ioaudio
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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
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:
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BUILD:
Schematic:
Wiring Plan:
we start from the bottom up.
Use small pieces of wire to bridge contacts as shown
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
Unscrew this resistor
Solder yellow and red wire
use shrink tube for isolation
mount the resistor back in
unscrew the ring of the connector and place it
in the bottom bell, aligning the keyway/slot
carefully place the ring and tighten
unscrew the nut and place the solder luck and re-tighten
paint the transformer/resistor board (not shown: use a file after breaking)
Solder together the boards as shown, check for right angle
place and solder all resistors as shown
place and solder all wires as shown
Be careful handling the transformer
place and solder the transformer as shown
Before soldering the big capacitors it's time to mount the whole thing into the mic
insert the screws and attach the nuts, do not overtighten!
Place and solder the two green capacitors as shown
The yellow sleeve will be cut like this to fir through the hole
Carefully cut and drill (pierce) the rubber band as according to this measurements
unscrew these parts
mount the tube sockets, check for orientation!
bend and add a solder lug
attach and solder short black wire
Wire up as shown
attach the rubber band
mounting the tube deck
feed through the wire sleeve
attach the yellow, red and blue wire to the corresponding pins
Be careful with overheating when building the highZ portion of the circuit
bend and place the solder lugs as shown
a small wire bridge, do not solder yet
the reed contact must be oriented and placed carefully BE VERY CAREFUL HERE
do not bend the contact after soldering or i will break
you can hold the tiny contact like this for placement
to have free access, slide the middle lug away
the contacts inside the glass envelope must be oriented this way
solder second side only after orientation is correct
more wire bridges and placing parts, place everything before soldering, solder quickly
the teflon feed throughs
push the carefully to place, grabbing them by the top teflon part
solder the two black wires
mount the highZ board + spacer as shown
attach the wires to the teflon feed throughs
attach the rest of the wires
place the tubes
Shown with a Flea capsule holder
