UT Twin87
Twin-Circuit Condensor Microphone
13
Owner’s Manual
Version 1.0 as of 11/15/2021
Additional Support
Visit www.unitedstudiotech.com for additional
support.
UT Twin87
Twin-Circuit Condensor Microphone
12
Owner’s Manual
Version 1.0 as of 11/15/2021
Additional Support
Visit www.unitedstudiotech.com for additional
support.
Chapter 2: About the UT Twin87
2.4 One more mod for good measure…
Chapter 2: About the UT Twin87
2.7 Making the Right Transformer
In our research into this design, we
learned of a certain modification
done to the circuit which ‘shorts’ the
mic into a permanent, cardioid-on-
ly mode by disabling the pattern
circuitry and decoupling the rear
diaphragm. This results in a slight
improvement in the signal-to-noise
ratio and output of the microphone,
and can be worth it for studios which
are wholly devoted to vocal produc-
tion and voice-over work, where the
other pattern options will simply
never be needed. After some exper-
imentation, we determined that we
could implement this mod into the
UT Twin87 without interfering with
the other two polar patterns. When
the UT Twin87 is set to cardioid, it
disables the rear diaphragm and pat-
tern circuitry, improving the signal by
simplifying the circuit path. Essential-
ly, the microphone becomes a more
simplified cardioid design. As with
the Modern/Vintage switch, it like-
wise takes a few moments to stabi-
lize when enabling and disabling the
pattern circuitry. This is just one more
under-the-hood mod for the enthusi-
ast, included free of charge.
We prototyped several transformers
during the development of the UT
Twin87, opting for a part that is some-
what larger than that found in most
specimens, with excellent band-
width, good shielding, and a mostly
neutral but just slightly softer/silkier
finish to it. Our UT Series transformer
matches the turns ratio, impedance,
and inductance of the earlier spec-
imens we measured; but is a design
of its own and delivers a very smooth,
polished sound.
Having determined that the lamina-
tion size and stacking of the trans-
former can have a restricting effect
on low frequencies, we made ours
somewhat larger than most found in
this type of circuit.
Our UT Series Twin87 transformers
are made to our exact specifications
in the US, and made from mostly US-
sourced raw materials .
While the UT Twin87 employs a new
headbasket design aimed at min-
imizing the sonic influence of the
microphone body on the sound, one
critical step we took was to identify
and locate the exact original mesh
gauges of the classic design. We have
recreated the 3 layer mesh makeup of
the original headbasket exactly: same
mesh gauges, laid down in the same
order. This ensures that, while the
overall effect of the headbasket-cap-
sule interaction has been reduced,
whatever filtering effect the headbas
-
ket had on the original microphone
has been exactly reproduced in terms
of sonic profile. This is one step often
overlooked on more budget con-
scious mic reproductions.
The UT Twin87 represents several
years of research and development,
to attempt to capture the essence of
not just one; but two of the most be-
loved condenser microphones, and
recreate them in a single package
for the modern recordist. We went
through several iterations of PCB de-
sign, mechanical designs, capsule de-
sign, transformer options, and so on.
We worked with the best microphone
circuit engineers, capsule engineers,
mechanical engineers, and trans-
former designers — ensuring every
step of the way that we maintained
direct and personal control over ev-
erything that went into our product.
It’s a common approach these days
to emphasize specific, critical compo
-
nents where a manufacturer placed
most of their investment and atten-
tion; and not to spend much time on
the rest of a circuit. From the onset,
we didn’t want this approach. Every
component in a design affects qual-
ity, and a chain is only as strong as its
weakest link. We looked at every re-
sistor, capacitor, transistor, connector
and switch. We labored over picking
the right thin film resistor here or
tantalum and polystyrene capacitor
there. Everything matters. This is our
approach to gear design.
The UT Twin87 uses our own repro-
duction of the classic K87 capsule
found in the earliest incarnations of
the ‘87 style microphone. Our capsule
is an insulated, dual backplate design,
skinned with 24k gold sputtered, 6 mi-
cron NOS PET film (Japanese Mylar).
The UT Series capsule is terminated
with a very fine-strand, silver-plated
teflon wire, and the microphone was
engineered so that the wire termina-
tions for the capsule are kept at the
shortest possible length. This, in con-
junction with very good insulation of
the capsule mount, reduces any in-
duced loss or interference to the low-
est possible levels.
2.4
ONE MORE MOD FOR GOOD MEASURE…
2.7
MAKING THE RIGHT TRANSFORMER
2.5
MESH MATERIAL
2.8
A HOLISTIC DESIGN APPROACH
2.6
THE UT SERIES CAPSULE AND IMPLEMENTATION
