U47
Post by: Brotastic on February 17, 2014, 07:19:14 PM
are you taking any pre-orders for these?
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on February 21, 2014, 02:33:29 PM
It's really about time for an update, thanks for the patience everyone.

I made a decision to be able to release the first batch of kits soon - they will be equipped with headgrilles made by FLEA.
FLEA is known for producing mic bodies for the finest U47 clones out there and i'm glad to include their handmade grille for this project.
There are still a few things to be done, but i'm looking at a timeframe of four to six weeks from now;
This was a long road but it feels good to see the light at the end of the tunnel.

I will soon post more details of whats included, options and pricing in a seperate feeler thread soon.
As usual i don't take any pre-payments for my products.

Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on February 21, 2014, 03:15:44 PM
I would hit like more than once if I could  ;)
Title: Re: U47 Clone from scratch: MK-U47
Post by: djn111 on February 22, 2014, 07:24:20 AM
Hm

six weeks, excellent timing, in that month I receive some extra payment for the summer holidays :-)\

DJN
Title: Re: U47 Clone from scratch: MK-U47
Post by: sr1200 on February 24, 2014, 12:13:04 AM
Are you doing polarity switch on the body or PS or not at all?
Title: Re: U47 Clone from scratch: MK-U47
Post by: fishdrop on February 25, 2014, 04:24:43 PM
any price info, yet??
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on February 26, 2014, 09:28:37 PM
Hey,

no final pricing as of yet.

Are you doing polarity switch on the body or PS or not at all?

Thats one thing i'm working on, changing the highZ board to include the relais for the (remote) pattern switching.

(http://www.twin-x.com/groupdiy/albums/userpics/New_HighZ_board.jpg)
Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on February 27, 2014, 06:47:49 AM
Hey Max,

now I'm a little confused because you wrote "remote" pattern switch - so it won't be on the body?
Maybe I got it wrong...

Why the relays? Why not do it as per the original?
Thanks



Hey,

no final pricing as of yet.

Are you doing polarity switch on the body or PS or not at all?

Thats one thing i'm working on, changing the highZ board to include the relais for the (remote) pattern switching.

(http://www.twin-x.com/groupdiy/albums/userpics/New_HighZ_board.jpg)
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on February 27, 2014, 04:06:53 PM
Hey Max,

now I'm a little confused because you wrote "remote" pattern switch - so it won't be on the body?
Maybe I got it wrong...

Why the relays? Why not do it as per the original?
Thanks

Hi Rainton,

the relais (one) is required for the pattern switch since the headbaskets i ordered from Flea do not have the switch cutout.
The switch will be in the Psu, just like the Mk47.
Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on February 27, 2014, 04:42:32 PM
Thanks Max,

I was really hoping for a pattern switch on the mic like the original...
...wasn't it what you wanted to do in the first place? At least as far as I remember the first pages of this thread.

Is there an option to use a head basket with pattern switch with the MK U47?
Like with the one from Oliver Archut (AMI) for example - or the one with pattern switch from Flea?

Thanks again!


Hey Max,

now I'm a little confused because you wrote "remote" pattern switch - so it won't be on the body?
Maybe I got it wrong...

Why the relays? Why not do it as per the original?
Thanks

Hi Rainton,

the relais (one) is required for the pattern switch since the headbaskets i ordered from Flea do not have the switch cutout.
The switch will be in the Psu, just like the Mk47.
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on February 27, 2014, 06:43:49 PM
Well the headbasket with pattern switch from Flea is 594 Euro - an amount i couldnt add to this kit.
Title: Re: U47 Clone from scratch: MK-U47
Post by: Phrazemaster on February 27, 2014, 07:24:19 PM
I have a complete FleA body kit for a U47 and man, they ain't cheap!!! But Ivan is cool at FleA, and their stuff is high quality.

I guess DIY'ing a headbasket clone would be pretty tough then, right Max? Just curious why you opted to get their headbasket to begin with. I thought you were going to have a mercury reed switch for the pattern...
Title: Re: U47 Clone from scratch: MK-U47
Post by: Category 5 on February 27, 2014, 07:34:23 PM
Well the headbasket with pattern switch from Flea is 594 Euro - an amount i couldnt add to this kit.

Good lookin out!  From what I've seen so far this kit is mandatory for me (already have a Thiersch and 20 tubes waiting) so glad to see it's not 100% accurate at unreasonable cost.  It'd be nice, but considering the pattern in the PSU route will be just fine and I doubt there will be audible difference.
Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on February 27, 2014, 07:45:36 PM
Well the headbasket with pattern switch from Flea is 594 Euro - an amount i couldnt add to this kit.

Yes you're right, it's really expensive - 594 Euros is for the complete head though - incl. everything but the capsule.
But even just their head grille with hole for the pattern switch comes in at 396 Euros!

That's why I mentioned TAB Funkenwerks U47 head grille which is 150$...

Max can you please give us the option to buy your MK-U47 kit without the head grille - for those who want to go the extra mile and
do it as per the original?

Even though I see the bottom plate of the head as well as the head plate of the body need to have a recess to place the pattern selection slider in there 

EDIT Shoot, just realized the body tube would have to have this notch, too  :-\

Title: Re: U47 Clone from scratch: MK-U47
Post by: Pip on March 08, 2014, 10:19:14 PM
So just a reminder its tax return season here in the USA so lets get cracking. Money must be spent on quality kit.
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on March 11, 2014, 06:57:38 PM
I have some really good news: After some back and forth FLEA agreed to machine the cutout for the pattern switch.
So, additionally to the flea quality, the mic will now have the cardioid/omni switch directly on the body - just as planned!
This might take a little longer than anticipated, but i'm very glad to be able to include this feature.
Title: Re: U47 Clone from scratch: MK-U47
Post by: rainton on March 11, 2014, 07:02:14 PM
I have some really good news: After some back and forth FLEA agreed to machine the cutout for the pattern switch.
So, additionally to the flea quality, the mic will now have the cardioid/omni switch directly on the body - just as planned!
This might take a little longer than anticipated, but i'm very glad to be able to include this feature.

Hooorayy!!  :)

This is awesome news Max! Thanks!
Title: Re: U47 Clone from scratch: MK-U47
Post by: fishdrop on March 12, 2014, 03:58:06 AM
I have some really good news: After some back and forth FLEA agreed to machine the cutout for the pattern switch.
So, additionally to the flea quality, the mic will now have the cardioid/omni switch directly on the body - just as planned!
This might take a little longer than anticipated, but i'm very glad to be able to include this feature.

Wooow. incredible   ;D  ;D  ;D
Title: Re: U47 Clone from scratch: MK-U47
Post by: sr1200 on March 12, 2014, 03:28:02 PM
Glad you posted, was just about to order the AMI kit.
Title: Re: U47 Clone from scratch: MK-U47
Post by: djn111 on March 12, 2014, 04:44:39 PM
I love it when a plan comes together  :D
Title: Re: U47 Clone from scratch: MK-U47
Post by: Brotastic on March 12, 2014, 06:02:08 PM
how much is the switch going to add to the cost and would there be on opt for a body without the switch.  If it saves me a couple of hundred dollars then I would rather not have the switch at the body.  It doesn't take much to switch the polar pattern at the PSU. 
Title: Re: U47 Clone from scratch: MK-U47
Post by: Category 5 on March 12, 2014, 08:36:01 PM
how much is the switch going to add to the cost and would there be on opt for a body without the switch.  If it saves me a couple of hundred dollars then I would rather not have the switch at the body.  It doesn't take much to switch the polar pattern at the PSU.

Well there's always the MK47 currently available if you're not going for authenticity.  I think if it can be done at similar cost to the original estimates lets go for it.  This version was supposed to be the physical clone, not just the electrical clone.

Title: Re: U47 Clone from scratch: MK-U47
Post by: Brotastic on March 13, 2014, 01:51:14 PM
Category 5, I am not trying to stir the pot and I know that a lot of individuals want the mic to be as authentic looking as possible.  I want to get this particular kit because I am looking for great sound and build quality.  I think Max is doing this with this project.  I don't remember him stating his goal was to have a physically authentic looking mic.  From what I gather he wants the best sound and build quality.  There are a lot of posts on this project and if I missed something...I do apologize in advance.  Everyone on the forum has different things that are important to them.  There is a lot of passion about these mice and for good reason.  So....

What is important to me, is sound first of all and build quality.  In my opinion, I could careless if the switch is on the body or the PSU.  So, if there is an option for that I would love to save a few hundred dollars.  If the cost is minimal, I would gladly have a mic with the polar pattern switch on the mic itself. 

What ever Max decides for the build will be fine with me.  I am going to get two mics regardless. 

I hope this clears things up. 
Title: Re: U47 Clone from scratch: MK-U47
Post by: Category 5 on March 13, 2014, 01:55:51 PM
No doubt.  Max had stated he was going with the FLEA to keep cost down. Now that they are going to cut the switch port I doubt that goal has changed.  We all win!
Title: Re: U47 Clone from scratch: MK-U47
Post by: Brotastic on March 13, 2014, 06:47:38 PM
I can't wait of the project to be available.  I agree, everyone will win with this mic. 
Title: Re: U47 Clone from scratch: MK-U47
Post by: digiteck on April 03, 2014, 03:03:57 AM
Hi Max,

i'm about to order a Thiersch Blue Line capsule, and i'm really interested by your kit and wonder if i need to buy the capsule holder from Thiersh or not ? And is there some differences between capsule holder ?

And can you let us know what will be included in your kit ?

Thanks for your help and keep up the good work !

Lionel
Title: Re: U47 Clone from scratch: MK-U47
Post by: ioaudio on April 04, 2014, 09:57:43 AM
For prototyping i am working with Flea's capsule holder, but Thiersch's holder will fit too.
The capsule holder will not be included. A summary of what's included will be presented soon.

-max
Title: Re: U47 Clone from scratch: MK-U47
Post by: digiteck on April 10, 2014, 05:44:23 PM
For prototyping i am working with Flea's capsule holder, but Thiersch's holder will fit too.
The capsule holder will not be included. A summary of what's included will be presented soon.

-max

Thanks for the feedback Max !

Title: Re: U47 Clone from scratch: MK-U47
Post by: RadHill on April 19, 2014, 05:59:30 PM
Excellent!

Please count me in for one or two.

Thank you.
Title: Re: MK-U47
Post by: Citrus Hill on May 01, 2014, 02:30:29 AM
i'm seriously hoping to be able to order a pair if i can swing the cost.  I've only heard great things about your trafos and kits, and i'm sure these mics will be as great.  Thanks for putting in all the hours on this!
Title: Re: MK-U47
Post by: vineyardgray on May 01, 2014, 01:21:44 PM
This is an exciting project.  I keep checking back to make sure I don't miss the limited release!  Knowing my luck, Max will release this and I'll be busy and the whole mess will sell out in minutes like McCartney tickets.  :o
Title: Re: MK-U47
Post by: iambeatmenace on May 01, 2014, 05:57:10 PM
Hi. I am interested in one of this mic kits. How much does it cost?. I'm interested in one kit.
Title: Re: MK-U47
Post by: Brotastic on May 01, 2014, 10:49:35 PM
I know.....I check everyday.
Title: Re: MK-U47
Post by: MicGeek on May 02, 2014, 12:00:15 PM
I'm interested in 2 of them  8)
Title: Re: MK-U47
Post by: liquidify on May 06, 2014, 03:57:53 AM
News on this?
Title: Re: MK-U47
Post by: tonycamp on May 06, 2014, 08:38:27 PM
some samples of a MK47/ matachung C12 in action over here
http://realgearonline.com/post/23074/thread
Title: Re: MK-U47
Post by: micaddict on May 07, 2014, 03:50:25 AM
Sounds great, Tony!



Henk
Title: Re: MK-U47
Post by: Brotastic on May 16, 2014, 05:06:52 PM
So......when is this project going to be available?   I just ordered two Blue Line Thiersch capsules and have the parts for the PSUsss.  Now I need bodies and guts!!   Ewww, that sounded gross.
Title: Re: MK-U47
Post by: liquidify on May 18, 2014, 04:01:42 AM
So......when is this project going to be available?   I just ordered two Blue Line Thiersch capsules and have the parts for the PSUsss.  Now I need bodies and guts!!   Ewww, that sounded gross.

Sounds like a full meal to me.  Ready to eat one myself.
Title: Re: MK-U47
Post by: ioaudio on May 19, 2014, 05:37:01 AM
Really about time for the main dish - everything is ready but i'm waiting for the headbaskets to arrive.
Title: Re: MK-U47
Post by: djn111 on May 19, 2014, 10:38:55 AM
How about a little starter, teaser picture :-)

DJN
Title: Re: MK-U47
Post by: Category 5 on May 19, 2014, 11:14:19 AM
Really about time for the main dish - everything is ready but i'm waiting for the headbaskets to arrive.

How much $$$ should I embezzle from the savings acct?  lol
Title: Re: MK-U47
Post by: Brotastic on May 19, 2014, 01:24:41 PM
Any details on pricing and availability? 

I needs my preciousessssessseseesssss!
Title: Re: MK-U47
Post by: kcatthedog on May 19, 2014, 09:44:07 PM
please help me to understand these arcane electrical Diy terms : "savings account", is a depository for electrical charges: I don't have one ?:)
Title: Re: MK-U47
Post by: liquidify on May 20, 2014, 01:41:09 PM
please help me to understand these arcane electrical Diy terms : "savings account", is a depository for electrical charges: I don't have one ?:)

With bitcoin, savings truly can be electrical charges.  Wonder if old IO would take bitcoins.
Title: Re: MK-U47
Post by: Pip on May 23, 2014, 09:25:11 PM
The suspense is killing me!
Title: Re: MK-U47
Post by: ioaudio on June 11, 2014, 06:31:14 PM
FLEA send the first batch of the headbaskets, and they look amazing.
So 25 Kits will be available soon.
Everything will be included except capsule and capsule holder, psu and cable (mic-connector is included).
Here's a shot from the exterior, a updated look from the inside & build pics will follow soon.

(http://www.twin-x.com/groupdiy/albums/userpics/MK-U47.jpg)
Title: Re: MK-U47
Post by: sr1200 on June 11, 2014, 06:33:36 PM
Wow!!! If there was a list started i hope im on it!!! Awesome job!!!!
Title: Re: MK-U47
Post by: rainton on June 11, 2014, 06:43:42 PM
Wow!!
Looks awesome!!

Wow!!! If there was a list started i hope im on it!!! Awesome job!!!!

As stated earlier in this thread - I guess it was over a year ago - I hope I'm on that list, too!!!!  ;)
Title: Re: MK-U47
Post by: Category 5 on June 11, 2014, 06:44:50 PM
OMG!!!  That's beautiful!  Give us a ballpark on price?
Title: Re: MK-U47
Post by: marcus4audio on June 11, 2014, 08:38:52 PM
Hey Max, looking great :) Whats the body finish? Is that matt nickel or its anodized aluminum?
Title: Re: MK-U47
Post by: liquidify on June 12, 2014, 12:35:19 AM
Looks amazing.  Every bit as beautiful as the original. 

In the first pictures from this thread, it appeared a brass color.  Is this a brass body with a finish?
Title: Re: MK-U47
Post by: fishdrop on June 12, 2014, 02:19:09 AM
wow. i follow this thread for quite a while.
it looks fantastic. i hope i can grab one.

 ;D
Title: Re: MK-U47
Post by: ciscan.81 on June 12, 2014, 02:31:25 AM
Hi Max...

I've been following this thread with great interest for a long time...as I'm sure many have.

Great to see it coming to fruition.

When you say  "everything" included, did you also mean the tubes? If so, which particular ones?

Very exciting. Well done on a spectacular project.

-W
Title: Re: MK-U47
Post by: djn111 on June 12, 2014, 03:08:38 AM
Wauw, looking realy good

DJN
Title: Re: MK-U47
Post by: micaddict on June 12, 2014, 05:15:47 AM
Yup, those are the business.
And they have been improved, too.
A couple of years ago they were already of a high quality, but they had a bowler hat top. Flea corrected that by flattening the top and they did it in a very smooth way.
Also, the top cross bar was too round and thin. That has been corrected now, too.
This is a serious replica headbasket.



Henk
Title: Re: MK-U47
Post by: tonycamp on June 12, 2014, 11:22:40 AM
i've been checking up here for what seems like forever on this... Now that it's almost here, why do i get the feeling that somethings going to happen to drain my funds right when it arrives... whoomp whoomp  :-\

I assume i'm on the list.. right? anyone know where the list is lol
Title: Re: MK-U47
Post by: fishdrop on June 12, 2014, 11:33:23 AM
So 25 Kits will be available soon.

ooooh 25 Kits. it will be a big battle on them!!!   ::)

Max: do you plan to make more kits after the 25 kits runs??
how much do you make in total?
Title: Re: MK-U47
Post by: chefducuisine on June 12, 2014, 11:54:21 AM
Max, this looks terrific...
As writtten on the first pages - count me in.
Title: Re: MK-U47
Post by: frans on June 12, 2014, 12:00:43 PM
A) so either there will be more than 25 kits
B) or maybe there will be at least more than 25 of this output transformer ...after all, this seems to be the part in the kit that beats every other U47-ish mic that has been before, right?
Somewhere a few pages back I wrote I want one of these kits - let's see how ioaudio will distribute the 25 mics amongst the starved crowd. I still want one of these.
Title: Re: MK-U47
Post by: ioaudio on June 12, 2014, 04:16:35 PM
Thanks guys ... I'm happy you like it.

>>Give us a ballpark on price?
Very soon.

>>Whats the body finish? Is that matt nickel or its anodized aluminum?
The mic body is brass, bead-blasted and nickel-plated

>>When you say  "everything" included, did you also mean the tubes? If so, which particular ones?
Although tube selection is always critical and preferences differ, i will include a pair of 6028 tubes to get you started.
I might sell burned-in and tested tubes at a later point.

>>Max: do you plan to make more kits after the 25 kits runs??

Yes. After the initial 25 which will be for sale midlle of next week, 25 more will follow as soon as FLEA has the headbaskets ready.
We see how this goes and I'll hopefully manufacture more after that.
I'll plan to stock up on more Bv.08's too.
Title: Re: MK-U47
Post by: Category 5 on June 12, 2014, 05:41:26 PM
Off to sell a kidney...
Title: Re: MK-U47
Post by: kcatthedog on June 17, 2014, 06:41:09 PM
Congratulations Max; that is a fine looking  (and I bet fine sounding) piece of work.  I hope you are very proud and thank you for going to so much effort; greatly appreciated !!
Title: Re: MK-U47
Post by: bancho on June 18, 2014, 03:33:32 AM
Awesome work Max!  :D
Count me in for one...

Yes. After the initial 25 which will be for sale midlle of next week, 25 more will follow as soon as FLEA has the headbaskets ready.
We see how this goes and I'll hopefully manufacture more after that.
I'll plan to stock up on more Bv.08's too.

... and btw today is the middle of "next" week!
weeeeeeeeeeeeee  ;D
Title: Re: MK-U47
Post by: ioaudio on June 18, 2014, 04:26:07 AM
Thanks for the kind words!
Unfortunately, there will be another small delay before the MK-U47 will be available.
The good news is that FLEA already started the production on the second batch, so it looks like the whole 50 pcs will become available within 2 weeks.
This also gives me some time to prepare the build documentation.

Title: Re: MK-U47
Post by: SKJGProject on June 18, 2014, 05:46:27 AM
count me in for one!!!
Title: Re: MK-U47
Post by: iambeatmenace on June 18, 2014, 07:10:50 AM
Any Information about pricing?
Title: Re: MK-U47
Post by: orenradio on June 19, 2014, 01:00:44 PM
Count me in for one as well!
Title: Re: MK-U47
Post by: Pip on June 19, 2014, 04:48:17 PM
I would like one as well.

Pip
Title: Re: MK-U47
Post by: green-fuzz on June 19, 2014, 08:02:08 PM
I'd like one as well...
Any information about pricing, though ? I know the question has been asked again and again, but even a very very wide range could help me knowing what kind of fight i'm getting into with my banker.

Denis


EDIT : Banker told me "no", so i'm going to cancel... for now.
Title: Re: MK-U47
Post by: djn111 on June 20, 2014, 01:50:42 AM
Hi,

I think a ruff calculation, you can make your self, MK47 kit 229,00 euro, head basket flea 400,00 euro, all the rest,metal work etc. shot in the dark 500,00 euro, so something between 1000 en 1250 euro is a ball park figure. Excluding tax for EU.

DJN
Title: Re: MK-U47
Post by: fishdrop on June 20, 2014, 05:13:08 AM
.... something between 1000 en 1250 euro is a ball park figure.....

i think thats very realistic. i came to a similar result when i did my math.

and by the way. I'm in for one, too
Title: Re: MK-U47
Post by: ioaudio on June 21, 2014, 08:57:38 PM
Kit and build description added to the first post.
Title: Re: MK-U47
Post by: tonycamp on June 21, 2014, 10:11:03 PM
Holy cow! :o that is a thing of beauty Max!!!
Title: Re: MK-U47
Post by: Jim50hertz on June 22, 2014, 01:12:36 AM
Looks like a super fun build! Nice work  8)
Title: Re: MK-U47
Post by: Pip on June 22, 2014, 02:14:38 AM
Finally we have lift off. Looks great! Hit me with the cost. I want it.
Title: Re: MK-U47
Post by: Brotastic on June 22, 2014, 03:08:05 AM
holy crappers!!!  When and how much!!!!
Title: Re: MK-U47
Post by: kcatthedog on June 22, 2014, 07:13:27 AM
Max,

as bad luck would have it my car is dieing so now is probably not a good time to be listening to your mk47 siren song, beautiful as her melody is :)

will there be another run after the first 50 ?

thx !
Title: Re: MK-U47
Post by: Marc Duchesne on June 22, 2014, 10:01:50 AM
In for 1, depending on price. This is an awesome looking mic.
Title: Re: MK-U47
Post by: reginator on June 22, 2014, 11:09:07 AM
Wowzers! Handcrafted just like a vintage Ferrari  8)
Title: Re: MK-U47
Post by: Johnkenn on June 22, 2014, 03:30:47 PM
How do you put in an order? I'd love to see a price first of course....
Title: Re: MK-U47
Post by: core13 on June 24, 2014, 04:34:07 PM
very interested waiting for price

I want to build it with an ef12 can you make an adaptation of the kit? for the tube holder?
thanks
Title: Re: MK-U47
Post by: vineyardgray on June 25, 2014, 12:05:42 PM
My my my. 

Mine mine mine!  :o

Gorgeous work.
 :)

Title: Re: MK-U47
Post by: bruno2000 on June 25, 2014, 12:57:34 PM
A little off topic, but I have had no less than 6 artists wanting to buy the MK-U47s I built.
Best,
Bruno2000
Title: Re: MK-U47
Post by: ioaudio on June 27, 2014, 05:36:56 PM
Hi all,

i'm resolving one last small issue with the pattern switch but i'll be finished any day now.
I'll add order details here and in my white market thread when i'm ready to go.
Title: Re: MK-U47
Post by: kcatthedog on June 28, 2014, 07:18:03 PM
hmm,, new 47 and a new car; why not ?
Title: Re: MK-U47
Post by: ioaudio on June 29, 2014, 12:01:08 PM
25 Kits available now: --> http://groupdiy.com/index.php?topic=35667.0
(http://www.twin-x.com/groupdiy/albums/userpics/MK-U47_24_kits.jpg)
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 05, 2014, 08:17:48 PM
Ok, since the first kits are about to arrive some guidelines:

Only work in a tidy, confined space, don't lose any screws or small parts.
Be gentle, never force in a screw if it doesn't turn easily.
To mount the headbasket, insert all 3 screws just a few turns to have some play to align the holes before tighting them.
Do not tighten these screws more than nescessary - just until they sit flush (this is also true for original u47)
I included a nylon m3 screw for the capsule mount - it can be easily shortened if needed.
The schematic/layout/wiring follows the original - except the wiring of the tubes.
Burn-in period of these tubes can be rather long - bake them for at least 48 hours before noise-judgement.
It is recommended to purchase extra tubes, for noise selection and to have spares for the future.

Time to thank all of you for your ongoing support, for your patience and for the kind and encouraging emails!
I hope you enjoy the build and record some wonderful music!

-Max
Title: Re: MK-U47 - first batch in!
Post by: tommypiper on July 06, 2014, 12:50:18 PM
Max, thanks.  Kit arrived. 

EDIT: continued via email.
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 06, 2014, 01:29:14 PM
Email send about the issue.
Title: Re: MK-U47 - first batch in!
Post by: Category 5 on July 09, 2014, 07:52:11 PM
Anyone receive and start theirs yet?  Dying to see some pics.
Title: Re: MK-U47 - first batch in!
Post by: Citrus Hill on July 09, 2014, 10:41:48 PM
Got mine in the mail on Monday.  I'm in the middle of a lot of work and I probably won't have much time until Sept., but i can't wait to get these started.  Still need to get the parts together for the psu units also. 
The kits look great, and i'm trying to decide on the right capsule for them.  I'm leaning towards a pair of Thiersch Blue Lines, but i'm not sure if i can swing that amount of coin yet.  I have a Beezneez K7 from the group buy that i might try out with it first.  can't wait! ;D
Title: Re: MK-U47 - first batch in!
Post by: frans on July 10, 2014, 02:29:40 AM
Mine are here and I'm thinking about what suspension or case..zayance's psu PCB looks good.. ... suggestions welcome.
Title: Re: MK-U47 - first batch in!
Post by: fishdrop on July 10, 2014, 06:53:22 AM
hey max,


which height do you recommend for the capsule holder?
i saw there are spacers included in the kit. so which capsule holder height makes for optimum flexibility??

in the build description you tell us to paint the resistor pcb black. why?? i don't get it  ;D


all the best
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 10, 2014, 09:52:05 AM
The Flea M7 holder i used has a overall height of 56 mm.

Resistor/Transformer painting is just for cosmetic reasons, of course you can leave it as is or paint any other colour.
No magic tricks involved here ;-)

-Max
Title: Re: MK-U47 - first batch in!
Post by: fishdrop on July 10, 2014, 11:40:36 AM
or paint any other colour.

yes. i thought about a nice pink colour  :D
just kidding.

i have the oppurtunity of joining a friend's order at Flea. I think you said that you use a Blue Line capsule by Thiersch together with the Flea capsule Holder. So Flea's Holder and Thiersch's Red Line capsule should be compatible, right??


all the best bernhard
Title: Re: MK-U47 - first batch in!
Post by: chefducuisine on July 10, 2014, 06:12:00 PM
Max,

can you please describe the connections on the tube connectors in more detail.
The pictures are difficult to interpret.
Something like a list of the connections in addition to the pictures.
e.g. Tube 1 pin 4 to pin 4 and 7 of tube 2 would be helpful.

Thank You.
Title: Re: MK-U47 - first batch in!
Post by: cowboycoalminer on July 10, 2014, 07:16:20 PM
Hi guys.  I'm missing the small reed contact from my kit.  Can someone tell me which it is so I can get one?

Thanks!
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 11, 2014, 07:56:54 AM
Chef - i just added a (quickly drawn) pic which shows the tube connections.

Cowboy,
the reed contact is in a small black container.

It appears that i forgot to add two srews and nuts for mounting the tube socket in each kit.
Those are not critical, any M2,5 or M3(#3 or#4) screws can be used.
If you want, i can send those screws in an envelope, just contact me via email.

thanks,
Max
Title: Re: MK-U47 - first batch in!
Post by: chefducuisine on July 11, 2014, 04:46:37 PM
Max,

thanks for the drawing - this was exactly what I was looking for.
Attached is a picture of my just completeted built.

...now let's built the power supply.

Regards,

Christian
Title: Re: MK-U47 - first batch in!
Post by: audiomsg on July 12, 2014, 10:28:50 PM
Hi Max
I was progressing very well with my build, but unfortunately I clumsily broke the reed switch...
I now need to get a replacement, could you let me know what the required specifications are so I can order a new one?
Thanks!
Olly
Title: Re: MK-U47 - first batch in!
Post by: bancho on July 13, 2014, 06:43:33 AM
How important is the 105V power supply? ... I mean is it necessarry to be exactly and stable 105V and how much the voltage variation influences the working of the mic?
Would the original schematics work? Could someone supply the schematics which is the best for using this mic?
I really don't need the pcb for this one as it is probaby simple enough to wire it p2p.
Thanks!
Title: Re: MK-U47 - first batch in!
Post by: bancho on July 13, 2014, 06:58:43 AM
oh, and another thing...
@Max: what about that tube adapter that was mentioned earlier - for eventual changing the dual tube for vf14 ?
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 13, 2014, 08:11:57 AM
I bought the reed contacts localy, but this one should fit: http://uk.farnell.com/coto-technology/ri-70gp0715/reed-switch-spst-7mm/dp/1081702


For the DIY version of this mic i left out the VF14 socket, since the single tubes are changed easier this way.

-Max

Title: Re: MK-U47 - first batch in!
Post by: stelin on July 15, 2014, 01:41:20 PM
Max: I got my kit today. Looks great! I have a question about the tubes you included: Are they tested, selected for low noise etc?

Thanks!
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 15, 2014, 06:27:24 PM
I included the tubes just to get you started, but they are from a batch which behaved quite good.
as noted, give them 48 hours to burn in before you judge their noise.
I'm also planning to sell burned-in and tested tubes at a later point., first have to set up the burn-in station.
Title: Re: MK-U47 - first batch in!
Post by: Le Roux on July 16, 2014, 09:29:29 PM
Man!!!  ;D

Max, just received mine.
Its fantastic!!!

This thing is so heavy duty!
Can't wait to start.

Thanks
Neil
Title: Re: MK-U47 - first batch in!
Post by: Category 5 on July 16, 2014, 10:57:33 PM
Comes up a lot, but anyone have a lead on where we can get some cool custom mic badges made up?
Title: Re: MK-U47 - first batch in!
Post by: kidvybes on July 17, 2014, 12:14:42 AM
Comes up a lot, but anyone have a lead on where we can get some cool custom mic badges made up?

...hey bro, not sure if the site is only temporarily down or not, but this was previously one of the sources for custom engraved mic badges:
http://prodigy-eng.com/services/laser-engraving/
Title: Re: MK-U47 - first batch in!
Post by: frans on July 17, 2014, 02:48:41 AM
For those in Europe, he's the man:
http://www.frontpanels.de/examples/
Title: Re: MK-U47 - first batch in!
Post by: stelin on July 19, 2014, 07:49:02 AM
Hi Max. The two resistors for the highZ board seems to have the same value (the same color coding). Is that correct? In the U-47 schematic I'm looking at, R1 is 100Mohm and R2 is 60Mohm.

Regards,
Stefan
Title: Re: MK-U47 - first batch in!
Post by: o3misha on July 19, 2014, 10:14:50 AM
Best resistors  for U47 are both 100M .  60M resistor was used  with 0.5uF coupling capacitor in U47. This 60M-0.5uF version was built for radio broadcasts , it has less low end than 100M-1uF version. Sometimes, 60M-0.5uF version even better: for vocal or other instruments ( natural low cut).  Grid resistor ( as a part of the highpass filter of the first order) and coupling capacitor (as part of a second-order highpass filter) affect on cutting of low frequencies. But, already a grid leak resistor 100 M you have 3 Hz filter cutoff. It is sufficient to apply the microphone in a studio.1G - too high value(!!!!) for most of old tubes. It is believed that higher grid resistor value may increase low end. But in reality,  you will not hear marked increase  low end  in comparison with 100M. Even smallest fluctuations temperature or humidity will cause fluctuations of 1G  resistors value, - it is not good. Of course, you can use laquer for avoiding of humidity influence. But that, huge  grid resistor may also  affect on stability of  work of the tube. Use normal value- 100M, believe me. I tried 220M  grid resistor with a few types of old German steell tubes (including VF14M), for example, and I did not hear any pleasant improvement in sound.
Title: Re: MK-U47 - first batch in!
Post by: stelin on July 19, 2014, 10:31:43 AM
Thank you, o3misha. Very helpful information!
/Stefan
Title: Re: MK-U47 - first batch in!
Post by: stelin on July 19, 2014, 04:40:04 PM
One more "stupid" question: What about the curled up green wire from the tube section to the highZ section? What does that do? Is there a specific length that is "enough"? Is it for increasing the resistans of the plastic cover of the wire?

/Stefan
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 19, 2014, 05:24:48 PM
I saw the curl or the coil in some of the vintage U47's. When i asked A.Grosser about it, he told me that Neumann service incorporated this very low-value coil of the grid wire for mics used nearby radio transmitters. I'm not sure if it has any effect, but i dig the looks ;-)

-Max
Title: Re: MK-U47 - first batch in!
Post by: kcatthedog on July 19, 2014, 09:36:25 PM
". I'm not sure if it has any effect, but i dig the looks ;-)"

Finally, the truth behind your mad (but Devine) reverse engineering endeavours !:)
Title: Re: MK-U47 - first batch in!
Post by: Melodeath00 on July 20, 2014, 10:47:46 AM
Best resistors  for U47 are both 100M .  60M resistor was used  with 0.5uF coupling capacitor in U47. This 60M-0.5uF version was built for radio broadcasts , it has less low end than 100M-1uF version. Sometimes, 60M-0.5uF version even better: for vocal or other instruments ( natural low cut).  Grid resistor ( as a part of the highpass filter of the first order) and coupling capacitor (as part of a second-order highpass filter) affect on cutting of low frequencies. But, already a grid leak resistor 100 M you have 3 Hz filter cutoff. It is sufficient to apply the microphone in a studio.1G - too high value(!!!!) for most of old tubes. It is believed that higher grid resistor value may increase low end. But in reality,  you will not hear marked increase  low end  in comparison with 100M. Even smallest fluctuations temperature or humidity will cause fluctuations of 1G  resistors value, - it is not good. Of course, you can use laquer for avoiding of humidity influence. But that, huge  grid resistor may also  affect on stability of  work of the tube. Use normal value- 100M, believe me. I tried 220M  grid resistor with a few types of old German steell tubes (including VF14M), for example, and I did not hear any pleasant improvement in sound.

I thought the change from 1uF to .5uF was due to transformer changes. I currently have 1G/1uF in my U47 clone, and I have been planning to swap to 60M/.5uF, but haven't gotten around to it yet.
Title: Re: MK-U47 - first batch in!
Post by: o3misha on July 20, 2014, 11:36:22 AM
There were no big differences between historical BV08 transformers concerning its parameters , inductance, impedance etc. So, there was no other  reason for decreasing of coupling cap from 1uF to 0.5uF,- only to reduce low end, which was undesirable for  usage of U47 in radio broadcasts. With  simple program- simulator  you can find that with 1uF you will get ~30Hz resonance  . When you use  grid resistor 100M  ( first-order high pass filter),  frequency response is linear with 1uF cap. If you reduce grid resistor value to 60M, than with 1uF cap you will find decrease of useful low frequencies from 100 Hz, already. it is not good.  That's why, if you use 60M you should also decrease coupling cap value to 0.5 uF.  0.5uF cap produces  resonance~40Hz. Linearity with 60M-0.5uF will be recovered.
So, with 100M-1uF and 60M-0.5uF you will have linear freq. response, but in first case you will have low end a bit deeper in very low frequencies.
Title: Re: MK-U47 - first batch in!
Post by: chefducuisine on July 21, 2014, 05:20:46 PM
Success!!!
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 21, 2014, 06:48:50 PM
Very nice Chef!
Important update: there was a error in the tube deck wiring schema regarding the yellow wire (thanks Chef!)
Title: Re: MK-U47 - first batch in!
Post by: Category 5 on July 21, 2014, 07:30:20 PM
Very nice Chef!
Important update: there was a error in the tube deck wiring schema regarding the yellow wire (thanks Chef!)

So schems are wrong but build blog is correct?  Where are the schems and support docs btw?
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 22, 2014, 10:17:27 AM
Yes, the pics are correct, i was refering to this "schema" which has been corrected now:

(http://www.twin-x.com/groupdiy/albums/userpics/Tube_wiring.jpg)

Title: Re: MK-U47 - first batch in!
Post by: bancho on July 22, 2014, 11:00:15 AM
Success!!!

Great!  :D
Where did you get the shockmount from?
Title: Re: MK-U47 - first batch in!
Post by: chefducuisine on July 22, 2014, 11:38:37 AM
The shock mount is from Flea.

If you want to go the modern route I recommend this one:
http://www.rycote.com/products/shock-mounts-suspension/invision-studio/invision-usm-vb/ (http://www.rycote.com/products/shock-mounts-suspension/invision-studio/invision-usm-vb/)

Regards,

Christian
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 23, 2014, 04:36:59 PM
I was just informed that the second batch of headbaskets was shipped from FLEA
so i'll be accepting orders soon - as usual in my WM thread: http://groupdiy.com/index.php?topic=35667.0
Title: Re: MK-U47 - first batch in!
Post by: fishdrop on July 24, 2014, 12:00:12 PM
Hey just finished my U47. I also started burning in the tubes.

So now i have a question.
i read that the voltage should be 105VDC. i built my PSU accordingly a calibrated it properly using a dummyload.
with the mic connected the voltage dropped to 95VDC. I readjusted my trimmer, but i cannot get more than 103,7VDC.

can i go go on burning in tubes??
or does it have to be 105VDC???
does the voltage change during burn in procedure??


all the best

bernhard
Title: Re: MK-U47 - first batch in!
Post by: chefducuisine on July 24, 2014, 03:31:43 PM
Bernhard,


Did you wire the heaters in series as ioaudio's drawing above?
If so please check that both tubes are slightly glowing.

Other than than that:
- Please specify your power supply. I assume you did something like the MK-47 Power supply. As this is a passive supply it is heavily dependent on the voltage present on the primary winding of the power tranny - for Europe it can be 230V +/-10%.
- Can you please specify your dummyload. How many Ohms???

You can simulate all this using this sofware:
http://www.duncanamps.com/psud2/ (http://www.duncanamps.com/psud2/)



Title: Re: MK-U47 - first batch in!
Post by: fishdrop on July 24, 2014, 04:19:02 PM
Did you wire the heaters in series as ioaudio's drawing above?

yes i did it exactly like that

- Please specify your power supply.

It's the MK47 PSU by Zayance.
during building the psu i measured the tranny. it gives me 210 vac.

- Can you please specify your dummyload. How many Ohms???

2,2k

at the moment i have 237VAC of the wall. the PSU voltage dropped to 102,2 VDC
Title: Re: MK-U47 - first batch in!
Post by: Matador on July 24, 2014, 04:36:24 PM
The output voltage will depend heavily on the actual tube quiescent current:  sounds like you just need to re-center the pot travel to give you some better adjustment room (right now you have it dialed to 0 and still aren't high enough on B+).

Did you use 330R or 680R for the third filter resistor?  I would start by soldering another resistor on it in parallel to drop it down some and give you an output voltage boost.
Title: Re: MK-U47 - first batch in!
Post by: chefducuisine on July 24, 2014, 04:45:45 PM
OK  -  this sounds good. (BTW: Having only 103,7V is a minor issue - the mic will work. ;))
Zayance's PCB is based on the schematic Max posted for the Mk-47.
What did you install on position R4 of the PS PCB?
If I interpret the schematic correctly you can put a 680 Ohms resistor here and - if needed - 330 Ohms resistor in parallel.

If the parallel resistor is installed this should result in an equivalent resistance of approx. 222 Ohms.
Together with the pot in maximum position this should result in approx. 700 Ohms.
Without the parallel resistor you'll get ca. 1300 Ohms.
This should give you enough room to get the output voltage right.
If it doesn't you can change the value of R4.
Please use the suggested simulation software - this will greatly help you understand what is going on and to what value you need to change R4 to move the trimming to the needed range.

Edit: Just saw Matador's post - sorry for parallel posting  :)
Title: Re: MK-U47 - first batch in!
Post by: fishdrop on July 24, 2014, 04:56:40 PM
Hey matador  & chefducuisine,


thanks for your help. R4 is aready 330 & 660 in parallel which makes 222 Ohm and my trimmer ist at 0 Ohm.
so i definitely will change the resistor after burning in the tubes. kinda strange. i mean with 237 VAC coming out of the wall????

just wanted to know if there is something to worry about or if this whole thing is a hint for something i should check.

the mic sounds good, and even better the longer it's turned on. no noise at all. it sounded awesome from scratch  ;D
i'm all excited about it.

Title: Re: MK-U47 - first batch in!
Post by: fishdrop on July 24, 2014, 05:05:13 PM
(http://www.twin-x.com/groupdiy/albums/userpics/Tube_wiring.jpg)

so is this the last, recent and correct tube wiring guide???

  ::) i think i wired it wrong
Title: Re: MK-U47 - first batch in!
Post by: Matador on July 24, 2014, 05:39:07 PM
Hey matador  & chefducuisine,


thanks for your help. R4 is aready 330 & 660 in parallel which makes 222 Ohm and my trimmer ist at 0 Ohm.
so i definitely will change the resistor after burning in the tubes. kinda strange. i mean with 237 VAC coming out of the wall????

just wanted to know if there is something to worry about or if this whole thing is a hint for something i should check.

the mic sounds good, and even better the longer it's turned on. no noise at all. it sounded awesome from scratch  ;D
i'm all excited about it.

To be honest, I wouldn't worry about it.  103V is close enough for jazz.

If you really wanted to sweat it, I would first lower both R1 and R2 down to 820 ohms to try and get the pot re-centered.  You want to try and hit 105V with the pot at 250ohms to give you adjustment range up and down.
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 24, 2014, 07:07:27 PM
(http://www.twin-x.com/groupdiy/albums/userpics/Tube_wiring.jpg)

so is this the last, recent and correct tube wiring guide???

  ::) i think i wired it wrong

Sorry for chiming in late - Yes there was an update on the yellow (heater) wiring!
Title: Re: MK-U47 - first batch in!
Post by: fishdrop on July 25, 2014, 03:25:59 AM
(http://www.twin-x.com/groupdiy/albums/userpics/Tube_wiring.jpg)

Sorry for chiming in late - Yes there was an update on the yellow (heater) wiring!

did i destroy anything?? or is everyhting alright, when i change this connection to the right pin?
whta's the effect of the misconnection?

the mic sounded good to me, but i never tried a original U47, so who knows
i swap the wire later and tell you whats going on.
Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 25, 2014, 08:48:42 AM
Nothing got hurt - only one tube was heated at a slightly higher voltage but it will be fine.

-Max
Title: Re: MK-U47 - first batch in!
Post by: fishdrop on July 25, 2014, 01:03:54 PM
i corrected the miswired cable.

now i can perfectly adjust the PSU Voltage to 105VDC. both tubes are glowing.

Title: Re: MK-U47 - first batch in!
Post by: ioaudio on July 25, 2014, 03:21:02 PM
Another 25 Kits available now --->http://groupdiy.com/index.php?topic=35667.0
Title: Re: MK-U47 - second batch in!
Post by: fishdrop on July 26, 2014, 09:48:37 AM
i already told some musicians about my new great mic.
right now i'm organising demo sessions, which i invite musicians and engineers to.

so they can try out the mic in a relxed atmosphere - i hope i will get some decent vocal/instrumental takes which i can put on my website for demo purpose.
and of course i will share this to the forum people as well.
Title: Re: MK-U47 - second batch in!
Post by: kcatthedog on July 26, 2014, 07:28:01 PM
Advice at soldering caps stage

I mistakenly cut the legs that protruded out of the pcp after soldering each cap from the inside. ( thought I was smart :))

As the ends of the cap and the  bottom resister legs were present on the outside of the pcp , I simply used a small piece of the leg to solder a bridge in place for each cap to its respective resister.

Will this be ok ?

thx!

Kcat
Title: Re: MK-U47 - second batch in!
Post by: ioaudio on July 27, 2014, 08:55:47 AM
Yes, no problem with that.

-Max
Title: Re: MK-U47 - second batch in!
Post by: stelin on July 30, 2014, 05:16:37 PM
Hi Max, do you have a schema for the MK-U47? I have seen original U47 schemas, and I know that you have followed the original very close (even the color of the wires are like the original), but the schemas I have found are of poor quality. They are also missing the parallell tube configuration, needless to say.
I want to have good documentation for the microphones I build. The MK-U47 will last for a long time and may very well end up i someone elses mic-collection some day.
Title: Re: MK-U47 - second batch in!
Post by: ioaudio on July 31, 2014, 12:57:28 PM
I will work on a clean Schematic for this build.
Title: Re: MK-U47 - second batch in!
Post by: rainton on July 31, 2014, 01:05:54 PM
Great!

I'm building mine right now, but I'm still confused with the tube wiring.
As far as I can see the photos of your wiring differ from the scheme that shows the wiring or am I mistaken?

In the scheme the heater wire goes from the 3rd pin (from right to left) of the one tube to the third pin of the other and the heater wire from the resistor is going to pin 4 of the first tube.

But in your build pics it seems the wire from the resistor is going to pin 3 of the first tube and pin 4 of the first tube is jumpered with pin 3 of the second tube...

I'm just asking because I just fired it up the first time and I measuring 114V at the power supply when the the pot is fully clockwise - so I can't get lower than that.
Disconnecting the mic and using the dummy load - I can dial in 105V perfectly fine...
Title: Re: MK-U47 - second batch in!
Post by: ioaudio on July 31, 2014, 01:18:36 PM
The pics can be a bit unclear, but if you wire following this schema everything's fine:


(http://www.twin-x.com/groupdiy/albums/userpics/Tube_wiring.jpg)
Title: Re: MK-U47 - second batch in!
Post by: rainton on July 31, 2014, 04:45:17 PM
Ok,
that's how I wired it Max :)

But when checking the voltage at my power supply I can't get below 110V with the mic connected.
I built the MK47 power supply with 230V toroid, a C-3X choke and three 1K ohm resistors in series with another 1K pot.
Using a dummie load of 2.2K I can dial in 105V pretty easily even though the pot is pretty far from being "centered" then.

Anyway should I try to raise the resistance in the power supply to get a voltage drop, or does the above mean something's wrong in my mic?
Not sure.
I haven't really tested it for sound yet since I switched it off after not being able to lower the voltage below 110V - didn't want to do any harm to the mic...



Also another question regarding the two 100 Mohm resistors in the Hi-Z part of the mic.

o3misha posted some great info on that, but he wrote that either you use 100Mohm with a 1uF coupling cap, or a 60Mohm with a 0.5uF coupling cap.
But the kit included two 100Mohm resistors for the Hi-Z and 0.5uF coupling cap?

I used the original schematic I have here (it's from 1959) and it says 60Mohm + 0.5uF coupling cap.
And since I the kit included a 0.5uF one and I had an 68Mohm resistor laying around I tried that.

Any more info on that matter?

Thanks!!
Title: Re: MK-U47 - second batch in!
Post by: ioaudio on July 31, 2014, 05:51:00 PM
The test load is used to bring the voltage to a ballbark figure - it ultimately should be dialed in with the microphone connected.
The (passive) U47 Psu is easy to adjust, just like Ohm's law - if you have to much voltage, add resistance.
Add a 220R in series and you'll be fine.

Re: HiZ resistors.
I found the 100meg works best. A.Grosser also told me that Neumann used 100meg in most of the u47's instead of 68meg although it was noted in the schematics.
Of course you can experiment, if you like the 68meg better (you can use two 33meg in series)

-Max
Title: Re: MK-U47 - second batch in!
Post by: Category 5 on August 06, 2014, 08:32:25 PM
Anyone interested in pre-made PSU's for this mic?  Beesneez mentioned a possible group rate for done PSUs.  the regular price was $300 U.S. so if a few more people are into it maybe we could get the cost down.

I want do to Chunger's BadAss PSU as soon as it's available, but that might not be sooner than later so I'm looking into this option for right now.
Title: Re: MK-U47 - second batch in!
Post by: ioaudio on August 07, 2014, 07:44:57 PM
Here's the Schematic:

(http://www.twin-x.com/groupdiy/albums/userpics/MK-U47_Schematic.GIF)
Title: Re: MK-U47 - second batch in!
Post by: Category 5 on August 08, 2014, 12:12:26 AM
Max, thabks so much for the schematic.  That will help.  It would also be helpful for you to do a diagram similar to the tube wiring diagram for the connector, resistor/tx board too since the pics are dark and difficult to see.  I have heard from at least two others that had some confusion doing this part and may have mis-wired as a result.

Also, what were the screws you recommend for the tube sockets?  Our hardware store didn't have anything shorter than 1/2"
Title: Re: MK-U47 - second batch in!
Post by: ioaudio on August 08, 2014, 08:44:48 AM
Here's the wiring plan:

(http://www.twin-x.com/groupdiy/albums/userpics/Mk-U47_Wiring.jpg)

Any screw smaller 1/8" will work, length is not a problem.
Title: Re: MK-U47 - second batch in!
Post by: kcatthedog on August 08, 2014, 08:38:22 PM
Anyone interested in pre-made PSU's for this mic?  Beesneez mentioned a possible group rate for done PSUs.  the regular price was $300 U.S. so if a few more people are into it maybe we could get the cost down.

I want do to Chunger's BadAss PSU as soon as it's available, but that might not be sooner than later so I'm looking into this option for right now.

I'm in !
Title: Re: MK-U47 - Official build thread
Post by: fishdrop on August 09, 2014, 12:10:28 PM
i did a Mic/Mic PreAmp comparison/shootout.
candidates were Max's MK-U47 and a friend's Lauten Tube Microphone which he likes best at the moment.
PreAmps: RME's Fireface, Black Lion Audio's Auteur, Bruno's SSL 4K & Golden Age 1073 Neve Clone

The Files are 24 bit, 44,1 khz recorded with my RME Multiface.

relax and enjoy:
https://dl.dropboxusercontent.com/u/841029/Lauten%20U47%20Vergleich%20mit%20tollen%20PreAmps.zip (https://dl.dropboxusercontent.com/u/841029/Lauten%20U47%20Vergleich%20mit%20tollen%20PreAmps.zip)
Title: Re: MK-U47 - Official build thread
Post by: kidvybes on August 09, 2014, 12:32:37 PM
i did a Mic/Mic PreAmp comparison/shootout.
candidates were Max's MK-U47 and a friend's Lauten Tube Microphone which he likes best at the moment.
PreAmps: RME's Fireface, Black Lion Audio's Auteur, Bruno's SSL 4K & Golden Age 1073 Neve Clone

The Files are 24 bit, 44,1 khz recorded with my RME Multiface.

relax and enjoy:
https://dl.dropboxusercontent.com/u/841029/Lauten%20U47%20Vergleich%20mit%20tollen%20PreAmps.zip (https://dl.dropboxusercontent.com/u/841029/Lauten%20U47%20Vergleich%20mit%20tollen%20PreAmps.zip)

Nice...do you know which Lauten tube mic that is? (Oceanus?)...both mics sound very good, but I suspect, depending on the density of the backing track, that the Lauten might sit better in a mix on that particular voice...it can be beneficial in these kind of comparisons to sample the vocals solo raw, and also vocals raw with backing track...often, what sounds best solo, doesn't always translate as such in the mix...

...what capsule is in your MK-U47?...
Title: Re: MK-U47 - Official build thread
Post by: fishdrop on August 09, 2014, 12:40:17 PM


Nice...do you know which Lauten tube mic that is? (Oceanus?)...both mics sound very good, but I suspect, depending on the density of the backing track, that the Lauten might sit better in a mix on your particular voice...it can be beneficial in these kind of comparisons to sample the vocals solo raw, and also vocals raw with backing track...often, what sounds best solo, doesn't always translate as such in the mix...

...what capsule is in your MK-U47?...

Hey i have the red line capsule by Siegfried Thiersch.
backing track to hear would be nice, but we were really focused an the mics and pres an really forgot to use a backing track. but i will do this as well the next time.  ;D

i'll ask my friend which lauten model that is.

i'm really amazed by the different sounds the pres suck out of the mics. especially with the u47 the sounds vary from pre to pre. very very nice. next time we'll try a tube pre as well

my friend was singing. everytime he stood in front of the U47 he had a bright smile in his face. he said that the headphone sound with a u47 is like dyamite and really creates a creative atmosphere.
Title: Re: MK-U47 - Official build thread
Post by: kidvybes on August 09, 2014, 12:51:33 PM

i'm really amazed by the different sounds the pres suck out of the mics. especially with the u47 the sounds vary from pre to pre. very very nice. next time we'll try a tube pre as well

my friend was singing. everytime he stood in front of the U47 he had a bright smile in his face. he said that the headphone sound with a u47 is like dyamite and really creates a creative atmosphere.

...true, but what I noticed is that the MK-U47 is so much bigger and warmer sounding, that it seems to pair nicely with the preamps that don't add to the size, thickness...IMHO, the cleaner preamps really bring out the best in the MK-U47, at least in this comparison...sounds wonderful!
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on August 09, 2014, 02:11:45 PM
MKU for me on pretty much all counts with that demo.  The Lauten has that sizzle that (if you like it) can bring a source forward in the mix, but it's hard to get rid of without botching the top end.  The MKU could easily stand as it does but would probably take a bit of high shelf well if you needed it to cut more.

Most people will mistake a boost in the highs for increased clarity, but it can often result in a source that's reluctant to sit down with the rest of the instruments in the track.

Im sure both mics could make a case for themselves in different situations, but here I like the 47.
Title: Re: MK-U47 - Official build thread
Post by: o3misha on August 10, 2014, 07:56:43 AM
i did a Mic/Mic PreAmp comparison/shootout.
candidates were Max's MK-U47 and a friend's Lauten Tube Microphone which he likes best at the moment.
PreAmps: RME's Fireface, Black Lion Audio's Auteur, Bruno's SSL 4K & Golden Age 1073 Neve Clone

The Files are 24 bit, 44,1 khz recorded with my RME Multiface.

relax and enjoy:
https://dl.dropboxusercontent.com/u/841029/Lauten%20U47%20Vergleich%20mit%20tollen%20PreAmps.zip (https://dl.dropboxusercontent.com/u/841029/Lauten%20U47%20Vergleich%20mit%20tollen%20PreAmps.zip)
Hey buddy, your u47 records are out of phase, judging on waveform.
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on August 10, 2014, 09:27:08 AM
i did a Mic/Mic PreAmp comparison/shootout.
candidates were Max's MK-U47 and a friend's Lauten Tube Microphone which he likes best at the moment.
PreAmps: RME's Fireface, Black Lion Audio's Auteur, Bruno's SSL 4K & Golden Age 1073 Neve Clone

The Files are 24 bit, 44,1 khz recorded with my RME Multiface.

relax and enjoy:
https://dl.dropboxusercontent.com/u/841029/Lauten%20U47%20Vergleich%20mit%20tollen%20PreAmps.zip (https://dl.dropboxusercontent.com/u/841029/Lauten%20U47%20Vergleich%20mit%20tollen%20PreAmps.zip)
Hey buddy, your u47 records are out of phase, judging on waveform.

Was just talking with a buddy who is a designer about this yesterday.  We were discussing how annoying it is that there is really no standard for polarity in mics, and especially old ones can be wired in reverse and cause grief.  This should definitely be corrected if the mic is to be used in any multi-mic situation. 
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on August 10, 2014, 08:37:06 PM
ah couldn't you just flip the polarity in your daw ?
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on August 10, 2014, 10:22:18 PM
ah couldn't you just flip the polarity in your daw ?

Well of course.  You could do it at the pre most of the time but it's a pain when you assume all of your mics have like polarity and find one is wired differently and causing phase issues. 
Title: Re: MK-U47 - Official build thread
Post by: o3misha on August 11, 2014, 03:24:41 AM
Moreover, in the antiphaze - a different feeling when singing.
Title: Re: MK-U47 - Official build thread
Post by: fishdrop on August 12, 2014, 04:54:02 AM
was on the road over the weekend and noticed that there were quite a few replies to my sound files.

does the original U47 have a phase flip, too?
or is it a problem with my specific one? i think i wired it according to original schematics.

changing the wires on output should not be a problem.
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on August 12, 2014, 07:03:59 AM
Hey fishdrop,

by the way what psu are you using ?

thax for clips !
Title: Re: MK-U47 - Official build thread
Post by: fishdrop on August 12, 2014, 07:28:10 AM
Hey fishdrop,

by the way what psu are you using ?

thax for clips !

Hey, no problem. Thursday i will make some more clips with two singers (a rock voice & a reggae singer) and some other PreAmps.

i used zyances MK47 PSU PCB which was designed for Max's former PCB based U47 Clone. i did not populate the parts for patternswitch, because i don't need this feature for this mic, of course.
Title: Re: MK-U47 - Official build thread
Post by: fishdrop on August 12, 2014, 07:30:38 AM
i did a Mic/Mic PreAmp comparison/shootout.
candidates were Max's MK-U47 and a friend's Lauten Tube Microphone which he likes best at the moment.
PreAmps: RME's Fireface, Black Lion Audio's Auteur, Bruno's SSL 4K & Golden Age 1073 Neve Clone

The Files are 24 bit, 44,1 khz recorded with my RME Multiface.

relax and enjoy:
https://dl.dropboxusercontent.com/u/841029/Lauten%20U47%20Vergleich%20mit%20tollen%20PreAmps.zip (https://dl.dropboxusercontent.com/u/841029/Lauten%20U47%20Vergleich%20mit%20tollen%20PreAmps.zip)

Nice...do you know which Lauten tube mic that is? (Oceanus?)...both mics sound very good, but I suspect, depending on the density of the backing track, that the Lauten might sit better in a mix on that particular voice...it can be beneficial in these kind of comparisons to sample the vocals solo raw, and also vocals raw with backing track...often, what sounds best solo, doesn't always translate as such in the mix...

...what capsule is in your MK-U47?...

It was a Lauten Oceanus by the way. i really liked it. totally different from the 47, of course. focussed on high mids, Presence and overtones.
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on August 13, 2014, 10:45:13 AM
Thank you for the comparison files!
If you're unsure regarding polarity, it's easily tested with headphones on (try humming and switch polarity on your preamp for maximum received bass)


Title: Re: MK-U47 - Official build thread
Post by: fishdrop on August 18, 2014, 07:26:01 AM
If you're unsure regarding polarity, it's easily tested with headphones on (try humming and switch polarity on your preamp for maximum received bass)

i did that exact same test with my MK-U47 and a friend's MK-U47.
checked waveforms and compared phase switch with headphones.

my mic is perfectly in phase. i don't know what made o3misha make that statement.

all the best
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on August 27, 2014, 09:57:14 AM
Currently 9 kits left, pls check my white market thread.
Title: Re: MK-U47 - Official build thread
Post by: stelin on August 28, 2014, 02:52:49 PM
Just a picture of my (MK) U47. Brass and stainless steel. Thiersch Red line capsule. Very nice!
You should know that Thiersch now make capsule mounts again. No need to by from Flea.
Title: Re: MK-U47 - Official build thread
Post by: Winetree on August 28, 2014, 02:56:18 PM
Wondering, What are the values of the two green P.I.O. caps?
Title: Re: MK-U47 - Official build thread
Post by: stelin on August 28, 2014, 03:09:21 PM
1uF 250V and 0,5uF 160V. See the schematic.
Title: Re: MK-U47 - Official build thread
Post by: audiomsg on September 01, 2014, 05:43:37 AM
Hi Max
I just wanted to say that I received the parcel with the capsule in it on Saturday, and immediately installed it in the MKU-47 body that I'd already finished.
Apart from a silly wiring mistake I made in the cable, it went without a hitch, and it sounds absoloutely beautiful.
I think I prefer the sound of the Thiersch Blue Line to the Cathedral Pipes M7 in my MK-47, but they are both great mics. (I would say that the CP "Dale" M7 is a touch darker)
You are probably well aware that the body construction of your MK-U47 kit is vastly superior to that of the Equinox Systems body, it's a beautiful piece of engineering, so thank you for making it available to people like me!
Kind regards
Olly Harmer
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on September 01, 2014, 08:59:47 AM
Max. Are more runs of this project planned? Would love to have a second but would rather fund it later than now.  ;)
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on September 01, 2014, 08:03:42 PM
Yes, I'm already working on the next batch.
Title: Re: MK-U47 - Official build thread
Post by: Energizer on September 04, 2014, 05:33:48 PM
Hi,
I finished the first MK-U47 (Thiersch red line / Zayance PCB based PSU) and the soldering iron is heating up for the second kit :)
I LOVE the sound, if you're interested to hear it I just made a video : http://www.youtube.com/watch?v=4FS7DAtWEx4 (http://www.youtube.com/watch?v=4FS7DAtWEx4)
The tracks are not dry but I hope it can give you an overview when it's used in a mix!
Peace,
Brice Sommen
Title: Re: MK-U47 - first batch in!
Post by: fazeka on September 04, 2014, 09:19:41 PM
I was progressing very well with my build, but unfortunately I clumsily broke the reed switch...

Hi Olly,

Unfortunately, me too!  :(  :(

Did you have to take everything apart again to put in the new reed switch? I'm hoping not...

Thanks,
Chris
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on September 05, 2014, 12:01:42 PM
Hi Chris,

this one works http://uk.farnell.com/coto-technology/ri-70gp0715/reed-switch-spst-7mm/dp/1081702

-Max
Title: Re: MK-U47 - Official build thread
Post by: fazeka on September 05, 2014, 05:13:01 PM
Hi Max,

Thanks, got it ordered from Newark in the U.S.

Now, just need to build the PSU...

Cheers,
Chris

Hi Chris,

this one works http://uk.farnell.com/coto-technology/ri-70gp0715/reed-switch-spst-7mm/dp/1081702

-Max
Title: Re: MK-U47 - Official build thread
Post by: stelin on September 08, 2014, 05:12:27 PM
This i my version of the PSU for the MK-U47. It worked the first time (except I had mounted the LED on the board the wrong way). I got 108V with the trim pot centered! Thats close. Now my MK-U47 is complete, and the testing has stared. I think I will have to put some labels on the PSU (for future generations). This mic will be around many years after I am not  :) . If anyone wants to see more pictures, I can post them.
Title: Re: MK-U47 - Official build thread
Post by: stelin on September 08, 2014, 05:19:34 PM
This is the other side of my PSU. As you can see I have a switch for the dummy load and a trimmer for the B+. Just needs some labels.  :)
Title: Re: MK-U47 - Official build thread
Post by: fazeka on September 08, 2014, 06:18:47 PM
Hi,

Nice! Do you have top, front and back views?

Thanks,
Chris
Title: Re: MK-U47 - Official build thread
Post by: stelin on September 09, 2014, 09:31:42 AM
Hi Chris,
This is the front. The PCB is mounted 60mm above the floor. I pushed everything over to one side to make room for the trimmer and the dummy load switch.
The trafo have two outputs: 200V and 6V. I used the 6V for an indicator lamp on the front.
Sorry, did not take any picture from directly above.
Title: Re: MK-U47 - Official build thread
Post by: stelin on September 09, 2014, 09:33:00 AM
And finally, this is a view of the back of the PSU.
Title: Re: MK-U47 - Official build thread
Post by: mgronroos on September 09, 2014, 06:41:19 PM
Cool, I like the "dual level" setup, Stelin, I might let my self be inspired by that idea..  8)

Solid work!

//Michael
Title: Re: MK-U47 - Official build thread
Post by: fazeka on September 09, 2014, 07:42:02 PM
Stelin,

Thanks! Nice pics/build.

I have a stupid question: where's the PSU PCB from?

Thanks,
Chris
Title: Re: MK-U47 - Official build thread
Post by: wolan42 on September 10, 2014, 03:05:13 AM
From Tony (zayance)
http://groupdiy.com/index.php?topic=53011.0


Beautiful Boards. ;-)
Title: Re: MK-U47 - Official build thread
Post by: stelin on September 10, 2014, 09:35:35 PM
I’m now in the process of testing and burning in tubes for my MK-U47. One problem is that there are two tubes in the mic. How do you select the tube with the lowest noise when you have to test them two at a time?
It would be nice to be able to run the mic with only one tube when measuring the noise. But, then the heater will not work, since the heaters are connected in series.
Does anyone have any thoughts or suggestions on that?

I have built two C-12 copies (MataChunger) to. The MK-U47 is about 5dB hotter than the C-12s, but even compensating for that, the MK-U47 is a lot noisier (at least 6db) so far. But then again, I was really surprised how quiet the C-12s with Mullard 12AT7 are.

Does anyone have any experience with the 6028/408a tubes? Do they vary much in noise levels? Do they need a long burn in time?

Thanks!
Stefan
Title: Re: MK-U47 - Official build thread
Post by: fazeka on September 11, 2014, 05:22:13 AM
Do they need a long burn in time?

48 hours according to Max.
Title: Re: MK-U47 - Official build thread
Post by: chunger on September 11, 2014, 05:31:34 AM
I’m now in the process of testing and burning in tubes for my MK-U47. One problem is that there are two tubes in the mic. How do you select the tube with the lowest noise when you have to test them two at a time?
It would be nice to be able to run the mic with only one tube when measuring the noise. But, then the heater will not work, since the heaters are connected in series.
Does anyone have any thoughts or suggestions on that?

I have built two C-12 copies (MataChunger) to. The MK-U47 is about 5dB hotter than the C-12s, but even compensating for that, the MK-U47 is a lot noisier (at least 6db) so far. But then again, I was really surprised how quiet the C-12s with Mullard 12AT7 are.

Does anyone have any experience with the 6028/408a tubes? Do they vary much in noise levels? Do they need a long burn in time?

Thanks!
Stefan

I have had very bad yield rate with Ebay 6028 and 408a tubes. . . I recommend buying many copies and then, after finding one pair that is confirmed quiet, I switch one tube at a time for testing subsequent tubes.  Finding the first pair can be a bit random though.
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on September 11, 2014, 10:28:13 AM
Yes, do not judge the noise behaviour before letting them bake for 48 hours.
The Jan tubes are kind of unique in this regard, but once the noise comes down they'll last very long.
Title: Re: MK-U47 - Official build thread
Post by: stelin on September 11, 2014, 01:50:26 PM
Thanks, ioaudio. I will make sure the tubes that came with the kit are burned in before a judge them.
/Stefan
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on September 11, 2014, 08:08:25 PM
I’m now in the process of testing and burning in tubes for my MK-U47. One problem is that there are two tubes in the mic. How do you select the tube with the lowest noise when you have to test them two at a time?
It would be nice to be able to run the mic with only one tube when measuring the noise. But, then the heater will not work, since the heaters are connected in series.
Does anyone have any thoughts or suggestions on that?

I have built two C-12 copies (MataChunger) to. The MK-U47 is about 5dB hotter than the C-12s, but even compensating for that, the MK-U47 is a lot noisier (at least 6db) so far. But then again, I was really surprised how quiet the C-12s with Mullard 12AT7 are.

Does anyone have any experience with the 6028/408a tubes? Do they vary much in noise levels? Do they need a long burn in time?

Thanks!
Stefan

cut to the chase and contact Christian at proaudiotubes, instead of wasting money on questionable tubes why not pay someone a a reasonable price for their professional service and get good tubes that are already burned in, tested and that he will stand behind ?
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on September 11, 2014, 09:35:15 PM
I’m now in the process of testing and burning in tubes for my MK-U47. One problem is that there are two tubes in the mic. How do you select the tube with the lowest noise when you have to test them two at a time?
It would be nice to be able to run the mic with only one tube when measuring the noise. But, then the heater will not work, since the heaters are connected in series.
Does anyone have any thoughts or suggestions on that?

I have built two C-12 copies (MataChunger) to. The MK-U47 is about 5dB hotter than the C-12s, but even compensating for that, the MK-U47 is a lot noisier (at least 6db) so far. But then again, I was really surprised how quiet the C-12s with Mullard 12AT7 are.

Does anyone have any experience with the 6028/408a tubes? Do they vary much in noise levels? Do they need a long burn in time?

Thanks!
Stefan

cut to the chase and contact Christian at proaudiotubes, instead of wasting money on questionable tubes why not pay someone a a reasonable price for their professional service and get good tubes that are already burned in, tested and that he will stand behind ?

Well, the JAN tubes will likely be fine after the recommended burn in, but for folks who want instant gratification I'll admit Christian is great and it's hard to go wrong with tubes from him.
Title: Re: MK-U47 - Official build thread
Post by: chunger on September 11, 2014, 10:22:30 PM
I’m now in the process of testing and burning in tubes for my MK-U47. One problem is that there are two tubes in the mic. How do you select the tube with the lowest noise when you have to test them two at a time?
It would be nice to be able to run the mic with only one tube when measuring the noise. But, then the heater will not work, since the heaters are connected in series.
Does anyone have any thoughts or suggestions on that?

I have built two C-12 copies (MataChunger) to. The MK-U47 is about 5dB hotter than the C-12s, but even compensating for that, the MK-U47 is a lot noisier (at least 6db) so far. But then again, I was really surprised how quiet the C-12s with Mullard 12AT7 are.

Does anyone have any experience with the 6028/408a tubes? Do they vary much in noise levels? Do they need a long burn in time?

Thanks!
Stefan

cut to the chase and contact Christian at proaudiotubes, instead of wasting money on questionable tubes why not pay someone a a reasonable price for their professional service and get good tubes that are already burned in, tested and that he will stand behind ?

Well, the JAN tubes will likely be fine after the recommended burn in, but for folks who want instant gratification I'll admit Christian is great and it's hard to go wrong with tubes from him.

I could be very wrong, but last i checked, Christian does not have a burn-in and test rig for the mk47 tubes.  Otherwise, i would have saved the hassle and purchased a pre-screened tube.
Title: Re: MK-U47 - Official build thread
Post by: stelin on September 12, 2014, 03:01:29 PM
That's right,  Chunger. Christian does not have a burn-in and test rig for the mk47 tubes (408a's).  He is selling WE 408a-tubes, but you have to test them and do the burn in youself. I know, because I have two that I bought from him.

When I first put the WE 408's in the mic, they had a bit to much noise. Now, they have been in the mic for 48 hours, and the noise has gone down a lot! The MK-U47 is now almost as quiet as my C-12's, and the noise is also a bit darker, which is a good thing.
Title: Re: MK-U47 - Official build thread
Post by: stelin on September 12, 2014, 03:54:40 PM
Shock mount on a shoe string budget... with a shoe string.

I've been waiting for a shock mount from the Land Down Under for some time. Needed a temporary solution.
This is it: A piece of leather from an old guitar strap, four cable ties and a shoe string. The outer ring is from a Blue mic I don't use very often. Not to bad, or what do you think?  :)
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on September 13, 2014, 02:14:36 PM
Shock mount on a shoe string budget... with a shoe string.

I've been waiting for a shock mount from the Land Down Under for some time. Needed a temporary solution.
This is it: A piece of leather from an old guitar strap, four cable ties and a shoe string. The outer ring is from a Blue mic I don't use very often. Not to bad, or what do you think?  :)

very good, but chunger at studio 939 has a well priced unit too !
Title: Re: MK-U47 - Official build thread
Post by: fazeka on September 14, 2014, 05:18:50 PM
Hi,

As I wait for Matador's/chunger's new PSU PCB and dan's case, I have started building a U87 clone.

But, I read that for that mic, cleaning all flux off is pretty critical due to impedance issues...

However, I didn't do that with my MK-U47 and it is already all assembled (which in and of itself was rather tedious for me).  :(

Do I have to deflux all my solder connections on the MK-U47? (I didn't see that in the instructions, possibly I missed it?).
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on September 14, 2014, 05:55:55 PM
Hi,

As I wait for Matador's/chunger's new PSU PCB and dan's case, I have started building a U87 clone.

But, I read that for that mic, cleaning all flux off is pretty critical due to impedance issues...

However, I didn't do that with my MK-U47 and it is already all assembled (which in and of itself was rather tedious for me).  :(

Do I have to deflux all my solder connections on the MK-U47? (I didn't see that in the instructions, possibly I missed it?).

Since the high impedance parts are floating it shouldn't be an issue.  Max told me this himself.
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on September 14, 2014, 06:24:21 PM
Yes,  all the critical HiZ parts are mounted on the acryl desk for this reason, no scrubbing nescessary.
Normal PCB material isn't up to the task - even after scrubbing - in use the pcb will absorb humidity and the resistance will decrease...sometimes only after a while...there is a reason why good mic designers use acryl and/or teflon standoffs for ALL HiZ connections.

-Max
Title: Re: MK-U47 - Official build thread
Post by: fazeka on September 14, 2014, 07:24:39 PM
OK, good to know! Thank you!
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on September 16, 2014, 10:02:34 AM
Currently the kits are sold out, working on a new batch.

-Max
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on September 22, 2014, 10:41:12 AM
11 Kits available now - those are the last kits with the tubes included and probably the last ones for 2014 - get them while they last!
--> http://www.groupdiy.com/index.php?topic=35667.0
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on September 28, 2014, 12:33:22 PM
Testing mike electronics

I set my PSU to 105 V and finished my Gotham cable, but the mike seems to not get power and/or to operate.

On power up Tubes do not glow, I switched in the originals and my 408a's nothing ?

I only have my one new cable with binder  and xlr 7 pin male connectors ,  suggestions for trouble shooting  would be appreciated.

Thanks.
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on September 28, 2014, 05:07:53 PM
You removed the test load from the psu right Kcat?

Check the wiring of your cable with a meter to make sure you didn't cross wires or get any shorts.  If that looks good it's time to retrace the mic wiring.  If nothing obvious just message me and we will figure it out.  If the tubes don't get hit the heater isn't working.  That's imperitive. 

I'm back in town tomorrow night and can be of better help. 
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on September 28, 2014, 09:11:52 PM
Hey Cat5,

Yes dummy load removed. I have power from pin5 from psu in the mike and have taken readings throughout out the mike confirming power in pin 5 and checking every junctier  to last 2 on cap.  I'll post in a bit.

Pretty certain me bad and I damaged the tube sockets strain testing them during build.

Everything has power and wiring to tube sockets. But no go bet I need to replace the sockets.

Drive safe!
Title: Trouble shooting mike electricals:tubes not powering up
Post by: kcatthedog on September 28, 2014, 10:42:55 PM

After setting rough voltage to 105 V, I disconnected the dummy load and plugged in the mike but I noticed the tubes do not glow or get warm.

I tracked the electricity from the psu 5 pin  from the inside of the 7 pin xlr without the cable attached it is 105v, with the cable attached it is 118V.

 so from the bottom of the mike up to the top here are the readings:

Pin 5 in base+ 118v so that confirmed that the cable I made is good

the orange wire leaving the resister is 118v

after the resister the yellow cable is 118V, yellow at the top of the mike socket is also 118V and the second socket also reads 118V

If I check the resister farm, its readings are

Starting at top

this is the end of the wire that sticks through on the far right hand side     Readings on the right and left hand side of the resisters

1   118v                                            118      117.9
2   106                                           118      105.8
3   118                                           117.9   105.7
4   118                                           117.5   117.7
5   118                                           117      117.6

At the top of the mike exiting form the yellow yoke my readings are:

Black   117.7
Blue   117.7
Yellow   117.7 1st, 118.3 2nd, 118.2 3rd position (following the wire)
Green   48 1st, 48, 2nd,48 3rd, 48.9 pin top of mike, 49 at mike
white   105.6 , 117.5 pin to mike, 117.5 last pin


Green to right of reed switch 48.9
Yellow left of reed switch          44.4, pin to mike 44.1

 I took readings by keeping my black probe to the ground at the switch in the psu and probed with the red following the circuit by wire colour code bottom to top.

The tubes never lit up nor got warm during this process.

So, there appears to be electricity everywhere it is supposed to but the tubes get now power?  I think I damaged the sockets and need to replace them.
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on September 28, 2014, 11:54:38 PM
You want that 118 to be 105 with the mic connected. 

From memory yellow is heater and should read about 20V. Red should be 105.  Blue is the output so you shouldn't see those volts there.  Double check the tube wiring and make sure it's the same as max's revised drawing.  Also double check the connections at the pcb and make sure there are no shorts and the connections are correct. 

I doubt you killed the tube sockets.  They are pretty simple and robust. 
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on September 29, 2014, 04:14:41 AM
Kcat,

sorry for the delayed reply. At this point i must warn you to be very careful with the voltages involved in such a tube project!
Please refrain from powering up the mic in this condiction. You will haver to check all connections again before the next power up attempt.
Do you have anyone nearby who could help you in person?
If not, you might consider sending the mic back top me for a checkup.

-Max
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on September 29, 2014, 08:02:09 AM
Hi Max,

Understood thx !

I'll check with Cat5 tonight and them email you to let you know status.
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on September 29, 2014, 10:38:38 AM
Perfect, i think it's better to have a second set of eyes on the mic now.
Thanks Cat5 for helping out!

Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on October 01, 2014, 12:49:56 AM
mk-u47 has landed !

Thanks to Cat5, Stefan and max, got everything dialed in tonight its working fine at 105.1v on the dial.  I put in the 408a and will let them cook for a couple of days.

I had mis-wired the b+ at the binder connector and yellow and green at tube sockets.

I redid my pcb like stefan and redid my gotham cable too

though my eyes were playing tricks on me when the tubes started glowing !

Can't wait to try it out; have the Thiersh blue cap !
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 01, 2014, 06:35:45 AM
Glad you did it - you got me a litlle worried there for a moment!
And a big thanks to Cat5!
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on October 01, 2014, 12:16:22 PM
Glad you did it - you got me a litlle worried there for a moment!
And a big thanks to Cat5!

All good Max!

I understood the danger and that I was doing build at my own responsibility.

I had only psu on power bar and never touched psu without ground probe in place and only holding plastic ends of probes.

Originally i wired up cable with an additional ground and had star ground in psu also !

Thanks again to you, zayance and Dan for making these great diy kits possible !
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on October 06, 2014, 03:49:04 PM
Wow do these things sound great.  I put a Blueline in Cowboy's mic and put the Redline in mine and have to say the choice is not as clear as I expected.  The Blue has a sweetness to the mids and top but the Red is bigger on bottom (like i expect from a 47) and possibly a touch more mid forward.  I can't pick a clear winner.

Also,  the Philips tubes were pretty quiet right off the bat.  Certainly quiet enough to use right away.  A pair of RCAs I tried next were even quieter from the start, and a little rounder down low.

Got some NOS WE 408a's however and MAN.  What's the deal with these suckers?  Static central from the start.  These things will really quiet down after burn in?  Do they really sound that much better than the Philips or RCAs?

Haven't installed the GE's I got yet, but so far the Philips and RCA are both winners from first power up.

Any other tube ideas out there?

EDIT - Wow.  I'm surprised to say that even after only a few hours running signal through the tube the noise has calmed down almost completely, and yes, the Western Electric tubes sound great.  Each brand of tube so far has it's own character and the WE seems to have the most build up on the transients (which is consequently a feature I love) and fantastic smoothness.  They are still not as wide on bottom as the RCAs, but definitely a contender for a permanent spot in the MK-U.
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 07, 2014, 05:48:09 AM
Thanks for the review on tubes! I used the Phillips most of the time, their noise level should come down even more after 48 hours of use.

-Max
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 09, 2014, 12:31:06 PM
Here's the schematic for the VF14 version:
(https://dl.dropboxusercontent.com/u/35386715/MK-U47-VF14_Schematic.GIF)
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 12, 2014, 10:59:39 AM
Also check out the thread on real-gear forums: http://realgearonline.com/thread/1585/mk-u47
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 17, 2014, 12:27:53 PM
Currently long time testing my "Mini-Passive" PSU - the original NG PSU in a small footprint:

(https://dl.dropboxusercontent.com/u/35386715/psu%20render.jpg)
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on October 17, 2014, 01:02:34 PM
Currently long time testing my "Mini-Passive" PSU - the original NG PSU in a small footprint:

(https://dl.dropboxusercontent.com/u/35386715/psu%20render.jpg)

Would like a couple of these!   That's a great looking little design Max! 

Will there be kits or just finished supplies?
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 17, 2014, 02:21:18 PM
I'm not 100% sure because of the housing etc.
Here's the mini version at prototyping stage, still waiting for the chassis mount resistors but voltages are good
and the noise level/hum is very low.
The circuit is the same as the original.
(https://dl.dropboxusercontent.com/u/35386715/psu%20prototyping.jpg)
Title: Re: MK-U47 - Official build thread
Post by: chefducuisine on October 17, 2014, 02:49:35 PM
Max,

I hope it's not too late:
I built my power supply with resistors in a TO-220 case.
The advantages:
- No wires - solderable to the PCB
- op to 20W Heat dissipation when mounted to a heat sink
- comperatively small size

I'll put up a picture tomorrow.

To get the idea look at this
http://www.reichelt.de/Dickschichtwiderstaende-TO220/RTO-20F-1-0K/3/index.html?&ACTION=3&LA=2&ARTICLE=89475&GROUPID=4336&artnr=RTO+20F+1%2C0K (http://www.reichelt.de/Dickschichtwiderstaende-TO220/RTO-20F-1-0K/3/index.html?&ACTION=3&LA=2&ARTICLE=89475&GROUPID=4336&artnr=RTO+20F+1%2C0K)
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 17, 2014, 02:55:07 PM
I know they exist, but i prefer the wire wound resistors over the thick films to keep it closer to the original.
Title: Re: MK-U47 - Official build thread
Post by: chefducuisine on October 20, 2014, 01:33:37 PM
twin-x doesn't work currently...
Title: Re: MK-U47 - Official build thread
Post by: chefducuisine on October 20, 2014, 01:34:59 PM
...number two
Title: Re: MK-U47 - Official build thread
Post by: chefducuisine on October 20, 2014, 01:39:59 PM
...number three.

The heatsink ist sandwiched together witch the breadboard containing the capacitors and the rectifier diodes.
The pictures should give you an idea.

@Max do you wind the power transformer yourself? If so would it be possible to wind one with  stepped HV tabs (110, 140, 160, 180, 200V) and a 12v Tab. This would be an excellent tranny for this and other tube mic projects.
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 21, 2014, 12:51:49 PM
No, i don't wind power transformers.
Nice, modern take on the PSU, Chef! Are you getting any noise from the thick films during warm up?
Title: Re: MK-U47 - Official build thread
Post by: chefducuisine on October 21, 2014, 12:57:31 PM
When switching on there is a short built up of noise for about 5-10 sec, after that it dissapers again.
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 23, 2014, 02:19:50 PM
Cool, i had some noise issues when i tried those resistors, but they where probably from a different brand.
Title: Re: MK-U47 - Official build thread
Post by: mateus on October 23, 2014, 03:29:03 PM
Heya there io!
Amazing job in this one, as usual.

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

Regards!
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on October 23, 2014, 07:34:27 PM
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!
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 25, 2014, 09:59:18 AM
Yes, bad timing unfortunately, but i'm already working on the next batch!

-Max
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on October 25, 2014, 02:55:37 PM
Yes, bad timing unfortunately, but i'm already working on the next batch!

-Max


Ho HO Ho !!!

luv Santa
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on October 27, 2014, 11:55:43 AM
I'm not sure if i will manage to finish the batch before early 2015, but I'll keep you updated.

Title: Re: MK-U47 - Official build thread
Post by: ioaudio on November 14, 2014, 05:57:57 PM
Looks like i will have a very small batch soon available, check my WM thread for updates.

-Max
Title: Re: MK-U47 - Official build thread
Post by: stelin on November 26, 2014, 06:40:04 PM
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
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on November 27, 2014, 07:45:05 AM
Very nice pic - thanks Stefan!
Title: Re: MK-U47 - Official build thread
Post by: Melodeath00 on November 27, 2014, 05:12:45 PM
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?
Title: Re: MK-U47 - Official build thread
Post by: djn111 on November 27, 2014, 05:19:46 PM
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.

(http://i46.photobucket.com/albums/f146/djn111/36x36mmlogo_zpsc37fee7e.png)

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

(http://i46.photobucket.com/albums/f146/djn111/powersupplylogo_zps7269d4c3.png)

DJN
Title: Re: MK-U47 - Official build thread
Post by: djn111 on November 27, 2014, 05:26:14 PM
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
Title: Re: MK-U47 - Official build thread
Post by: Category 5 on November 27, 2014, 05:32:21 PM
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.
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on November 27, 2014, 06:54:00 PM
if you buy a zayance pcb he gives you a bom for mouser

people are buying cases from dan at collectivecase
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on November 28, 2014, 07:45:57 AM
Yes Zayance's boards - recommended.
Title: Re: MK-U47 - Official build thread
Post by: Bri_guy on December 04, 2014, 02:15:49 PM
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
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on December 04, 2014, 04:40:45 PM
how long were they burned in ?
Title: Re: MK-U47 - Official build thread
Post by: Bri_guy on December 04, 2014, 05:02:19 PM
I didn't really burn them in for any extended time. Do you think that a burn in period would affect these issues?
Title: Re: MK-U47 - Official build thread
Post by: kcatthedog on December 04, 2014, 06:27:31 PM
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 ?
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on December 04, 2014, 07:12:59 PM
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
Title: Re: MK-U47 - Official build thread
Post by: Bri_guy on December 04, 2014, 10:52:21 PM
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.
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on December 05, 2014, 03:45:44 AM
Brian,

since you have a original U47 with VF14 you will notice that it heats up in the same way.
No need to change the transformer configuration for the EF14 or dual 6028/408a.
-20dB is a lot. Maybe an wiring issue at the output? Did you try another capsule?
Title: Re: MK-U47 - Official build thread
Post by: Bri_guy on December 05, 2014, 07:53:47 AM
I'll try switching out capsules...we've traced the wiring and can't seem to find a discrepancy. Has anyone had any issues with a new Thiersch  cap that you know of?
Thanks for the suggestions btw.
Title: Re: MK-U47 - Official build thread
Post by: frans on December 05, 2014, 08:40:04 AM
I read in the old ioaudio U47 thread, that somebody had trouble because he used the Thiersch capsule in a non-Thiersch capsule holder, which gave him a -10 dB level drop? It doesn't hurt to have a cheap capsule in the drawer just to test things/swap/check.
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on December 05, 2014, 01:06:11 PM
Brian,

no in fact Thiersch's capsules are amongst the best from a QC / Failure standpoint, it's just one thing to rule out.

Frans,

that was the MK47 project with the capsule holder from the chinese housing - in my MK-U47 housing the whole capsule assembly is perfectly isolated.
Title: Re: MK-U47 - Official build thread
Post by: barbaroja on December 06, 2014, 08:49:53 PM
If I have time tomorrow, I can record a comparison between the MK and my old 47.

I can never hear too much clips. Please do.
Title: Re: MK-U47 - Official build thread
Post by: micaddict on December 07, 2014, 05:52:13 AM
Quote
I can never hear too much clips. Please do.

+100
Title: Re: MK-U47 - Official build thread
Post by: Bri_guy on December 10, 2014, 01:33:33 PM
So, We've ruled out the capsule and the tube as possible issues. We still have low gain. Is it possible to get the pinout of the BV08?
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on December 10, 2014, 03:40:12 PM
The pinout can be found in my WM thread, scroll down to bv.08 http://groupdiy.com/index.php?topic=35667.0
Looking at the picture above the orientation is correct.
Re-check all connections, verify resistors are in the correct place etc.

-Max
Title: Re: MK-U47 - Official build thread
Post by: Bri_guy on December 21, 2014, 11:54:41 AM
We solved the problem. It seems that the Flea capsule holder wasn't completely isolated. I didn't originally fit the plastic washers...once we put a  couple washers at the base of the mount...we were in business. The mic sounds Fantastic! Louder and fuller than my Wunder CM7 (both have EF-14 tubes).  Less mid-forward than my vintage 47 (VF-14). I'm looking forward to the next batch so that I can complete a pair...thanks Max!
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on December 21, 2014, 12:22:43 PM
That's good to hear - yes the acrylic washers are crucial for the isolation!
Don't forget to give the dual 6028/408a circuit a try - you might like it!
Title: Re: MK-U47 - Official build thread
Post by: chefducuisine on December 21, 2014, 12:23:34 PM
Less mid-forward than my vintage 47 (VF-14).

Did you adjust the 27 Ohms resistor already?
Tune to taste to get closer to your vintage one.
Title: Re: MK-U47 - Official build thread
Post by: Bri_guy on December 21, 2014, 01:02:20 PM
Less mid-forward than my vintage 47 (VF-14).

Did you adjust the 27 Ohms resistor already?
Tune to taste to get closer to your vintage one.
We copied the Wunder and used a 2.2k resistor and bypassed it with 47mf cap...I may go back to a 29 Ohms resistor and remove the cap and compare.
Title: Re: MK-U47 - Official build thread
Post by: frans on December 23, 2014, 06:08:22 AM
Ah, so it had to do with the capsule holder, as I suspected in my earlier post. What i meant - and sorry if I worded it open to misunderstanding - was that the capsule and holder didn't work together 100%. Of course Thiersch capsules are great, no doubt about that. I won't diss the Flea capsule holder either, sometimes things just behave in tandem as we hope they do...or we overlook something. That's why groupdiy is so great - people who know that stuff contribute to help those who don't know that much. (like me)   :)
Title: Re: MK-U47 - Official build thread
Post by: Pip on December 30, 2014, 05:32:53 PM
So it is done and it sounds wonderful, more on that later. Thank You so much Max for all you do this is truly a beautiful project and it has been a joy to work on. It is truly one of the highest points in my DIY career and I am now what some consider middle aged!

Only a few notes that are build specific. I had to play with the resistor values in the PSU to get to the variable range to the 105VDC range (no big deal). I used Zayance's wonderful PCB for the build (also a thing of beauty) but pay strict attention to the ground plane on this board as it is not complete and you need to ground it properly. Lastly I broke the reed switch the first time trying to align it and had to buy another, again not of issue they cost under a dollar US so I bought 10.

I used the Thierch Blue Line M7. Wow! :-*

Sound is wonderful!!!!!! But I must share a subjective point I started with the kit supplied Phillips 408a tubes and they are very clean sounding and quiet. But they are also harsh on the high frequency with an emphasis that leads to annoying sibilance issues. So I switched out the Phillips to the venerable Western Electric 408a. Now these tubes are problematic as they are, to my ear noisier and often not NOS, but pulls from HiFi gear depending on where you get them so the are also prone to annoying artifacts like pops. so it took a few days of burn in and swap out before I got two that sounded really good but again to my ear slightly noisier than the Phillips. But oh what a sweet sound they have and the high end to my ear is bright but not harsh without sibilant annoyance. So that is my take on that IMHO as it is said.

Title: Re: MK-U47 - Official build thread
Post by: Pip on December 30, 2014, 05:36:09 PM
One more pic if you like!
Title: Re: MK-U47 - Official build thread
Post by: Melodeath00 on December 30, 2014, 09:49:46 PM
Less mid-forward than my vintage 47 (VF-14).

Did you adjust the 27 Ohms resistor already?
Tune to taste to get closer to your vintage one.

Care to explain? I understand the 29ohm resistor in the U47 affects the bias point of the tube. But would this change the frequency response/"forwardness"?
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on December 31, 2014, 11:38:05 AM
Thanks Pip! If you give the Jan 6028 tubes more time to burn in, you might prefer the sound.

I think there's some confusion regarding the 29 Ohm resistor, since "Bri_guy" uses the ef14 with another circuit.

Happy new year everyone!

-Max
Title: Re: MK-U47 - Official build thread
Post by: martthie_08 on January 13, 2015, 04:25:06 PM
just a quick question, I have started to build my mk-u47 and want to use it with the Flea capsule holder. This capsule holder has a orientation pin that gets in the way of the supplied capsule standoff, what is the preferred method of dealing with this? The way I see it one way would be to clip off the orientation pin, or drill a tiny hole into the standoffs... btw. how many layers of standoff discs are people using for the Flea capsule holder? I assume just one?

thank you so much for this great kit, very nice craftsmanship on all the parts!
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on January 13, 2015, 04:59:07 PM
You can just pullthe pin out - i use 1, but you might try 2 spacers for the flea holder.
Title: Re: MK-U47 - Official build thread
Post by: martthie_08 on January 13, 2015, 05:56:06 PM
ok, pulled it out, thanks for the info!

the supplied m3 plastic screw for the capsule holder is pretty long, I shortened it about 5mm...

EDIT: the Flea capsule holder is rather high, so I left out the spacers altogether.
Now the top of the capsule is roughly aligned with the upper metal bracing on the head basket.
Title: Re: MK-U47 - Official build thread
Post by: martthie_08 on January 14, 2015, 06:17:52 AM
ok, the mic build is completed for now, moving on to the psu:

I am using the collective cases psu with Binder connector, the recommended part number is # 09 0044 00 07 which is available from Conrad as catalog number 739030 (€20,99)

As this is a 7 pin connector it got me thinking if I would be possible to find an equivalent 6-pin Binder connector, like the supplied connector from Max, but it seems they are only available as 5 or 7 pin versions. Too bad, because the 6 pin versions are a lot cheaper...

anyways, the 7 pin cable plug is also available from Conrad as catalog number 739006 (€28,99). Not meaning to promote this company  ;) but maybe this info helps other builders...
Title: Re: MK-U47 - Official build thread
Post by: frans on January 15, 2015, 05:54:44 AM
Excuse my lack of knowledge, gdiy crowd - i understand about the buildup of lowend in cardioid, but why does my beloved MK-U47 even have more lowend if i slightly tap the mic body while in cardioid compared to omni?
Title: Re: MK-U47 - Official build thread
Post by: micaddict on January 15, 2015, 06:16:13 AM
Excuse my lack of knowledge, gdiy crowd - i understand about the buildup of lowend in cardioid, but why does my beloved MK-U47 even have more lowend if i slightly tap the mic body while in cardioid compared to omni?

Because the body is in close proximity of the capsule?
Title: Re: MK-U47 - Official build thread
Post by: frans on January 15, 2015, 06:35:48 AM
Wouldn't it then not be the same "ooooomph!" if i tap while in cardioid AND omni? But in omni it sounds leaner.
Title: Re: MK-U47 - Official build thread
Post by: micaddict on January 15, 2015, 07:59:59 AM
Wouldn't it then not be the same "ooooomph!" if i tap while in cardioid AND omni? But in omni it sounds leaner.

The bass build up in cardioid is caused by the proximity effect.  It doesn't matter if the sound source is a voice, a guitar or a microphone body used as a drum. As long as that source is close to the capsule (the mic's body very much is, obviously), there'll be a noticeable bass build up in cardioid.

Then there's the direct coupling (not the case with other sound sources). "Handling noise" is not the same thing as proximity effect, but I'd say they're connected. Omni's, especially true pressure mics, are known to have low handling noise.
On the other hand, true omni condensers go deeper into the subsonic range.

And then there are dynamic moving coil mics that have their own physical idiosyncrasies.

Title: Re: MK-U47 - Official build thread
Post by: stelin on January 30, 2015, 05:09:56 PM
Comparing my MK-U47 to an original U-47 and my Chunger/Matador C12 to an AKG C12 VR at Pama Records Studio 3 in Sweden.
The MK-U47 and the U47 sounded so similar that Pama want me to build a MK-U47 for them.
The Chunger/Matador C12 sounded so much better than the (familiar) AKG C12 VR that the studio owner was a bit stunned. Lots more openness and details in the middle range.
I’m not sure that he has ever heard a “real” C-12. To my ears, the AKG C12 VR sounded flat and a bit dull.
Sorry, no clips at this time.
Title: Re: MK-U47 - Official build thread
Post by: Tim Campbell on January 30, 2015, 09:08:06 PM
In the C12 what capsule and transformer?
In the 47 what tubes, transformer and capsule?
Title: Re: MK-U47 - Official build thread
Post by: stelin on January 31, 2015, 02:51:35 PM
Chunger/Matador C12: CT12 capsule, AMI transformer (from Chungers C-12 kit) and Mullard 12AT7 tube.

MK-U47: Thiersch Red Line capsule,  Max's Bv.08 transformer and two WE 408A tubes.

Title: Re: MK-U47 - Official build thread
Post by: Matador on January 31, 2015, 04:48:46 PM
The Chunger/Matador C12 sounded so much better than the (familiar) AKG C12 VR that the studio owner was a bit stunned. Lots more openness and details in the middle range.

Never underestimate the improved sonics one gets with a yellow PCB. :)
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on February 05, 2015, 06:04:38 PM
Hi Everyone,

just wanted to let you know that I'm working on the next batch, which should become available in approx 3 to 4 weeks.

-Max
Title: MK-U47 - first use and listen 1
Post by: kcatthedog on February 15, 2015, 05:14:23 AM
I finally have had the pleasure of using my mike, long story short I damaged my cap and had to send it back blah blah blah.

But i was recording with my mike yesterday with We 408a's, although they are still burning in and the cap is brand spanking new, I am so pleased with the presence and tone of the mike;its voice ! Everything I had hoped for and more. Great work Max !

Thx Max, Cat5 and TonyC: you all know why :)

my 47 starting off right burning in listening to the beatles on repeat !
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on February 18, 2015, 02:30:56 PM
Thanks Matt!
Title: Re: MK-U47 - Official build thread
Post by: kidvybes on March 01, 2015, 11:13:20 PM
For those who haven't followed the RGO boards, lots of activity over here for the MK-U47, including a tube choice worth looking into:

http://realgearonline.com/thread/2473/jks-mku47-build-thread

http://realgearonline.com/thread/2859/winecamp-mic-pre-shootout
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on March 03, 2015, 08:39:50 PM
Thanks for the link - been away from the net for a couple of days !

-Max
Title: Re: MK-U47 - Official build thread
Post by: stelin on March 09, 2015, 07:03:47 PM
Max,

The MK-U47 uses two tubes. I want to check the noise level of individual tubes. I have a bunch of 408a tubes and I want to find the least noisy ones.
Is there any practical way to test a single tube for noise in the MK-U47 circuitry?  I understand that the heaters are connected in series, so I would have to replace the second tube with a resistor to compensate for the missing heater, but beyond that I don't know what I can and can not do.
Any advice or thoughts about that?

- Stefan
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on March 10, 2015, 01:24:38 PM
Yes that's possible - just connect a 400 Ohm resistor (2watt or larger) to the heater pins of the second, unused tube socket.
-Max
Title: Re: MK-U47 - Official build thread
Post by: Inglev on March 21, 2015, 07:02:05 PM
My MK-U47 is complete. Did a comparison between the MK-U47 (which has a Thiersch Red Line), a Neumann U47 with a K47, and also my C12 clone (Tim Campbell capsule) and a Neumann M269 thrown in the mix for fun.

Here's a sample of each microphone:
Mic 1: https://www.dropbox.com/s/ca6uywhw7f355g6/Mic%201.wav?dl=0
Mic 2: https://www.dropbox.com/s/adytkn2rw3lvdm8/Mic%202.wav?dl=0
Mic 3: https://www.dropbox.com/s/hnp82zqm8db11tr/Mic%203.wav?dl=0
Mic 4: https://www.dropbox.com/s/6nja0uu3uugep1l/Mic%204.wav?dl=0

See if you can guess which is which  ;).
Title: Re: MK-U47 - Official build thread
Post by: HHH on March 21, 2015, 08:00:24 PM
My MK-U47 is complete. Did a comparison between the MK-U47 (which has a Thiersch Red Line), a Neumann U47 with a K47, and also my C12 clone (Tim Campbell capsule) and a Neumann M269 thrown in the mix for fun.
----
See if you can guess which is which  ;).

#1 = MK-U47
#2 = C12
#3 = Neumann U47
#4 = M269
Title: Re: MK-U47 - Official build thread
Post by: kidvybes on March 21, 2015, 09:22:54 PM
My MK-U47 is complete. Did a comparison between the MK-U47 (which has a Thiersch Red Line), a Neumann U47 with a K47, and also my C12 clone (Tim Campbell capsule) and a Neumann M269 thrown in the mix for fun.
See if you can guess which is which  ;).

...no vocals?...
Title: Re: MK-U47 - Official build thread
Post by: Inglev on March 22, 2015, 05:52:59 AM
My MK-U47 is complete. Did a comparison between the MK-U47 (which has a Thiersch Red Line), a Neumann U47 with a K47, and also my C12 clone (Tim Campbell capsule) and a Neumann M269 thrown in the mix for fun.
See if you can guess which is which  ;).

...no vocals?...

Only had time for a quick guitar test when I had the setup.... plus, I'm not the best singer  ;).
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on March 23, 2015, 06:56:21 AM
Thank you for the test, Inglev! Sounds nice.

Unfortunately there have been a few delays regarding the new batch, but everything's sorted out now and new kits should become available by the end of this week/early next week. Thanks everybody for your patience!

-Max

(https://dl.dropboxusercontent.com/u/35386715/MK-U47/MK-U47%20Kit%20copy.jpg)
Title: Re: MK-U47 - Official build thread
Post by: vinylwall on March 23, 2015, 06:59:52 AM
Fantastic!  I've been watching and ready to pull the trigger as soon as you say they are ready!  Jimi Ray
Title: Re: MK-U47 - Official build thread
Post by: stelin on March 23, 2015, 08:17:04 PM
"My MK-U47 is complete. Did a comparison between the MK-U47 (which has a Thiersch Red Line), a Neumann U47 with a K47, and also my C12 clone (Tim Campbell capsule) and a Neumann M269 thrown in the mix for fun."

I think nr 4 is the C12 with Tims capsule.
Nr 3 is the Neumann M269.
Nr 1 is the Neuman U47.
Nr 2 is the MK-U47.

- Stefan
Title: Re: MK-U47 - Official build thread
Post by: ioaudio on March 30, 2015, 10:58:27 AM
Hi Everybody,

now that the correct screws finally arrived, I'm completing the assembly of the new MK-U47 batch.
Shipping starts tomorrow, and I'm now open for orders. I'll go through my list, but if you inquired about a kit in the past it doesn't hurt to send me another email.
Kit/pricing and contact info: http://groupdiy.com/index.php?topic=35667.msg437839#msg437839

A quick snapshot during assembly:
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/Batch%202015.jpg)
Title: Re: MK-U47 - Official build thread
Post by: Melodeath00 on March 30, 2015, 12:04:58 PM
My MK-U47 is complete. Did a comparison between the MK-U47 (which has a Thiersch Red Line), a Neumann U47 with a K47, and also my C12 clone (Tim Campbell capsule) and a Neumann M269 thrown in the mix for fun.

Here's a sample of each microphone:
Mic 1: https://www.dropbox.com/s/ca6uywhw7f355g6/Mic%201.wav?dl=0
Mic 2: https://www.dropbox.com/s/adytkn2rw3lvdm8/Mic%202.wav?dl=0
Mic 3: https://www.dropbox.com/s/hnp82zqm8db11tr/Mic%203.wav?dl=0
Mic 4: https://www.dropbox.com/s/6nja0uu3uugep1l/Mic%204.wav?dl=0

See if you can guess which is which  ;).

Thanks for the test! Here's my guess after listening for about one minute...
Mic 1 and 3 sounded the closest to each other, so I will guess this is the U47 and the MK47. Mic 3 sounded more natural than Mic 1, so I will guess Mic 3 is the U47. Mic 1 had a resonance that made it sound not quite as good.

Mic 2 had a more extended top than those two, so I'd guess it's the M269. Mic 4 sounded more scooped in the upper mids, with more treble, so I'll guess it's the C12
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: o3misha on March 30, 2015, 12:22:00 PM
You mean the failure of the upper middle? I do not understand the " more scooped".
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: Melodeath00 on March 30, 2015, 12:52:35 PM
You mean the failure of the upper middle? I do not understand the " more scooped".
Yes, scooped usually means the sound has less energy in the mids frequency range
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: Inglev on March 31, 2015, 04:06:46 AM
Ok, thanks for the guesses  :).

Behind the secret mic-names are:
Mic 1 = M269
Mic 2 = U47
Mic 3 = MK-U47
Mic 4 = CIY C12

To me, the one that stands out the most is the C12, with a more "smiley mouth" EQ sound than the other 3. I was also surprised to find that the M269 was so similar sounding to the two U47's, even though I thought it was a bit more "closed" or "dull" sounding.

Let me also say that I don't think one mic is better than the other. They all have their own sound character which has its place. On different sources one might come out on top. Actually, just by using a different guitar, you might find you like another mic better.

Cheers
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: Melodeath00 on March 31, 2015, 05:07:37 PM
Ok, thanks for the guesses  :).

Behind the secret mic-names are:
Mic 1 = M269
Mic 2 = U47
Mic 3 = MK-U47
Mic 4 = CIY C12

To me, the one that stands out the most is the C12, with a more "smiley mouth" EQ sound than the other 3. I was also surprised to find that the M269 was so similar sounding to the two U47's, even though I thought it was a bit more "closed" or "dull" sounding.

Let me also say that I don't think one mic is better than the other. They all have their own sound character which has its place. On different sources one might come out on top. Actually, just by using a different guitar, you might find you like another mic better.

Cheers
That is really interesting! Thanks so much for the test. The only one I got right was the C12 haha, and looks like my favorite in this particular instance was the MK-47. Can you provide any details regarding your MK-U47 (which capsule?) and your U47 (all original? K47 or M7?)

EDIT: Sorry, I just revisited your post and saw you already provided those details. Thanks! I was surprised how close the M269 and MK-U47 sound. I found the U47 to sound a little bit brighter than the M269 and MK-U47, but perhaps that is due to the K47. Would love to hear a vocal comparison some time.
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: ioaudio on April 05, 2015, 03:28:52 PM
also check out the MK-U47 discussions over at realgear: http://realgearonline.com/board/1/pro-audio?q=mk-u47
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: stelin on April 06, 2015, 05:58:31 PM
Testing tubes in my MK-U47.
I have a bunch of WE408a tubes and two JAN 6028, and I can now test them one at a time.
I have replaced the capsule with a 68 pF capacitor and the heater for the unused tube with a 400 ohm resistor pack.
All tubes have been burned-in for at least 72 hours. I'm recording each tube on a separate track in Pro Tools, with the same gain.
First, I leave the mic alone for two minutes, then I tap on the mic,  pick it up and turn it upside down and back again.
So far I'm not impressed by the results.
The main problem is unreliability. Any one of the tubes can work well during a "session". Then I turn the PSU off and let it cool down. When I turn it on again it can be fine, but to often the noise level has gone up and it's acting like a broken tube (hiss, pops and clicks). It's all very random.
Also, when I turn the mic around and upside down (this is the same for all the tubes) I hear "pinging" sounds, like something is moving around or is loose inside the tube.
All the tubes I have tested (I have nine) are very microphonic. Tapping on the microphone house produces a sound almost as loud as when I have the capsule in the mic.
Is this normal for 408a/6028 tubes?
Have anyone tested any other 408a/6028, like the RCA 408a?

Any feedback would be appreciated.

- Stefan

Title: Re: MK-U47 - New batch available! - Official build thread
Post by: Category 5 on April 06, 2015, 06:27:59 PM
The WEs are the noisiest by far, though do sound good when you get a quiet pair.  I have found RCA, and GE to be very quiet from the get go.  I haven't found the Philips to be particularly noisy either once burned in but the Western Electrics have been problematic with the noise and pops you mention. 
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: stelin on April 06, 2015, 06:46:16 PM
Thank you, Category 5.

Do you have a good sources for the RCA and/or GE tubes?
I have been commissioned to build a MK-U47 for a studio here in Sweden, and I can not deliver the mic with the tubes I have today. They are simply to unreliable. I'm getting a bit desperate...  :)

- Stefan
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: Category 5 on April 06, 2015, 10:46:22 PM
Thank you, Category 5.

Do you have a good sources for the RCA and/or GE tubes?
I have been commissioned to build a MK-U47 for a studio here in Sweden, and I can not deliver the mic with the tubes I have today. They are simply to unreliable. I'm getting a bit desperate...  :)

- Stefan

Hey Stefan.  I bought all that I could find of the RCA and GE which was not many.  There is a guy selling some NOS GEs on ebay for a decent price.  Not sure where he is located.  I did find the Ericsson tubes to sound good and be quiet, but Kcatthedog got a pair he said were noisy like the WEs.

Are you saying the Philips are too noisy too after burn in?  I haven't had objectionable noise from those yet, at least after burn in.  You might try replacing the heater dropper before you go insane looking for RCAs.  Also, I've notice the need to reset the B+ voltage between tube swaps.  It can change quite a bit from set to set.

Keep in mind that noise performance should improve with both tubes in too, so don't make your final judgement without using the tubes in the mic as planned.  The MKU is not the quietest mic I've ever heard, but it is one of the nicest sounding!
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: stelin on April 07, 2015, 04:46:20 AM
The Philips have more noise than the WEs (in my case), after burn in. One of the Philips have more noise than the other.
The WEs are fine, except that they are unreliable. They can work fine and be very quit for hours, then the next time I turn the mic on they are hissing and spitting at a much higher level (it's not "clean" noise anymore).
It usually happens when I have moved the mic or changed its orientation. The hissing and spitting does not go away after the tube has warmed up. But it might be gone the next time I turn the mic on.
The MK-U47 sounds very fine! I have compared it to a genuine U47 and it's very hard to tell them apart.
The MK-U47 have a bit more noise than the U47, but the noise is (normally) low enough. I just need it to be more "stable".
I will check the heater voltage. If there is any noise coming from the heater dropper I might be able to spot it on the scope.

- Stefan

Title: Re: MK-U47 - New batch available! - Official build thread
Post by: vinylwall on April 11, 2015, 09:49:57 PM
Max, I received my MK-U47 kit today.  Very nice!!!!  I am still waiting for my Thiersch blue capsule and Tony's (Zayance) next batch of PSU boards, but here is the mic so far:
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: vinylwall on April 11, 2015, 09:50:25 PM
...and the rear side:
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: marcelkroese on April 16, 2015, 10:17:48 AM
Just recieved my two MK-U47 kits. Can't wait to start building. Pity I have to work tonight.......
They look great, Max!
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: marcelkroese on April 19, 2015, 02:41:56 PM
Waiting for a matched quad of these: http://valvetubes.com/6028-jan-6028-philips-ecg-usa.html Anyone expierences with these?
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: kidvybes on April 19, 2015, 06:39:44 PM
...these Sylvania GB-408A should be the gold-pinned variant...if they are in fact the same as the RCA gold-pin (visually they are identical), then definately worthy of an inquiry:
http://www.standardradioelec.com/GB-408A
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: marcelkroese on April 20, 2015, 09:50:14 AM
Am I on the right track here? Having a bit of an eye problem... Must be the age!
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: Banzai on April 20, 2015, 01:25:09 PM
Blue ok!
Green ok!
Red make extra connections
Yellow rewire pins

See attached pic for help (made with some computer trickery) ;)

Am I on the right track here? Having a bit of an eye problem... Must be the age!
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: marcelkroese on April 20, 2015, 02:05:21 PM
THANKS!!
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: andia on April 20, 2015, 03:08:29 PM
Blue ok!
Green ok!
Red make extra connections
Yellow rewire pins

See attached pic for help (made with some computer trickery) ;)

Am I on the right track here? Having a bit of an eye problem... Must be the age!

not so sure if yellow is wrong. maybe it doesn't matter with the heater, but if you look at the schematic, i think the first picture is right.
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: Banzai on April 20, 2015, 03:56:42 PM
Yeah, I went by this layout thing here.

I'm sure someone else can confirm, as the build pics have it wired like the first pic too!

not so sure if yellow is wrong. maybe it doesn't matter with the heater, but if you look at the schematic, i think the first picture is right.
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: andia on May 08, 2015, 01:24:12 PM
Hi,

I've completed the mics so far and am only waiting for the capsules to arrive. My Question is if I can burn in the tubes without the capsule or an equivalent capacitor attached? Would that harm the microphone?

thank you all, andi
Title: Re: MK-U47 - New batch available! - Official build thread
Post by: ioaudio on May 09, 2015, 03:12:42 AM
Yes, connect capsule front (green wire) to ground for the burn in.

-Max
Title: Re: MK-U47 - build thread
Post by: andia on May 09, 2015, 03:50:04 AM
this way for example? thanks again  ::)
Title: Re: MK-U47 - build thread
Post by: ioaudio on May 09, 2015, 04:25:41 AM
yes!
Title: Re: MK-U47 - build thread
Post by: Category 5 on May 09, 2015, 10:03:34 AM
Though debated it is generally required that you run signal through the tubes to burn them in properly.

Been thinking about building a test/burn-in jig myself. 
Title: Re: MK-U47 - Official build thread
Post by: opacheco on May 23, 2015, 01:17:17 PM
Hi Everybody,

now that the correct screws finally arrived, I'm completing the assembly of the new MK-U47 batch.
Shipping starts tomorrow, and I'm now open for orders. I'll go through my list, but if you inquired about a kit in the past it doesn't hurt to send me another email.
Kit/pricing and contact info: http://groupdiy.com/index.php?topic=35667.msg437839#msg437839

A quick snapshot during assembly:
(https://dl.dropboxusercontent.com/u/35386715/MK-U47/Batch%202015.jpg)

Dear audio,

Cold you send a quote by PM? I am very interested in get one.

In another hand: Are you compared with a REAL U-47? Do you have any discuss about in the forum or in your website(if you have one?)?

Thanks anticipated
Opacheco.
Title: Re: MK-U47 - build thread
Post by: marcelkroese on May 31, 2015, 02:48:13 PM
Hello!

Are there fellow diyers who have come up with a clever way of attaching and aligning a Flea capsule holder to the MK-U47 body other than cutting the plastic screw? I want to use just one spacer. If so, I am curious of what you came up with.

All the best,

Marcel
Title: Re: MK-U47 - build thread
Post by: ioaudio on June 01, 2015, 04:24:40 PM
Hi Marcel,

that's why i provided a nylon screw - so it can be easily cut for the various heights!
So just cut to required length - not too short :-)

-Max
Title: Re: MK-U47 - build thread
Post by: marcelkroese on June 01, 2015, 04:48:34 PM
I was aware of that, Max. Thank you. I tried and now I'm looking for a more solid solution.  Just wondering where other DIY'ers came up with.
Title: Re: MK-U47 - build thread
Post by: Category 5 on June 01, 2015, 05:11:02 PM
Screw cuts easily if needed but with the largest Thiersh mount you need all 4 inserts to reach the correct vintage height for the M7 so no trimming needed. 
Title: Re: MK-U47 - build thread
Post by: kosi on June 05, 2015, 06:48:29 PM
My first one is finished , this was a LONG wait for the M7 !

I'm not sure about the wires of my Thiersch M7 Blueline,  is this correct ?
The omni switch doesn't work, mic stays in cardioid,
and when I touch the body, I get very loud noise.
Any tips ?

the mic itself works perfect and is very quiet ! I use RCA408.
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on June 05, 2015, 06:50:41 PM
Be sure you are testing the mic INSIDE the body and head grille! Or you will get all manner of ugly noises...

hth

Mike
Title: Re: MK-U47 - build thread
Post by: kosi on June 05, 2015, 06:55:29 PM
Yeah I know,
I took the head grille down for the photo.
Title: Re: MK-U47 - build thread
Post by: marcelkroese on June 06, 2015, 06:00:39 PM
Hi Kosi,

That looks great! Got my own M7 Blue Lines today. Very excited. I was also wondering about the wiring, but I think it doesn't matter either way around. The glass switch needs some tweaking to allign and get it working properly in line with the magnet on the basket's switch. The capsule will react on any contact made to the body's mic since it's attached to that. That's why you need a good shockmount to avoid this. Let us know if you come up with tips and tricks.

Best,

Marcel
Title: Re: MK-U47 - build thread
Post by: kosi on June 07, 2015, 07:12:24 PM
 8)

All is good, after 48 hours burn in, the mic is very quiet.

And I found out about my Omni problem: When I move the switch slowly from left to right, the mic switches after one centimeter to Omni.  When I move it all the way over to the right, the mic goes back to cardioid.
 I tried to adjust it, but I didn't find out, how, and I don't want to reopen and unsolder the whole HI Z area.
But I can easily live with that, I will use it in cardioid most of the time anyway.

The touch sensitivity of the body is still there, it's a little bit too much for my taste, but tomorrow I make a real world test in the studio.

All in all, this was a super nice build, I had some problems with the mounting of the HI Z area and the position of the little magnetic switch, took me quite awhile to do it (nearly) right.

A BIG thank you to Max in Vienna, you are my hero :)
And thanks to everyone in this thread for sharing their knowledge and findings !
Title: Re: MK-U47 - build thread
Post by: Baltazar on June 09, 2015, 12:56:27 PM
My first one is finished , this was a LONG wait for the M7 !

I'm not sure about the wires of my Thiersch M7 Blueline,  is this correct ?
The omni switch doesn't work, mic stays in cardioid,
and when I touch the body, I get very loud noise.
Any tips ?

the mic itself works perfect and is very quiet ! I use RCA408.

Looks very nice!!
What height did you use for the capsule holder, cause that is thiersch capsule holder?
Do you have a picture of your PSU? Need inspiration  ::)
Title: Re: MK-U47 - build thread
Post by: kosi on June 09, 2015, 01:13:08 PM
Yes, this is the Thiersch capsule holder.
I didn't use any of the distance pieces, the normal height looked good to me, so I just kept it like that.

I use for my PSU an old Gefell N61 housing, which was not such a good idea. It has many holes in the wrong places.
Then I also made some logistic faults, so I ended up with a very DIY looking PSU...
Will post a pic, when I'm in the studio.

After my first test in the studio, I am very satisfied with the touch sensitivity of the body, my original U67 has the same level.
I guess I never noticed before, cause I never held the U67 in my hand...
I use the big Rycote mount and in this one, the 47 is VERY unsensitive to touching, so pleasant surprise.

Unfortunately, the noise level is pretty much higher than my U67, so I have to look around for new tubes. Difficult job.
But nevertheless, the sound is superb and I won't hesitate to use it in productions from now on.

When I have time, I will fetch a few U47s from friends (actually I know 5 U47 users) and compare them.
I already did some comparisons with my U67 and it left me all smiling :)

Title: Re: MK-U47 - build thread
Post by: kosi on June 10, 2015, 12:23:38 PM
Here my rough PSU
Title: Re: MK-U47 - build thread
Post by: kosi on June 10, 2015, 12:27:11 PM
back (or front)
Title: Re: MK-U47 - build thread
Post by: chefducuisine on June 10, 2015, 03:43:42 PM
kosi,

you can hear mine here (together with two DIY U87 as room mics).
I ended up with using WE tubes...
http://groupdiy.com/index.php?topic=59704.0 (http://groupdiy.com/index.php?topic=59704.0)
Title: Re: MK-U47 - build thread
Post by: marcelkroese on July 03, 2015, 09:53:39 AM
Burn Baby Burn
Title: Re: MK-U47 - build thread
Post by: Pip on July 03, 2015, 11:24:51 AM
Burn Baby Burn

How hot is the area where the drop-down resistor is attached to the base getting?
Title: Re: MK-U47 - build thread
Post by: kosi on July 03, 2015, 11:27:12 AM
HOT !
But I can touch it

recording as we speak, btw
Title: Re: MK-U47 - build thread
Post by: marcelkroese on July 03, 2015, 11:33:06 AM
Very hot! Can just bear it.
Title: Re: MK-U47 - build thread
Post by: Pip on July 03, 2015, 08:30:09 PM
HOT !
But I can touch it

recording as we speak, btw

Glad to hear it! I have had this in use for awhile and was just not sure it was supposed to get as warm as it does. I noticed Max went with a 10Watt 1.5K resistor this time.

 I am in the process of burning in some new tubes. Just because there is a difference in sonics and gain between the Phillips/JAN and the WE. I just cant make up my mind. Both have there merits and drawbacks.
Title: Re: MK-U47 - build thread
Post by: Baltazar on July 23, 2015, 04:39:27 PM
Finished, mine a couple of days ago, redline capsule, philips tubes and a thick film resistor for the negative biasing resistor.

Did a really quick comparing against our UM57, i know it's not the same mic at all but it has a nice character and works really good. Some quick thoughts:
The UM57 has smoother top, bottom is pretty similar, even though the mk-u47 goes a little deeper, mid not as present or nice as the mk-u47.

What i'm going to do is try some other tube brands and different neg biasing resistors. I also got an old Bosch I really wanted to use for coupling cap, but it was too big to fit :(. Going to try to modify the inside of the mic to make it fit...

I would want to smooth the high out a bit, some letters really slams through a bit too much now in my opinion.


Anyway, thank you Max for an fantastic design, kit and quick shipping!!
Title: Re: MK-U47 - build thread
Post by: ioaudio on July 23, 2015, 04:51:02 PM
Thanks Baltazar!

before you start drilling holes I'd recommend giving the blue (PVC) line a chance.
I'm pretty sure the bosh cap wont change the timbre enough, based on how you describe the sound.
If you decide to go for it, Thiersch's capsules hold their value well and some even prefer the more modern sounding red line.

-Max
Title: Re: MK-U47 - build thread
Post by: Baltazar on July 23, 2015, 04:59:29 PM
Thanks Baltazar!

before you start drilling holes I'd recommend giving the blue (PVC) line a chance.
I'm pretty sure the bosh cap wont change the timbre enough, based on how you describe the sound.
If you decide to go for it, Thiersch's capsules hold their value well and some even prefer the more modern sounding red line.

-Max

Wow, that reply was even quicker than you ship! :)

Then i might just place an order for a blue line... Or maybe build another one...

But that bosch cap looks so good.... :)

Also want to add i had no problem with unreliability on the philips tubes, the noise floor is very low.

Edit: Added a picture of my psu..
Title: Re: MK-U47 - build thread
Post by: Pip on August 22, 2015, 02:48:03 PM
So in the interest of not taking up more space then necessary I have come to, at least for now, some tube conclusions:

http://groupdiy.com/index.php?topic=47112.msg764053#msg764053

http://groupdiy.com/index.php?topic=47112.msg764111#msg764111
Title: Re: MK-U47 - build thread
Post by: Baltazar on August 25, 2015, 10:10:35 AM
Ok, couldn't resist to place and order for a Blue line, so i did...

Difference is quiet big, s:es and k:s are softer and over all a lot less sibilant.

The blue line is definitely the capsule to go for in this build if you primary plan to use it for vocals.


I have to say I'm not a huge fan of the magnet solution to change the characteristic of the mic, worked perfect before. But cant get it to work perfect again.. its VERY sensitive and precise and the feeling of the "switch" is not very smooth. But thats my only concern around this build!  :D
Title: Re: MK-U47 - build thread
Post by: stelin on September 04, 2015, 03:03:08 PM
I have delivered two MK-U47s to Pama Studio 3 in Sweden today.
We spent the afternoon comparing the two MK-U47s to Pamas original U-47.
The general conclusion was that it was very hard to distinguish the original U-47 from the two MK-U47s. There where small differences, but no more than you would expect from different copies of "the real thing".
Title: Re: MK-U47 - build thread
Post by: ioaudio on September 16, 2015, 02:28:01 PM
Nice! Do you happen to know which capsule sits in the original U47?

-Max
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 16, 2015, 03:17:25 PM
Max, at one point you mentioned you were working on an M7 of your own, as well as a PSU for this kit.

Are those still in the offing?

By the way, I'm sure you have spent some time in Klaus' forum for microphones. He says no one has nailed a real M7 in years. He thinks it's because the PVC material has changed. Just wondering if you were going to continue this research, and also suggest you contact him as he might be willing to offer suggestions/guidance if you wanted it.

Hope this isn't too far OT; just wanting to make the best MK-U47 possible (hint, hint!)

:)

Mike
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 16, 2015, 05:14:02 PM
A quick question regarding the PSU - Max do you have a schematic for it specifically, or you are recommending the Zayance or a real Neumann PSU?

I'm tempted to go PTP on this one, as I want to mount the resistors off-board anyway; I'm not certain what value the Zayance PCB will provide with more than half the components not even mounted.

I do have a question regarding the LED that is on the Zayance PCB - how does this not get fried? I thought LED's were around 5V or such; I can't see how the voltage gets dropped to support it...or are there some high-power LEDs out there of 105V? I tried doing the math on it and can't figure this...any thoughts, anyone?

Thanks

Mike
Title: Re: MK-U47 - build thread
Post by: stelin on September 17, 2015, 06:20:45 AM
Max, the original U47 has a K47 capsule. The two MK-U47s have Thiersch Red Line capsules.
Title: Re: MK-U47 - build thread
Post by: Pip on September 17, 2015, 07:39:41 PM
A quick question regarding the PSU - Max do you have a schematic for it specifically, or you are recommending the Zayance or a real Neumann PSU?

I'm tempted to go PTP on this one, as I want to mount the resistors off-board anyway; I'm not certain what value the Zayance PCB will provide with more than half the components not even mounted.

I do have a question regarding the LED that is on the Zayance PCB - how does this not get fried? I thought LED's were around 5V or such; I can't see how the voltage gets dropped to support it...or are there some high-power LEDs out there of 105V? I tried doing the math on it and can't figure this...any thoughts, anyone?

Thanks

Mike

There is a PSU schematic somewhere here. I love the PCB that Zayance sells. There is a drop down resistor incorporated in the Zayance PCB for the LED.
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 17, 2015, 08:04:22 PM
Thanks Pip. I have one coming, although I am probably going to go PTP on this one since I'm already going to mount the resistors off-board anyway.

EDIT: tried figuring the LED maths but I think I did it wrong; removing calculations...
Title: Re: MK-U47 - build thread
Post by: ioaudio on September 18, 2015, 09:25:53 AM
Max, at one point you mentioned you were working on an M7 of your own, as well as a PSU for this kit.

Are those still in the offing?

By the way, I'm sure you have spent some time in Klaus' forum for microphones. He says no one has nailed a real M7 in years. He thinks it's because the PVC material has changed. Just wondering if you were going to continue this research, and also suggest you contact him as he might be willing to offer suggestions/guidance if you wanted it.

Hope this isn't too far OT; just wanting to make the best MK-U47 possible (hint, hint!)

:)

Mike


Hey Mike,

indeed I'm working on my take on the M7 capsule, on and off since nearly three years now.
I'm experimenting with all kind of different PVC films in various thickness, often sourced from outside EU for regulation issues.
I have come close to what i want it to sound, a pristine original Berlin M7 i use as a reference, but there's still a small difference, and i want to get it 100% right.  Testing is done by myself and by three sound engineers who have a U47s with original M7 capsules.
I recently found a Swiss manufacturer for specialty films and they will send me a couple of samples next week, I'll make an appointment with the research lab for the gold evaporation after that. I have a good feeling with the new film but we'll see.

regarding the PSU:
Since the MK-U47 works like the original, just follow the original PSU plans. Additionally the schematics can be found in the MK47 thread (minus the switch). Most of my costumers build with Zayance's PCB.
I recommend the LED because it also shows if there's any current left in the capacitors after switching off (the LED fades as it drains)
Led current/voltage drop resistor is simply calculated by ohms law (google led resistor calculator)

-Max
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 18, 2015, 11:26:04 AM
Max this is so exciting! Thanks for the update!!

Yes of course I understand how to calculate for one LED; the issue is I don't know what the voltage is coming into that leg of the circuit. I guess I'll just trust Zayance's calculation for now.

I'm going to do a PTP using the MK47 schematic as you suggested.

Thanks much, and looking forward to the fruit of your labor!!

Best,

Mike
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 20, 2015, 03:15:40 AM
OK knowledgeable minds, show me the error in my calcs.

I'm trying to understand why the MK-47 specifies a 100K 1W resistor for the LED.

Let's assume the voltage is 105v. It's probably a bit higher in this leg of the circuit, but let's go with 105 for the moment. Actually since in parallel circuits all voltages are the same, it would be 105V, right? If the PSU is calibrated of course.

Let's assume a 5V, 20mA LED (pretty standard).

This means we need to drop 100V to give the LED it's requisite 5V. So far so good?

This gives us an R = V/I value of 100V/.02A = 5K.

Power rating would be = V*I = 100*.02 = 2W. Double it for safety, 4W, ~5W.

Now let's look at the stock 100K resistor.

Assuming the 100K resistor also dropped 100V, the current would be = V/R = 1mA. The power would be = V*I=100*.001=.1W

So basically this 100K resistor will work fine for very low current LEDs of around 1mA or so? In my case I have a 6V LED that uses 15mA, so I'll have to use a higher bigger resistor for my project instead. I'm using the Antek toroid, which puts out a bit more juice than the Triad, so I think I'll be ok in that regard.

In my exact case, I've done a simulation of the PSU using a link in this thread, and using a value of 470R instead of the 680/330 combo. Pot value at 220R gives 105.2V.

I drop 99V across my resistor, at 15mA.

This means I need R=V/I = 99/.015A= 6.6K resistor. W=V*I = 99*.015 = 1.5W, double for safety and that gives me a 6.6K resistor at 3W.

Can anyone check me on this? Am I in the right ballpark?

Thanks,

Mike
Title: Re: MK-U47 - build thread
Post by: ioaudio on September 25, 2015, 02:42:12 AM
Sorry for the late reply.
Yes, stock the LED works at a low current of 1mA, a little dimmed but still clearly visible.
15mA would be quite a waste of power.
Title: Re: MK-U47 - build thread
Post by: ioaudio on September 25, 2015, 02:47:02 AM
I just read the thread over at Klaus' Forum.
I do not agree that the Thiersch blue line capsule is "project-studio quality".
Aside from the various great sounding MK-U47s, this capsule is/was used in high end builds from Wagner, Grosser, Wunder etc, hardly "project-studio quality" !

-Max
Title: Re: MK-U47 - build thread
Post by: Category 5 on September 25, 2015, 07:36:03 AM
I just read the thread over at Klaus' Forum.
I do not agree that the Thiersch blue line capsule is "project-studio quality".
Aside from the various great sounding MK-U47s, this capsule is/was used in high end builds from Wagner, Grosser, Wunder etc, hardly "project-studio quality" !

-Max

Agreed Max.  Klaus may have his own interests in mind when criticizing the works and products of others.  Both Blue and Redline capsules are premium performance products, just like the genuine Neumann capsules are (i.e. K49)

Title: Re: MK-U47 - build thread
Post by: Pip on September 25, 2015, 11:02:59 PM
I just read the thread over at Klaus' Forum.
I do not agree that the Thiersch blue line capsule is "project-studio quality".
Aside from the various great sounding MK-U47s, this capsule is/was used in high end builds from Wagner, Grosser, Wunder etc, hardly "project-studio quality" !

-Max


I agree the  Thierch Elektroakustic (TE) capsule is not an amateur capsule. I also don't know who uses what in their mics as an example most of the companies say they make their own Wagner especially.  I also don't know what is meant by the phrase project studio quality? As most of the records recorded today are recorded in project studios. So maybe that's a good thing?!

I don't think Mr. Heyne is a big fan of the M7 capsule.  I haven't read his comments in a long time  but I distinctly remember getting the impression that he was more of a K47 guy. He also like the rest of us has a definite sonic character he has decided over years and years of listening that he sees as a Holy Grail sound. Which I think he will agree that not all original U47's share by any means.

There is something,  IMO that is more modern and relevant to today's production  desires  that is brought by the K47 over the M7 and there is also a definite difference between the East (Geffel) vs West (Neumann ,Berlin) M7 capsules.  As there is a  difference between the Dale M7 and the Cathedral Pipes M7 and the Beesneez M7 and the TE M7 both RED and Blue, etc...  I  also feel they each have their own use and shine in different ways on different things.

 I have built all of my U47 copies with M7 design capsules and IMO I prefer the TE Blue Line for what I do. But that being said it is because of a definite sonic signature it is not because of its flat response curve or its truthiness to the source. If you want a more accurate U47 I think you do want one with a K47 or even a Stephen Paul or a Klaus Heyne mod.

To end I will say it again it always makes me giggle when anybody says "thats the mic The Beatles and Frank Sinatra used", because at the end of the session they where The Beatles and Frank Sinatra!
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 26, 2015, 08:00:43 PM
OK I  have requested a Blueline!!

Here's a question. WHY do we keep the dropping resistor inside the bottom bell of the microphone, heating up the microphone - just because Neumann did it?

Would it not make more sense to place this resistor in the PSU instead, keeping the microphone cool? Let the PSU heat up instead of the mic?  Or are we just deliberately trying to cook our precious capsules?

Would there be any sonic problem with mounting that dropping resistor inside the PSU instead of the mic? Has anybody tried this?

Thanks.

 :o
Title: Re: MK-U47 - build thread
Post by: Pip on September 26, 2015, 10:01:07 PM
OK I  have requested a Blueline!!

Here's a question. WHY do we keep the dropping resistor inside the bottom bell of the microphone, heating up the microphone - just because Neumann did it?

Would it not make more sense to place this resistor in the PSU instead, keeping the microphone cool? Let the PSU heat up instead of the mic?  Or are we just deliberately trying to cook our precious capsules?

Would there be any sonic problem with mounting that dropping resistor inside the PSU instead of the mic? Has anybody tried this?

Thanks.

 :o

Proximity to the circuit is all and by that I mean where it is and what it is. If you were to do something different with the configuration you stray from the original design you also bring in a whole new set of variables including the voltage loss and capacitance of the cable length. Part of what makes this mic this mic is the single supply voltage concept for example there is voltage sag inherent in this design that comes into play as the SPL goes up. But why use a drop down resistor at all why not use a dedicated power supply for the necessary 40VDC for the filament no reason other than it would be a variant on the original design.

As to cooking the capsule with heat, I don't think it has any bearing on the issue. Our capsules are more in danger from handling issues and humidity issues, the most devastating one being spit with food particles and other such niceties which then allows for gunk attachment bringing on frequency attenuation and decrepitude. The heat factor has more to do with the noise specs of the mic is my guess as resistance heat dissipation=noise. I know that when that drop down resistor is not right it becomes an audio artifact making machine! If you use Teflon coated wire you will have no heat problem there either.
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 26, 2015, 10:55:18 PM
Good points Pip!

Yes fidelity to the original design is a consideration of course. I have a PSU from a well-known mic builder and he uses a zener in his PSU. Mic is very quiet anyway!

I guess my concern stems from posts wherein people have stated, "be sure to hang your U47 upside down to avoid sending undue heat to the capsule." I know that heat is a killer when it comes to electronics. In fact I read somewhere that every 10 degree increase in heat halves the life of your components. Dunno if that's true, but makes sense.

Plus if one has the PVC capsule, that is already prone to aging and getting brittle, just seems a bit like spiting fate to use so much heat.

Thanks.

Mike
Title: Re: MK-U47 - build thread
Post by: Pip on September 26, 2015, 11:06:55 PM
Good points Pip!

Yes fidelity to the original design is a consideration of course. I have a PSU from a well-known mic builder and he uses a zener in his PSU. Mic is very quiet anyway!

I guess my concern stems from posts wherein people have stated, "be sure to hang your U47 upside down to avoid sending undue heat to the capsule." I know that heat is a killer when it comes to electronics. In fact I read somewhere that every 10 degree increase in heat halves the life of your components. Dunno if that's true, but makes sense.

Plus if one has the PVC capsule, that is already prone to aging and getting brittle, just seems a bit like spiting fate to use so much heat.

Thanks.

Mike

Hanging the mic upside-down to avoid heat hurting capsule pure wives-tale stuff IMHO. The only reason to hang it that way is so it doesn't block the view of the music-stand or allows for a better placement. I also have noticed that there is something that psychologically aids singers when its that way they tend to sing in a more physically relaxed manor but that is not science and it is just my feeling.
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 26, 2015, 11:20:37 PM
Well...not to be contrary...but of course heat rises, and I'm sure the capsule could do without all that extra heat...

I loved your comment about singers being more relaxed with the mic upside down...
Title: Re: MK-U47 - build thread
Post by: Category 5 on October 20, 2015, 10:47:35 AM
Well...not to be contrary...but of course heat rises, and I'm sure the capsule could do without all that extra heat...

I loved your comment about singers being more relaxed with the mic upside down...

The capsule mount is isolated so really the only heat the capsule sees is the heat from the air that surrounds it.  Put your hand on the grill and you'll see there really isn't much heat up there at all.  Maybe it's a little warmer than ambient, but nothing that I would expect to significantly impact the performance or longevity of the capsule (even PVC).  If you want to preserve the longevity of the capsule, bag the mic before you disconnect power, and store it in a cool dry place.  The bell on the other hand will get almost too hot to touch, and I rather like it.  To me it says "I'm all warmed up and ready to impress"

You could also put the dropper in the PSU and wire the heater through one of the redundant ground pins (or use a 7 pin insert for the mic).  That would eliminate most of the heat from the mic side, but again I don't think there is really much benefit as far as longevity is concerned.
Title: Re: MK-U47 - build thread
Post by: stribor1 on October 21, 2015, 07:24:40 AM
Finally put my MKPSU together. Everything working fine I got it tuned to 105V, but it keeps popping fuses, apparently only when I turn it on or off. When I get it working it is stable, then I power it off and when I power it on the fuse is blown (doesn´t happen every time but very frequently, like  50% even more)
I have 220V power and use a slow blow 125mA fuse. The Mains transformer is is a 30VA toroidal one with a 200V output and 6,3V pilot light output purchased from TubeTown.de
I got the 220V leads connected to my euro-power connector which also contains a fuse holder.

I put a 200mA slow blow fuse in there and the problem is gone, but 200mA gives 44VA on 220V and I´m afraid that the mains transformer might die on me.
Any idea? Is it possible that this is caused by a bad mains transformer?
Thanks,
J.
Title: Re: MK-U47 - build thread
Post by: stelin on October 23, 2015, 01:47:41 PM
I have built three PSUs for my MK-U47s. One of the PSUs has blown the (0.125 amp) fuse one time.

The size of the fuse does not change how much current the transformer draws. It only sets a limit: If the current is too high the fuse will blow. It’s a protection against a short circuit, when the 220 volts AC, 200 volts AC secondary or 105 volts DC gets connected directly to ground.

In Sweden we now have 230 Volts in the power outlets (it used to be 220 volts). If I remember right, there are three ways you can connect the transformer from TubeTown (I’m using the same one): 220, 230 and 240 volts.
I have used the 240 volts lead. That means that the voltage on the secondary side will be a little bit less than if you use the 220 or 230 volt lead.

When you turn on the PSU it will draw a lot more current for a short moment. That’s because the capacitors in the PSU are empty and they must be “filled up” with charge. Also, the microphone will draw a bit more current in the first five seconds or so because the heater in the tubes have very low resistance before they start to glow (the resistance increases when the wire in the heater warms up).

I suspect that the 0.125 amps recommendation is based on how much current the microphone draws when it is “warmed up and in operation”.

I changed the fuses in my PSUs to 0.3 amps. I have not had any blown fuses since I did that.

- Stefan
Title: Re: MK-U47 - build thread
Post by: stribor1 on October 24, 2015, 10:24:09 AM
Thanks Stefan,
I´m using the 200mA fuse now and no blown fuses so far.
I know that the fuse is not impacting the current draw, only limiting it and I also figured that the initial impulse when powering on is probably blowing the 125mA fuse. I was only concerned that the 200mA fuse is would limit the current past the power rating of the transformer (could reach 44VA with this fuse) but it is not likeley that a permanent 200mA current draw should occur.

The mic is working fine in cardio btw, but no omni, but I already know the reason and will fix this shortly.
Using Philips Miniwatt tubes and burn in is still ongoing. Have some Tungsols, they are next. Trying to get some WE´s.

Title: Re: MK-U47 - build thread
Post by: Pip on October 24, 2015, 02:11:40 PM
Thanks Stefan,
I´m using the 200mA fuse now and no blown fuses so far.
I know that the fuse is not impacting the current draw, only limiting it and I also figured that the initial impulse when powering on is probably blowing the 125mA fuse. I was only concerned that the 200mA fuse is would limit the current past the power rating of the transformer (could reach 44VA with this fuse) but it is not likeley that a permanent 200mA current draw should occur.

The mic is working fine in cardio btw, but no omni, but I already know the reason and will fix this shortly.
Using Philips Miniwatt tubes and burn in is still ongoing. Have some Tungsols, they are next. Trying to get some WE´s.

Are your Philips Miniwatts microphonic? When you tap the mic body do they make a ping sound?

After much research my suggestion is you want to look for made in USA WE tubes with the large font. I believe these are older than the others available and there is no doubt in my mind anymore that they are the lowest noise of the WE's. If you can find some Ericsson 408a's they are the best noise to microphonic in my experience and sound great. The Philips TS62 Miniwatts sound the best out of all I have tested but they are the most microphonic.
Title: Re: MK-U47 - build thread
Post by: stribor1 on October 24, 2015, 03:54:22 PM
Thanks Stefan,
I´m using the 200mA fuse now and no blown fuses so far.
I know that the fuse is not impacting the current draw, only limiting it and I also figured that the initial impulse when powering on is probably blowing the 125mA fuse. I was only concerned that the 200mA fuse is would limit the current past the power rating of the transformer (could reach 44VA with this fuse) but it is not likeley that a permanent 200mA current draw should occur.

The mic is working fine in cardio btw, but no omni, but I already know the reason and will fix this shortly.
Using Philips Miniwatt tubes and burn in is still ongoing. Have some Tungsols, they are next. Trying to get some WE´s.

Are your Philips Miniwatts microphonic? When you tap the mic body do they make a ping sound?

After much research my suggestion is you want to look for made in USA WE tubes with the large font. I believe these are older than the others available and there is no doubt in my mind anymore that they are the lowest noise of the WE's. If you can find some Ericsson 408a's they are the best noise to microphonic in my experience and sound great. The Philips TS62 Miniwatts sound the best out of all I have tested but they are the most microphonic.

Yes, quite microphonic. They are cooking for some 10 hours so I´m still burning them in and hope this will improve. I´m very happy with the sound (classical guitar sounds magic, voice very natural and warm), but didn´t compare them yet to other tubes.
Found some 50ies WE 408A in nostubestore.com (got the miniwatts there as well, gold pins O-getter), the guy has just 4 left don´t know if they are paired still waiting for a reply.
Title: Re: MK-U47 - build thread
Post by: Pip on October 30, 2015, 09:20:38 PM
Thanks Stefan,
I´m using the 200mA fuse now and no blown fuses so far.
I know that the fuse is not impacting the current draw, only limiting it and I also figured that the initial impulse when powering on is probably blowing the 125mA fuse. I was only concerned that the 200mA fuse is would limit the current past the power rating of the transformer (could reach 44VA with this fuse) but it is not likeley that a permanent 200mA current draw should occur.

The mic is working fine in cardio btw, but no omni, but I already know the reason and will fix this shortly.
Using Philips Miniwatt tubes and burn in is still ongoing. Have some Tungsols, they are next. Trying to get some WE´s.

Are your Philips Miniwatts microphonic? When you tap the mic body do they make a ping sound?

After much research my suggestion is you want to look for made in USA WE tubes with the large font. I believe these are older than the others available and there is no doubt in my mind anymore that they are the lowest noise of the WE's. If you can find some Ericsson 408a's they are the best noise to microphonic in my experience and sound great. The Philips TS62 Miniwatts sound the best out of all I have tested but they are the most microphonic.

Yes, quite microphonic. They are cooking for some 10 hours so I´m still burning them in and hope this will improve. I´m very happy with the sound (classical guitar sounds magic, voice very natural and warm), but didn´t compare them yet to other tubes.
Found some 50ies WE 408A in nostubestore.com (got the miniwatts there as well, gold pins O-getter), the guy has just 4 left don´t know if they are paired still waiting for a reply.

Yeah sadly I had no luck with the microphonics getting better after 3 days of burn in. That said, I think they are the best sounding of all the 408a's I have tested so I suggest recording for a bit and see if they have any noticeable problems. If you only hear problems when you touch the mic I ask myself is this a problem.
Title: Re: MK-U47 - build thread
Post by: Bowie on October 31, 2015, 04:25:09 PM

Yeah sadly I had no luck with the microphonics getting better after 3 days of burn in. That said, I think they are the best sounding of all the 408a's I have tested so I suggest recording for a bit and see if they have any noticeable problems. If you only hear problems when you touch the mic I ask myself is this a problem.

  Microphonics generally don't improve.  If they start out bad, chances are that they'll get worse from heating and cooling cycles (warpage).  The problem you might end up having with your tubes is that a vocal/instrument can vibrate a mic more than you might think, leaving a trace of microphonic reverb in your tracks. 
Title: Re: MK-U47 - build thread
Post by: Category 5 on October 31, 2015, 05:37:04 PM
The polystyrene capacitor can also be responsible for microphonics.  Make sure the leads are short and tight. 
Title: Re: MK-U47 - build thread
Post by: Pip on November 01, 2015, 01:30:31 AM
The polystyrene capacitor can also be responsible for microphonics.  Make sure the leads are short and tight.

Very true indeed. But this is not that, every Philips Miniwatt TS62 408a (at least a dozen pairs)  I have tested was quiet electrically, no hissing or popping,  but microphonic. They sound damn good though until you tap the body and then it is a high pitched ring. Yes I am worried that if the mic body is concussed hard enough by a sound wave it might get into the recording but so far I have not noticed anything. But have as of yet not used this configuration for room mic on drums or in front of a guitar cabinet.
Title: Re: MK-U47 - build thread
Post by: gbruler on November 03, 2015, 08:47:32 AM
Hello everyone,

Can someone please explain to me how to connect the microphone to the pattern switch? I can't figure this out.

Thanks
Title: Re: MK-U47 - build thread
Post by: djn111 on November 04, 2015, 02:48:42 PM
Hi,

What do you mean,  the place of the reed switch ? Be aware the magnetic field of the magnet makes circles, so the middle is not the strongest field. I will post some pictures tommorow how I solved it.

Djn
Title: Re: MK-U47 - build thread
Post by: gbruler on November 04, 2015, 03:44:37 PM
Hi,

What do you mean,  the place of the reed switch ? Be aware the magnetic field of the magnet makes circles, so the middle is not the strongest field. I will post some pictures tommorow how I solved it.

Djn

That will be great, I am really not sure how to work with this thing..

Thanks!
Title: Re: MK-U47 - build thread
Post by: djn111 on November 05, 2015, 05:00:21 AM
The promised foto's and explanation:

(http://i46.photobucket.com/albums/f146/djn111/Magnet_zpslevt8sjr.jpg)

First of all, the magnet and the reed switch should not be in the middle, the magnetic field is the strongest about the edge of the magnet.

How to test if you did it right or not.

I, first put in the mounting plate of the capsule, low Z board, and lined it up in the headbasket, now you can mark out with a marker, where the magnet is in the cardiod and round position.

(http://i46.photobucket.com/albums/f146/djn111/Top%20view_zpsjrq6s9z1.jpg)

After that I mounted the reed switch with two little M2 bolds, and al the rest normal. now you can check with a multy meter if it works. But to be shure, I put the whole thing together, and checked again.

(http://i46.photobucket.com/albums/f146/djn111/Side%20view_zpsfyofvnf9.jpg)

Because I used the two little bolds, I can measure the working of the switch with the head basket mounted, hope this helps.

And when you are shure everything is working properly, switch the bolds one by one for the original ones, and mount the rest of the parts.

Djn
Title: Re: MK-U47 - build thread
Post by: gbruler on November 13, 2015, 08:06:51 AM
The promised foto's and explanation:


First of all, the magnet and the reed switch should not be in the middle, the magnetic field is the strongest about the edge of the magnet.

How to test if you did it right or not.

I, first put in the mounting plate of the capsule, low Z board, and lined it up in the headbasket, now you can mark out with a marker, where the magnet is in the cardiod and round position.

After that I mounted the reed switch with two little M2 bolds, and al the rest normal. now you can check with a multy meter if it works. But to be shure, I put the whole thing together, and checked again.

Because I used the two little bolds, I can measure the working of the switch with the head basket mounted, hope this helps.

And when you are shure everything is working properly, switch the bolds one by one for the original ones, and mount the rest of the parts.

Djn

Hey Thank you very much for that, I finally had time to check this out, and apparently I broke it, and I guess that is why it didn't work, so I'll get some new ones and try to fix it.

Thanks again!
Title: Re: MK-U47 - build thread
Post by: Energizer on December 26, 2015, 07:06:46 AM
Hi, I hope everyone is enjoying this year's end celebrations  :)

A couple months ago I built a pair of MK-U47 (Thiersch Red Line capsules and Zayance's PSUs).
The first mic works flawlessly but I noticed the noise floor was significantly higher on the second one.
Then the situation got worse as I get loud scratching noises and all kinds of clicks and pops that seem to come back each 5 minutes or so. The sound seems to be OK but these noises make the mic unusable...

Here are some audio samples :
https://www.dropbox.com/s/opvij2ztgbmzxos/mk-u47%20noise%201.wav?dl=0 (https://www.dropbox.com/s/opvij2ztgbmzxos/mk-u47%20noise%201.wav?dl=0)
https://www.dropbox.com/s/hcwea75kdn1gigl/mk-u47%20noise%202.wav?dl=0 (https://www.dropbox.com/s/hcwea75kdn1gigl/mk-u47%20noise%202.wav?dl=0)

So I was wondering if someone had experienced similar issues ?
Could it be a faulty tube, or maybe a problem with the reed switch ?

Thank you all very much for your help  ;)

Brice
Title: Re: MK-U47 - build thread
Post by: djn111 on December 26, 2015, 09:24:59 AM
Hello,

I would start, with swaping both tubes. Between mic's if the problem swaps with it, you can suspect the tubes.

Djn
Title: Re: MK-U47 - build thread
Post by: Sredna on December 30, 2015, 07:18:09 PM
Yes, probably the tubes.
I bought 10 pcs and had to try a good while to find a working combination.  8)
Title: Re: MK-U47 - build thread
Post by: Energizer on December 31, 2015, 06:29:40 AM
Thank you for your replies, I'll try to swap the tubes and I'll keep you posted.
Happy New Year's Eve :-)
Brice
Title: Re: MK-U47 - build thread
Post by: gbruler on January 04, 2016, 06:11:11 AM
Hey everyone!  :D
A couple of days ago we have rented a real vintage U47 from a local studio, so we've done some tests. We had an important recording, and I've put both the vintage U47 and our MK-U48 in front of the singer.
Now I'm not really sure what's the condition of the Vintage U47, It looked and sounded really good, but it's the first time I use a real one. I'll leave the clips in here so you can judge for yourselves, but it seems like our MKU48 is really dark. We have nice Westren electric tubes from Christian Whitemore, and a beezneez capsule (I suspect that could be the issue). It seems like if you put a high cut on the Vintage U47, or a high shelf on the MKu48 it seems to be pretty close (didn't have time to really dig into it).
Here are the files (recorded through Sound skulptor's MP73 at exactly the same settings):
U47 - https://drive.google.com/open?id=0ByyLGJW4qi4eY2VQQXM1eU5ZVjA
MKU48 - https://drive.google.com/open?id=0ByyLGJW4qi4eS2VkSmdndW0wMjQ

So what do you guys think it is? is it the capsule or maybe something else is wrong?
I just want to add up that I have asked Ben from Beezneez about it, and he was willing to hear some clips, I sent him some clips almost 4 months ago and he didn't answer.

Thank you all for your help :)

Edit: Sorry if the links didn't work, they should work now!
Title: Re: MK-U47 - build thread
Post by: o3misha on January 04, 2016, 09:01:10 AM
For less low end and more bright sound you should use 60M grid resistor instead of 100M and 0.5 uF output coupling capacitor instead of 1uF. Also, you may try K67 style capsule.
Title: Re: MK-U47 - build thread
Post by: stelin on January 04, 2016, 07:11:04 PM
I don't think changing the grid resistor will help if you have a Beezneez capsule.
I have two Beesneez CK12 capsules and they both sound "dark" (or "warm", if you like the sound) on voices, since they have a rather big dip around 5-6 kHz (in the "ess" area).  The dips in my CK12s are about 10dB deep, and you can't fix that with a grid resistor change.
You can find clips on YouTube with Beesneez microphones. They all sound a bit dark (or warm). That's how Ben like to tune his capsules, I suppose.
I have Thiersch Red line capsules in my MK-U47s, and I have compared them to an original U-47 with a K49 capsule. You have to listen very hard with very good monitors to tell them apart.
If you are trying to contact Beesneez, send an email to Veronica instead: [email protected]

- Stefan
Title: Re: MK-U47 - build thread
Post by: Delta Sigma on January 05, 2016, 10:34:25 PM
...and a beezneez capsule (I suspect that could be the issue)...
I just want to add up that I have asked Ben from Beezneez about it, and he was willing to hear some clips, I sent him some clips almost 4 months ago and he didn't answer....

Which capsule? The K7 or M7? The K7 is supposedly an M7/K7 hybrid. Possibly a little darker than an actual K47. Their M7 I expect would definitely be darker. I'll also add to contact Veronica. I think they're a little busy right now though. I too have sent a message and not heard back.

...I have two Beesneez CK12 capsules and they both sound "dark" (or "warm", if you like the sound) on voices, since they have a rather big dip around 5-6 kHz (in the "ess" area).  The dips in my CK12s are about 10dB deep, and you can't fix that with a grid resistor change...

I have a Beesneez Arabella with a K7 capsule and a DIY U67 with a K6 and I don't find either to be darker than I expect. That being said, I don't have much to compare to. If there is a darkness or a dip in the high end, apparently I like it. I quite like both mics.
Title: Re: MK-U47 - build thread
Post by: gbruler on January 06, 2016, 01:09:49 PM
I guess I forgot to mention it's a K7 capsule.
Did you guys hear the clips? It's very noticable difference. It's not just a little darker. But again, when I raised the high end it sounded really close to the original U47, so yeah, it might be just how the capsule is tuned.
I will try Veronica's mail, see if it helps.
Anyway, if you do think it's the capsule, would you live with it and just use eq to raise the top end, or would investigate in maybe replacing the capsule?

Thanks again for your help :)
Title: Re: MK-U47 - build thread
Post by: stelin on January 06, 2016, 07:04:17 PM
I have heard the clips. The difference in sound between your clips is the same, relatively speaking, as it is in my MataChunger C12 when I compare the Beesneez CK12 to the Tim Campbell CT12. 
If you like the "Beesneeze sound" you could call it warm, smooth and rounded. If you don't like it you might say that it sounds like there is a blanket over the mic.
My humble opinion is that if you want your MK-U47 to sound more like the original U47, you should try a different capsule.
Title: Re: MK-U47 - build thread
Post by: Delta Sigma on January 12, 2016, 02:08:56 PM
@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/dwdl8htubzwbp3wos0ym)
https://app.box.com/s/50cp8xnfa601ih141xmj (https://app.box.com/s/50cp8xnfa601ih141xmj)

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

Did you follow proper Hi Z installation practices? Esp gloves and cleanliness when installing the capsule.
http://groupdiy.com/index.php?topic=58771.0 (http://groupdiy.com/index.php?topic=58771.0)

@stelin

I don't have much to compare to, but I wouldn't call the muffled sound in the above clip the "Beesneez sound".
Title: Re: MK-U47 - build thread
Post by: gbruler on January 14, 2016, 08:38:01 AM
@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/dwdl8htubzwbp3wos0ym)
https://app.box.com/s/50cp8xnfa601ih141xmj (https://app.box.com/s/50cp8xnfa601ih141xmj)

Here's the whole shootout:
http://studio939.blogspot.ca/2014/11/vocal-microphone-and-capsule-testing.html (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
Title: Re: MK-U47 - build thread
Post by: gbruler on March 08, 2016, 04:57:12 AM
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
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on March 08, 2016, 05:06:53 AM
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.
Title: Re: MK-U47 - build thread
Post by: DjaiTeam on March 08, 2016, 06:01:49 AM
At Gbruler, or your can ask Banzai. He sells them too and you can trust him.

http://groupdiy.com/index.php?topic=54169.0
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on March 08, 2016, 10:53:49 AM
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.
Title: Re: MK-U47 - build thread
Post by: DjaiTeam on March 08, 2016, 11:20:06 AM
Thats true but sometimes time is the gamebreaker when you want to finish something...
Title: Re: MK-U47 - build thread
Post by: Zander on March 17, 2016, 12:09:50 PM
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
Title: Re: MK-U47 - build thread
Post by: Pip on March 17, 2016, 07:54:40 PM
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.
Title: Re: MK-U47 - build thread
Post by: Zander on March 18, 2016, 04:02:43 AM
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
Title: Re: MK-U47 - build thread
Post by: Zander on March 18, 2016, 05:35:25 AM
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
Title: Re: MK-U47 - build thread
Post by: 59flame on March 18, 2016, 11:05:11 PM
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?
Title: Re: MK-U47 - build thread
Post by: Floti on March 20, 2016, 05:55:49 PM
I also could´t find the pictures and ended up following the diagram on the top of the 1st page.
Title: Re: MK-U47 - build thread
Post by: Pip on March 20, 2016, 07:20:09 PM
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.
Title: Re: MK-U47 - build thread
Post by: 59flame on April 15, 2016, 01:55:11 AM
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?
Title: Re: MK-U47 - build thread
Post by: 59flame on April 21, 2016, 08:49:51 PM
got it!
Title: Re: MK-U47 - build thread
Post by: 59flame on April 23, 2016, 01:07:40 AM
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?
Title: Re: MK-U47 - build thread
Post by: burglar on April 23, 2016, 06:44:58 PM
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.
Title: Re: MK-U47 - build thread
Post by: 59flame on April 24, 2016, 12:31:02 AM
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?
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on April 24, 2016, 03:36:34 AM
Why not just order a capsule mount directly from Beez?
Title: Re: MK-U47 - build thread
Post by: Category 5 on April 24, 2016, 10:22:06 AM
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. 
Title: Re: Neumann U47 Clone: MK-U47 Brass Housing & New Bv.08 Transformer
Post by: opacheco on April 29, 2016, 02:11:58 AM
One more quick rendering from my drawing, also showing the innards:
(http://www.twin-x.com/groupdiy/albums/userpics/Render3.jpg)

Hi ioaudio

do you have an AutoCAD drawing for this mic?

Opacheco.
Title: Re: MK-U47 - build thread
Post by: 59flame on May 25, 2016, 01:22:58 PM
I need the 3 screws for the head basket and the one screw that mounts the body to the bottom bell on the mku47.  Got lost somewhere in the shuffle/  anyone know what type of head and what size these  screws are? Max you out there?
Title: Re: MK-U47 - build thread
Post by: Citrus Hill on January 15, 2017, 05:56:13 PM
Hey Max,
I make a manual/build book for each project i build, and i was wondering if you could email me a BOM with the manufacturer/part number of the components you sent in your kits.  I purchased two kits from the original batch and i'm just now getting around to building them.  (Long story)  If it's not possible, i completely understand.  I've already pulled the values from the schematic, i'm just looking for the details on the specific components you chose for the build.  If anyone needs to repair the mics in the future, i want them to have the correct info to purchase the right replacement parts.
Thanks again for the nice kit!  I'm really looking forward to finally building these.
Thanks,
Citrus Hill

[email protected]
Title: Re: MK-U47 - build thread
Post by: gbruler on February 12, 2017, 10:06:16 AM
Hey guys,
Is it normal that the mic's PSU drops in voltage after around half an hour?
Lately we've heard some distortion out of the mic and we've noticed that when we bias the voltage to 105 it drops to 102-103. So now we've biased it to 107, and after 30 minutes it drops down to 105ish.
Thanks
Title: Re: MK-U47 - build thread
Post by: Delta Sigma on February 12, 2017, 11:34:31 AM
Are you biasing the mic after it's warmed up? Warm it up for an hour or two and set for 105 see if it drifts. 2V isn't much, I doubt it's causing your distortion. Can you describe the distortion? Is it always there or on transients?

Was it you that had trouble with a muffled sounding Beesneez capsule? Did you get that resolved?
Title: Re: MK-U47 - build thread
Post by: ChrioN on March 08, 2017, 08:10:23 PM
Ioaudio, if you see this, please send a PM or make yourself contactable  :)
Title: Re: MK-U47 - build thread
Post by: kosi on March 13, 2017, 04:23:29 PM
I'm selling a complete MKU47, if anyone should have interest !
https://groupdiy.com/index.php?topic=65455.0

already sold
Title: Re: MK-U47 - build thread
Post by: vineyardgray on March 16, 2017, 10:13:56 AM
I'm on vacation for March Break and thought I'd spend some free time finally getting this MK-U47 up and running.   Of course, now I see all the build pictures are missing!   :o

I don't suppose anyone made a file with Max's build post?

Regards,

Matt
Title: Re: MK-U47 - build thread
Post by: bancho on March 16, 2017, 06:37:38 PM
I'm on vacation for March Break and thought I'd spend some free time finally getting this MK-U47 up and running.   Of course, now I see all the build pictures are missing!   :o

I don't suppose anyone made a file with Max's build post?

Regards,

Matt

On the same boat here... let me know if you have any luck  :-\
Title: Re: MK-U47 - build thread
Post by: Delta Sigma on March 16, 2017, 11:02:16 PM
Strange, both Dany & Max's publicly shared dropbox files are suddenly dead links. I wonder if Dropbox changed their public link format.
Title: Re: MK-U47 - build thread
Post by: rainton on March 17, 2017, 02:38:24 AM
Strange, both Dany & Max's publicly shared dropbox files are suddenly dead links. I wonder if Dropbox changed their public link format.

Yes they did.

There's no public folder anymore.

The files are still there but Max and Dany will have to share them manually once more...
Title: Re: MK-U47 - build thread
Post by: vineyardgray on March 17, 2017, 10:56:54 AM
Some of the images are still interspersed throughout the thread - i will post them here for easy reference - one at a time so they stay on GDIY's servers.

Attached is the MK-U47 schematic.
Title: Re: MK-U47 - build thread
Post by: vineyardgray on March 17, 2017, 10:57:52 AM
Mk-U47 Wiring Diagram
Title: Re: MK-U47 - build thread
Post by: vineyardgray on March 17, 2017, 11:03:25 AM
Mk-U47 Tube Wiring Diagram
Title: Re: MK-U47 - build thread
Post by: Voodoobeat on April 18, 2017, 05:25:01 PM
On the same boat here... let me know if you have any luck  :-\

same here, wanted to start building and all the pictures are gone  :-\
has anybody by chance saved them?

Title: Re: MK-U47 - build thread
Post by: Voodoobeat on April 20, 2017, 06:47:33 PM
i wrote Max and he kindly sent me the pictures. So here you go

(http://voodoobeat.bplaced.net/MK-U47/MK-U47.jpg)
MK-U47 Tube Microphone Kit featuring:

Costum Headbasket made by Flea with Pattern Switch
Brass made body tube and bottom bell, bead-blasted and nickel-plated
Stainless internal structure
Bv.08 Transformer with 8 seperate sections from my own production
6028 single supply circuit with all parts including

(http://voodoobeat.bplaced.net/MK-U47/MK-U47-Kit.jpg)

including (back left to right):

body tube
bottom bell with power resistor mounted + internal structure
Headbasket pattern switch
Transformer + resistor board
High-Z board with screws, teflon isolators, shims for variable capsule mount height
solder lugs and subminiature reed-contact
Black rubber band for tube shock-mount
Tube deck + tube sockets, screws,


(front left to right):
Wiring, yellow wire sleeve, shrink tube
Binder connector for mic and cable
Bv.08 Transformer
PIO and styroflex capacitors, resistors

to complete the microphone, you'll need:
a capsule + holder
a single supply 105v PSU
a microphone cable (cable connector to mic included)

Completed kit with Flea capsule holder:
(http://voodoobeat.bplaced.net/MK-U47/PICT0125.JPG)


-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
BUILD:

Schematic:

(http://voodoobeat.bplaced.net/MK-U47/MK-U47_Schematic.GIF)

Wiring Plan:
(http://voodoobeat.bplaced.net/MK-U47/Mk-U47%20Wiring.jpg)

we start from the bottom up.

(http://voodoobeat.bplaced.net/MK-U47/20140619_174523.jpg)

Use small pieces of wire to bridge contacts as shown

(http://voodoobeat.bplaced.net/MK-U47/20140619_200816.jpg)

(http://voodoobeat.bplaced.net/MK-U47/20140619_200853.jpg)

wire the connector according to the original schematics
Solder a lug to the end of one black wire
1: White
2: Blue
3+4+6: Black x 2
5: Red

(http://voodoobeat.bplaced.net/MK-U47/20140619_204403.jpg)

Unscrew this resistor

(http://voodoobeat.bplaced.net/MK-U47/20140619_201707.jpg)

Solder yellow and red wire

(http://voodoobeat.bplaced.net/MK-U47/20140619_201935.jpg)

use shrink tube for isolation

(http://voodoobeat.bplaced.net/MK-U47/20140619_202039.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_202120.jpg)

mount the resistor back in

(http://voodoobeat.bplaced.net/MK-U47/20140619_202253.jpg)

unscrew the ring of the connector and place it
in the bottom bell, aligning the keyway/slot

(http://voodoobeat.bplaced.net/MK-U47/20140619_205327.jpg)

carefully place the ring and tighten

(http://voodoobeat.bplaced.net/MK-U47/20140619_205618.jpg)

unscrew the nut and place the solder luck and re-tighten

(http://voodoobeat.bplaced.net/MK-U47/20140619_205701.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_205747.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_205852.jpg)

paint the transformer/resistor board (not shown: use a file after breaking)

(http://voodoobeat.bplaced.net/MK-U47/20140619_210029.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_210450.jpg)

Solder together the boards as shown, check for right angle

(http://voodoobeat.bplaced.net/MK-U47/20140619_210601.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_210645.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_211701.jpg)

place and solder all resistors as shown

(http://voodoobeat.bplaced.net/MK-U47/20140619_211810.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_213220.jpg)

place and solder all wires as shown

(http://voodoobeat.bplaced.net/MK-U47/20140619_214842.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_215555.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_215607.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_215727.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_225335.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_230005.jpg)

Be careful handling the transformer
place and solder the transformer as shown

(http://voodoobeat.bplaced.net/MK-U47/20140619_230135.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_230235.jpg)


Before soldering the big capacitors it's time to mount the whole thing into the mic

(http://voodoobeat.bplaced.net/MK-U47/20140619_230758.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_230922.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_231252.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_231353.jpg)


insert the screws and attach the nuts, do not overtighten!

(http://voodoobeat.bplaced.net/MK-U47/20140619_231526.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_231638.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_231942.jpg)

Place and solder the two green capacitors as shown

(http://voodoobeat.bplaced.net/MK-U47/20140619_232206.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_232328.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_232409.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_232504.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_232901.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_233231.jpg)

The yellow sleeve will be cut like this to fir through the hole

(http://voodoobeat.bplaced.net/MK-U47/20140619_234456.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_234535.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140619_234601.jpg)

Carefully cut and drill (pierce) the rubber band as according to this measurements

(http://voodoobeat.bplaced.net/MK-U47/Rubber_Band.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_004633.jpg)

unscrew these parts

(http://voodoobeat.bplaced.net/MK-U47/20140620_004758.jpg)

mount the tube sockets, check for orientation!

(http://voodoobeat.bplaced.net/MK-U47/20140620_004911.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_012445.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_012525.jpg)

bend and add a solder lug

(http://voodoobeat.bplaced.net/MK-U47/20140620_014549.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_014645.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_014724.jpg)

attach and solder short black wire

(http://voodoobeat.bplaced.net/MK-U47/20140620_021444.jpg)

Wire up as shown

(http://voodoobeat.bplaced.net/MK-U47/Tube_wiring.jpg)

(http://voodoobeat.bplaced.net/MK-U47/20140620_022338.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_022358.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_022603.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_023256.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_024343.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_024458.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_024520.jpg)



attach the rubber band

(http://voodoobeat.bplaced.net/MK-U47/20140620_024752.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_025257.jpg)

mounting the tube deck

(http://voodoobeat.bplaced.net/MK-U47/20140620_025410.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_025459.jpg)

feed through the wire sleeve

(http://voodoobeat.bplaced.net/MK-U47/20140620_030422.jpg)

attach the yellow, red and blue wire to the corresponding pins

(http://voodoobeat.bplaced.net/MK-U47/20140620_031232.jpg)
(http://voodoobeat.bplaced.net/MK-U47/20140620_031514.jpg)

Be careful with overheating when building the highZ portion of the circuit

(http://voodoobeat.bplaced.net/MK-U47/20140620_031928.jpg)

bend and place the solder lugs as shown

(http://voodoobeat.bplaced.net/MK-U47/20140620_234527.jpg)
(http://voodoobeat.bplaced.net/MK-U47/PICT0072.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0073.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0074.JPG)


a small wire bridge, do not solder yet

(http://voodoobeat.bplaced.net/MK-U47/PICT0076.JPG)

the reed contact must be oriented and placed carefully BE VERY CAREFUL HERE

(http://voodoobeat.bplaced.net/MK-U47/PICT0077.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0078.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0079.JPG)

do not bend the contact after soldering or i will break



you can hold the tiny contact like this for placement

(http://voodoobeat.bplaced.net/MK-U47/PICT0080.JPG)

to have free access, slide the middle lug away

(http://voodoobeat.bplaced.net/MK-U47/PICT0081.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0082.JPG)

the contacts inside the glass envelope must be oriented this way

(http://voodoobeat.bplaced.net/MK-U47/PICT0083.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0084.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0085.JPG)

solder second side only after orientation is correct

(http://voodoobeat.bplaced.net/MK-U47/PICT0086.JPG)

more wire bridges and placing parts, place everything before soldering, solder quickly

(http://voodoobeat.bplaced.net/MK-U47/PICT0087.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0088.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0089.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0090.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0092.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0093.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0094.JPG)

the teflon feed throughs

(http://voodoobeat.bplaced.net/MK-U47/PICT0095.JPG)

push the carefully to place, grabbing them by the top teflon part

(http://voodoobeat.bplaced.net/MK-U47/PICT0096.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0097.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0098.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0099.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0100.JPG)

solder the two black wires

(http://voodoobeat.bplaced.net/MK-U47/PICT0101.JPG)

mount the highZ board + spacer as shown

(http://voodoobeat.bplaced.net/MK-U47/PICT0103.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0104.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0105.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0106.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0107.JPG)
(http://voodoobeat.bplaced.net/MK-U47/PICT0108.JPG)

attach the wires to the teflon feed throughs

(http://voodoobeat.bplaced.net/MK-U47/PICT0111.JPG)

attach the rest of the wires

(http://voodoobeat.bplaced.net/MK-U47/hiZ-wiring.jpg)

(http://voodoobeat.bplaced.net/MK-U47/PICT0113.JPG)

place the tubes

(http://voodoobeat.bplaced.net/MK-U47/PICT0117.JPG)

Shown with a Flea capsule holder

(http://voodoobeat.bplaced.net/MK-U47/PICT0125.JPG)
Title: Re: MK-U47 - build thread
Post by: DjaiTeam on May 01, 2017, 02:53:46 AM
Thanks for your effort putting this up gain Voodoobeat.
Title: Re: MK-U47 - build thread
Post by: Voodoobeat on May 22, 2017, 08:36:54 AM
i need a replacement for the 10nF Styroflex. i have this Koweg 10nF 160v cap, will it be good?
Title: Re: MK-U47 - build thread
Post by: vineyardgray on July 27, 2017, 10:27:56 PM
 :D

Thanks Voodoobeat for re-posting the pictures!  Much appreciated. 

I'd assume that your capacitor will be fine as they are both 10nf, but I couldn't say for sure about the voltage.
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 02, 2017, 11:42:29 PM
A  lot of the pictures just show up with little question marks - the recent reposted ones.

What happened to the original posts? I thought they would remain here at GDIY?
Title: Re: MK-U47 - build thread
Post by: djn111 on September 03, 2017, 06:32:53 AM
Hi,

No, only the text is on the server, all the pictures are on a outside hosting. So if you want or interested in a project always save it on your own computer :-). text can be done with print, and save it as a pdf, the pictures right click etc.

I always make a project map, and save al related, also data sheets etc.

DJN
Title: Re: MK-U47 - build thread
Post by: MatthiasAnton on September 09, 2017, 03:48:18 PM
Hi everyone!

I've searched the forum and google as best as I could but wasn't able to find any information as to how I could order a MK U47 kit, or if still at all possible, and at what cost? Can anyone provide some information or point me in the right direction? I saw the kit that is offered in Chunger's store but I'm much more interested in the point-to-point version with the pattern-change headbasket.

Thanks for your help, hope everyone is having a fantastic weekend so far!
Title: Re: MK-U47 - build thread
Post by: TillM on September 10, 2017, 04:07:19 PM
I wrote Max a email in July.
I never get an response.
So I think chunger is the only one who sells the Kits, except the u47.
Title: Re: MK-U47 - build thread
Post by: MatthiasAnton on September 12, 2017, 12:56:56 PM
That's too bad. I was afraid that would be the case when I saw that his whitemarket page was down :(
Hope the kits will come back some day...
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 14, 2017, 03:34:06 PM
It's strange because Max was such a huge contributor here, and presumably was doing well financially with his kits and products. I was very happy with the transformers I bought from him, and last I heard he was hard at work re-creating the famous M7 capsule.

I wonder if anything happened to him, and if he's OK. Anyone know?

Thanks
Title: Re: MK-U47 - build thread
Post by: djn111 on September 14, 2017, 04:36:37 PM
Hi,

Very busy on the other forum with his U67 recreation, he still post there.

DJN
Title: Re: MK-U47 - build thread
Post by: micaddict on September 14, 2017, 04:59:31 PM
Yup, he hit the jackpot with that one.
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 17, 2017, 09:19:43 PM
Hi,

Very busy on the other forum with his U67 recreation, he still post there.

DJN
Which forum?

Edit: nevermind. I found him on GS. I also sent him a PM asking him to reload the images for this build thread.
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 18, 2017, 05:36:38 PM
I got a response from Max. He thought the images were working fine in the repost, but I showed him that they are not all loading.

So he gave me this link to all the pictures for this project:

https://www.dropbox.com/sh/duo1tb100kekx4n/AAAUTcQcMqpIoVw6JCInVNRIa?dl=0 (https://www.dropbox.com/sh/duo1tb100kekx4n/AAAUTcQcMqpIoVw6JCInVNRIa?dl=0)

HTH,

Mike
Title: Re: MK-U47 - build thread
Post by: Voodoobeat on September 19, 2017, 11:19:06 AM
I can reupload them soon...
Title: Re: MK-U47 - build thread
Post by: Phrazemaster on September 19, 2017, 11:56:51 AM
I can reupload them soon...
Awesome!
Title: Re: MK-U47 - build thread
Post by: 59flame on February 28, 2018, 10:29:57 PM
can anyone who has one of maxs mku47 kits tell me if both the green Pi0  caps that came with it were 160v.  a 1uf 250 seems to big. want to return my mic to stock status and all i can find are 160v so i am thinking mine may have come with 160v can anyone confirm the voltage rating of the 1uf shipped with his original offerings? Thanks
Title: Re: MK-U47 - build thread
Post by: djn111 on March 01, 2018, 03:26:56 AM
Hi,

The power supply does not exceed 110V, so 160V should be fine (read the schematic).

DJN
Title: Re: MK-U47 - build thread
Post by: r2d2 on March 01, 2018, 12:21:04 PM
Hi All,

anybody have a zip,rar, etc.. about the docs(no more available) of first post in first page ?
thanks

ps: is this project open (alive) or closed ?
Title: Re: MK-U47 - build thread
Post by: Rixsta on March 01, 2018, 05:27:14 PM
Hey, I was just wondering is the t.bone SCT 700 https://www.thomann.de/gb/the_tbone_sct700_roehrenmikrofon.htm (https://www.thomann.de/gb/the_tbone_sct700_roehrenmikrofon.htm)
easy to mod into the U47 ?
Title: Re: MK-U47 - build thread
Post by: djn111 on March 01, 2018, 05:38:54 PM
Hi,

Doc's al the info is on page 33
https://groupdiy.com/index.php?topic=50694.msg833504#msg833504

Are you looking for specific info ?

A T-bone will never be a U47, but modification is not to be in this thread, this is about building a kit from IOaudio.

DJN
Title: Re: MK-U47 - build thread
Post by: TillM on March 02, 2018, 08:46:49 AM
ps: is this project open (alive) or closed ?

I think it's dead, Max has a lot to do with his U67 Mods for the U87 he sells on gearslutz.
Chunger had some kits in stock last year but they are all gone.
Your only chance is, that someone will sell his mic. So keep a look on the black market.
Title: Re: MK-U47 - build thread
Post by: r2d2 on March 03, 2018, 06:28:08 AM
I think it's dead, Max has a lot to do with his U67 Mods for the U87 he sells on gearslutz.
Chunger had some kits in stock last year but they are all gone.
Your only chance is, that someone will sell his mic. So keep a look on the black market.

Hi "TillM "  much thanks for info !

Ps:
http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Neumann-Mikro/U47/U47.htm
No Original VF 14 , No Original U47 / U67  Sound !!!
…and beware from tons of fakes vf14 around , overall on the web !
Title: Re: MK-U47 - build thread
Post by: [email protected] on March 17, 2018, 01:50:26 PM
Hi vinylwall,

Just curious why you chose to sell this kit? I had been looking at these, but they dont seem to be available. I have two different build projects unfinished, but these looked much simpler.

Thanks,
Title: Re: MK-U47 - build thread
Post by: vinylwall on March 18, 2018, 11:36:11 AM
Hi vinylwall,

Just curious why you chose to sell this kit? I had been looking at these, but they dont seem to be available. I have two different build projects unfinished, but these looked much simpler.

Thanks,

Well, I don't really want to sell it, but I have two of them and we are trying to raise some money for our wedding next fall.  So I've been listing some of my microphones on eBay.  I love this mic, but I need the money.  Thanks for asking.  Jimi Ray
Title: Re: MK-U47 - build thread
Post by: martthie_08 on March 12, 2019, 06:07:32 AM
I've taken liberty to resurrect the build information.
If this should disrupt anyones copyright please let me know and I will delete this post.

(http://www.martenthielges.com/diy/image/MK-U47/MK-U47.jpg)
MK-U47 Tube Microphone Kit featuring:

Costum Headbasket made by Flea with Pattern Switch
Brass made body tube and bottom bell, bead-blasted and nickel-plated
Stainless internal structure
Bv.08 Transformer with 8 seperate sections from my own production
6028 single supply circuit with all parts including

(http://www.martenthielges.com/diy/image/MK-U47/MK-U47-Kit.jpg)

including (back left to right):

body tube
bottom bell with power resistor mounted + internal structure
Headbasket pattern switch
Transformer + resistor board
High-Z board with screws, teflon isolators, shims for variable capsule mount height
solder lugs and subminiature reed-contact
Black rubber band for tube shock-mount
Tube deck + tube sockets, screws,


(front left to right):
Wiring, yellow wire sleeve, shrink tube
Binder connector for mic and cable
Bv.08 Transformer
PIO and styroflex capacitors, resistors

to complete the microphone, you'll need:
a capsule + holder
a single supply 105v PSU
a microphone cable (cable connector to mic included)

Completed kit with Flea capsule holder:
(http://www.martenthielges.com/diy/image/MK-U47/PICT0125.jpg)


-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
BUILD:

Schematic:

(http://www.martenthielges.com/diy/image/MK-U47/MK-U47_Schematic.GIF)

Wiring Plan:
(http://www.martenthielges.com/diy/image/MK-U47/Mk-U47%20Wiring.jpg)

we start from the bottom up.

(http://www.martenthielges.com/diy/image/MK-U47/20140619_174523.jpg)

Use small pieces of wire to bridge contacts as shown

(http://www.martenthielges.com/diy/image/MK-U47/20140619_200816.jpg)

(http://www.martenthielges.com/diy/image/MK-U47/20140619_200853.jpg)

wire the connector according to the original schematics
Solder a lug to the end of one black wire
1: White
2: Blue
3+4+6: Black x 2
5: Red

(http://www.martenthielges.com/diy/image/MK-U47/20140619_204403.jpg)

Unscrew this resistor

(http://www.martenthielges.com/diy/image/MK-U47/20140619_201707.jpg)

Solder yellow and red wire

(http://www.martenthielges.com/diy/image/MK-U47/20140619_201935.jpg)

use shrink tube for isolation

(http://www.martenthielges.com/diy/image/MK-U47/20140619_202039.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_202120.jpg)

mount the resistor back in

(http://www.martenthielges.com/diy/image/MK-U47/20140619_202253.jpg)

unscrew the ring of the connector and place it
in the bottom bell, aligning the keyway/slot

(http://www.martenthielges.com/diy/image/MK-U47/20140619_205327.jpg)

carefully place the ring and tighten

(http://www.martenthielges.com/diy/image/MK-U47/20140619_205618.jpg)

unscrew the nut and place the solder luck and re-tighten

(http://www.martenthielges.com/diy/image/MK-U47/20140619_205701.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_205747.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_205852.jpg)

paint the transformer/resistor board (not shown: use a file after breaking)

(http://www.martenthielges.com/diy/image/MK-U47/20140619_210029.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_210450.jpg)

Solder together the boards as shown, check for right angle

(http://www.martenthielges.com/diy/image/MK-U47/20140619_210601.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_210645.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_211701.jpg)

place and solder all resistors as shown

(http://www.martenthielges.com/diy/image/MK-U47/20140619_211810.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_213220.jpg)

place and solder all wires as shown

(http://www.martenthielges.com/diy/image/MK-U47/20140619_214842.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_215555.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_215607.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_215727.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_225335.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_230005.jpg)

Be careful handling the transformer
place and solder the transformer as shown

(http://www.martenthielges.com/diy/image/MK-U47/20140619_230135.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_230235.jpg)


Before soldering the big capacitors it's time to mount the whole thing into the mic

(http://www.martenthielges.com/diy/image/MK-U47/20140619_230758.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_230922.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_231252.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_231353.jpg)


insert the screws and attach the nuts, do not overtighten!

(http://www.martenthielges.com/diy/image/MK-U47/normal_20140619_231526.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/normal_20140619_231638.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/normal_20140619_231942.jpg)

Place and solder the two green capacitors as shown

(http://www.martenthielges.com/diy/image/MK-U47/normal_20140619_232206.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/normal_20140619_232328.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/normal_20140619_232409.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_232504.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_232901.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_233231.jpg)

The yellow sleeve will be cut like this to fir through the hole

(http://www.martenthielges.com/diy/image/MK-U47/20140619_234456.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_234535.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140619_234601.jpg)

Carefully cut and drill (pierce) the rubber band as according to this measurements

(http://www.martenthielges.com/diy/image/MK-U47/Rubber_Band.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_004633.jpg)

unscrew these parts

(http://www.martenthielges.com/diy/image/MK-U47/20140620_004758.jpg)

mount the tube sockets, check for orientation!

(http://www.martenthielges.com/diy/image/MK-U47/20140620_004911.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_012445.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_012525.jpg)

bend and add a solder lug

(http://www.martenthielges.com/diy/image/MK-U47/20140620_014549.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_014645.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_014724.jpg)

attach and solder short black wire

(http://www.martenthielges.com/diy/image/MK-U47/20140620_021444.jpg)

Wire up as shown

(http://www.martenthielges.com/diy/image/MK-U47/Tube_wiring.jpg)

(http://www.martenthielges.com/diy/image/MK-U47/20140620_022338.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_022358.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_022603.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_023256.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_024343.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_024458.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_024520.jpg)



attach the rubber band

(http://www.martenthielges.com/diy/image/MK-U47/20140620_024752.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_025257.jpg)

mounting the tube deck

(http://www.martenthielges.com/diy/image/MK-U47/20140620_025410.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_025459.jpg)

feed through the wire sleeve

(http://www.martenthielges.com/diy/image/MK-U47/20140620_030422.jpg)

attach the yellow, red and blue wire to the corresponding pins

(http://www.martenthielges.com/diy/image/MK-U47/20140620_031232.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/20140620_031514.jpg)

Be careful with overheating when building the highZ portion of the circuit

(http://www.martenthielges.com/diy/image/MK-U47/20140620_031928.jpg)

bend and place the solder lugs as shown

(http://www.martenthielges.com/diy/image/MK-U47/20140620_234527.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0072.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0073.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0074.jpg)


a small wire bridge, do not solder yet

(http://www.martenthielges.com/diy/image/MK-U47/PICT0076.jpg)

the reed contact must be oriented and placed carefully BE VERY CAREFUL HERE

(http://www.martenthielges.com/diy/image/MK-U47/PICT0077.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0078.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0079.jpg)

do not bend the contact after soldering or i will break



you can hold the tiny contact like this for placement

(http://www.martenthielges.com/diy/image/MK-U47/PICT0080.jpg)

to have free access, slide the middle lug away

(http://www.martenthielges.com/diy/image/MK-U47/PICT0081.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0082.jpg)

the contacts inside the glass envelope must be oriented this way

(http://www.martenthielges.com/diy/image/MK-U47/PICT0083.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0084.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0085.jpg)

solder second side only after orientation is correct

(http://www.martenthielges.com/diy/image/MK-U47/PICT0086.jpg)

more wire bridges and placing parts, place everything before soldering, solder quickly

(http://www.martenthielges.com/diy/image/MK-U47/PICT0087.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0088.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0089.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0090.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0092.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0093.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0094.jpg)

the teflon feed throughs

(http://www.martenthielges.com/diy/image/MK-U47/PICT0095.jpg)

push the carefully to place, grabbing them by the top teflon part

(http://www.martenthielges.com/diy/image/MK-U47/PICT0096.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0097.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0098.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0099.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0100.jpg)

solder the two black wires

(http://www.martenthielges.com/diy/image/MK-U47/PICT0101.jpg)

mount the highZ board + spacer as shown

(http://www.martenthielges.com/diy/image/MK-U47/PICT0103.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0104.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0105.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0106.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0107.jpg)
(http://www.martenthielges.com/diy/image/MK-U47/PICT0108.jpg)

attach the wires to the teflon feed throughs

(http://www.martenthielges.com/diy/image/MK-U47/PICT0111~0.jpg)

attach the rest of the wires

(http://www.martenthielges.com/diy/image/MK-U47/hiZ-wiring.jpg)

(http://www.martenthielges.com/diy/image/MK-U47/PICT0113~0.jpg)

place the tubes

(http://www.martenthielges.com/diy/image/MK-U47/PICT0117.jpg)

Shown with a Flea capsule holder

(http://www.martenthielges.com/diy/image/MK-U47/PICT0125.jpg)




Title: Re: MK-U47 - build thread
Post by: vinylwall on July 16, 2019, 09:55:50 AM
In case anyone is interested, I have a fully assembled iOAudio MK-U47 for sale:
https://www.ebay.com/itm/183894640663 (https://www.ebay.com/itm/183894640663)