UT Twin87
Twin-Circuit Condensor Microphone
7
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
6
Owner’s Manual
Version 1.0 as of 11/15/2021
Additional Support
Visit www.unitedstudiotech.com for additional
support.
Chapter 1: Now Let’s Get Started!
1.4 Mitigating “Real World” Problems
Chapter 1: Now Let’s Get Started!
1.3 Using the Vintage/Modern Modes
1.4
MITIGATING “REAL WORLD” PROBLEMS
While your UT Twin87 should
provide clean, trouble-free
operation in just about any
given situation; we’d like to
take a moment to go over
some real-world problems
we’ve encountered in our
combined years of experi-
ence, and how best to navi-
gate through them.
NOISE,
INTERFERENCE,
AND RADIO
Though rare, we’ve encoun-
tered this issue with other
microphones in the past.
Usually the result of operat-
ing near a radio broadcast
station or other large an-
tennae. Though sometimes
these situations cannot be
100% resolved; they can usu-
ally be reduced down to an
acceptable level by reducing
the amount of exposure the
signal path has to the source
of interference. This means
using the shortest length of
microphone cable possible,
avoiding the use of audio
snakes or in-wall connec-
tions; especially if unsure of
the length or quality of that
wiring. Sometimes re-posi-
tioning a mic or cable can be
of great benefit. Snake cables
(both in-wall and free-stand-
ing) with a shared foil shield
are the worst of all in this situ-
ation; as the foil shields on in-
dividual channels can branch
out to act as an antenna to
pick up signals from the air.
Not all microphone cables
are created equal; and if there
were ever a case for a very
well constructed microphone
cable with really low noise
and good CMR (common
mode rejection), this is one.
It’s also crucial to ensure the
mic cable has a proper and
dense enough shield, with
100% shield coverage, and is
terminated properly to pin 1
on both ends. While we don’t
recommend specific brands
here, some general advice is
that a braid shield will have
small gaps in the shield due
to the braid geometry which,
though usually OK, in highR-
FI (radio frequency interfer-
ence) environments, are not
ideal. A thick woven shield
is better, and a shield that is
coupled with a layer of foil
or conductive plastic is bet-
ter yet; ensuring total shield
protection. Double-shield-
ed microphone cable is the
best of all, for high-RFI envi-
ronments. BUZZ, HUM, AND
GROUND LOOPS Though
rare, microphones along with
all electronics can misbehave
when not properly grounded.
Like most phantom-powered
condenser microphones,
the UT Twin87’s XLR pin 1
grounds the microphone
chassis and circuit. This pin
mates to the pin 1 XLR input
of your preamp, console, or
recording interface, and from
there to the earth ground on
the IEC power connector for
that device. Things become
tricky if this device itself does
not have a 3-pin standard
IEC power cable, but instead
uses a 2 pin ‘wall-wart’ or
‘line-lump’ supply. In some
cases, you may have a small
interface which has no power
supply, relying on bus pow-
er from a computer’s USB,
firewire, or Thunderbolt con
-
nector. This situation is some-
times referred to as ‘vicarious
grounding’, where a ground
connection is passed through
several devices through vari-
ous analog and digital cables
before finally connecting to
the ‘house grounding’. Com-
puters, unfortunately, can be
a source of significant EMI
(electro-magnetic interfer-
ence). While these situations
cannot always be fully rem-
edied, especially with field
recording; at least being
aware of these potential is-
sues when setting up and se-
lecting equipment can spare
you from the worst of these
effects. For instance, if your
interface, laptop, preamp,
etc. all have no earth ground,
which is entirely possible with
laptop recording; you may
intentionally select a device
to connect in the chain that
the microphone can ground
to. An example of this would
be connecting an outboard
preamp or other processor to
the interface, so long as it has
a 3 pin IEC power cable that is
plugged in and an audio con-
nection such as XLR or TRS
that can connect to the in-
terface. This will ‘ground’ the
interface, even if the piece of
outboard gear is not being
used in the signal chain. Ad-
ditionally, well constructed
and shielded digital cables,
particularly with robust fer-
rite rings clamped on one or
both ends, can help reduce
any noise contamination
from a digital device into the
microphone. In any case, for
safety and good operation,
it cannot be recommended
that the UT Twin87 be operat-
ed in a situation where there
is no access to earth ground
to ground the microphone’s
pin 1 connector.
BUZZ, HUM, AND GROUND
LOOPS
Though rare, microphones
along with all electronics can
misbehave when not prop-
erly grounded. Like most
phantom-powered con-
denser microphones, the UT
Twin87’s XLR pin 1 grounds
the microphone chassis and
circuit. This pin mates to the
pin 1 XLR input of your pre-
amp, console, or recording in-
terface, and from there to the
1.3
USING THE VINTAGE/MODERN MODES
To protect the capsule and circuitry, the UT
Twin87 gently raises and lowers capsule polar-
ization voltages; therefore please allow about
ten seconds to fully stabilize when switching
to Modern or Vintage modes.
The Modern/Vintage switch allows selection
between the circuit design and sound of the
earliest version of the 87 style microphone
and the much later reproductions. This fea-
ture works by changing both the circuitry for
the high-Z and de-emphasis components, as
well as adjusting how the capsule is polarized.
In Vintage mode, the capsule is polarized di-
rectly with phantom power voltages (48v),
while in modern mode, an FET boost circuit
is employed to raise capsule polarization to
63v. The modern setting yields a slightly hot-
ter, brighter, more articulate sound, while the
vintage setting offers a slightly warmer, softer,
and smoother tone.
When Vintage/Modern modes are changed,
the UT Twin87
will require roughly 10 sec-
onds to morph between sounds
. This is nor-
mal in all operations, as the circuitry makes
significant configuration changes in order to
replicate both variations in extreme detail.
The modern setting yields a slightly hotter,
brighter, more articulate sound, while the vin-
tage setting offers a slightly warmer, softer,
and smoother tone.
