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Headphone output – Studio Technologies 212 2006 User Manual

Page 11

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Model 212 User Guide

Issue 3, July 2006

Studio Technologies, Inc.

Page 11

or be an independent handheld or stand-
mounted model. The Model 212’s 48 volt
nominal power source will support essen-
tially all phantom-powered microphones.
The quality of the Model 212’s microphone
preamplifier and associated circuitry is such
that special applications may benefit from
using “high-end” microphones. If selected
appropriately, models from manufactur-
ers such as AKG, Beyer, DPA, Neumann,
Sennheiser, and Shure will perform very
well in Model 212 applications.

Microphone interconnection is made by
way of a 3-pin female XLR-type connector
which is located on the Model 212’s back
panel. The mating connector (male) should
be wired so that pin 2 is signal high (+ or
hot), pin 3 is signal low (– or cold), and pin
1 is shield. It’s possible that an unbalanced
microphone will also work correctly. In this
case, the mating connector (male) should
be wired so that pin 2 is signal high (+ or
hot), and signal common/shield is connect-
ed to both pins 1 and 3.

The Model 212 is not compatible with
unbalanced “electret”-type microphones
that require a source of low-voltage DC for
operation. These microphones, sometimes
found in low-cost headsets, are not gener-
ally suitable for on-air or other demanding
applications.

As of the writing date of this user guide, the
Sennheiser HMD25 headset is very popular
for on-air sports broadcasting use. A fine
product, it works very well with the Model
212. Note that adding the suffix “-XQ” to the
headset’s part number (HMD25-XQ) speci-
fies a 3-pin male XLR-type connector for the
dynamic microphone and a ¼-inch 3-con-
ductor plug for the stereo headphones. This
configuration is very useful, allowing the
headset to work directly “out of the box”
with the Model 212.

If the writer may digress for a moment to
recount a story… an audio dealer once
shared a secret with me concerning head-
sets. He loved selling the “lower-end” (less
expensive) models of name-brand head-
sets, which he did by the veritable “boat-
load.” Why? Because these usually broke
soon after going into service! He knew
that on a regular basis he’d receive orders
for more of them. Had these users, from
the beginning, purchased only premium-
quality headsets, their total cost of owner-
ship would have been much less. Enough
said…

Headphone Output

The Model 212’s headphone output is
compatible with stereo or mono head-
phones, headsets, or earpieces. Connect-
ing devices with a nominal impedance
of 100 ohms or greater is preferred. This
shouldn’t prove to be an issue as essen-
tially all contemporary devices already
meet this condition.

Devices are connected to the headphone
output by way of a ¼-inch 3-conductor
phone jack located on the Model 212’s
back panel. As is standard for stereo
headphones, the left channel is connected
to the “tip” lead of the ¼-inch headphone
jack. The right channel is connected to the
“ring” lead of the jack. Common for both
channels is connected to the “sleeve”
lead.

Devices with ¼-inch 2-conductor “mono”
plugs can also be used with the Model
212’s headphone output. In this arrange-
ment only the tip lead (left channel) will
be active. The 2-conductor plug will physi-
cally connect (“short”) the ring lead (right
channel) to the sleeve lead (common).
Technically this won’t damage the cir-
cuitry associated with the right-channel