Description
Earthworks QTC40 is an omnidirectional
(pressure) prepolarized condenser microphone
directly coupled to a dedicated wideband, low
output impedance preamplifier. The QTC40
requires a standard 48V phantom power supply.
It features an extended linear free-field
frequency response from 4Hz to 40kHz (Fig. 2),
extremely fast impulse response (Fig. 3), low
self-noise, very low handling noise, uniform
polar pattern, and high SPL handling
capabilities. It exhibits no proximity effect.
Each microphone is delivered with its own
calibration chart providing the individually
measured frequency response curve. A
mounting clip is included with the microphone.
Applications
Earthworks QTC40 is easy to operate.
Connect the microphone to a microphone
preamplifier supplying 48V phantom power
using a standard XLR microphone cable. Please
allow up to one minute for the microphone to settle.
Plugging in the microphone “hot” (phantom
power already present at the input) will not
damage the microphone, and is actually
preferred for faster settling. It is normal for any
phantom powered mic to “pop” when plugged
in or powered up. Make sure to mute the signal
to speakers or headphones when phantom
power is first applied.
The QTC40 is designed for recording quieter
sources such as vocals, strings, woodwinds, and
distant-miked orchestras or choirs. For classical
location recording a matched pair will provide
spectacular results. It is ideal for quieter, more
detailed sources and does not have most of the
problems and limitations generally associated
with competitive microphones. Its impulse
response and diaphragm settling time is
exceptional, resulting in very natural and
uncolored sound.
This microphone has no removable parts.
Care of Microphones
Earthworks QTC40 microphone is a
precision instrument designed and built to
provide years of top performance. Following
these simple rules will help to protect your
investment in the QTC40:
• Avoid touching the front protective screen.
• Never attempt to disassemble the
microphone – it cannot be opened.
• Avoid extreme heat and condensing
humidity. Allow the microphone to warm up
in the case when bringing it in from the cold
weather. Rough handling may damage the
microphone even if no visible marks are left.
• When not in use keep the QTC40 in its case
Specifications
Frequency response: 4Hz to 40kHz ±1dB
Polar Pattern: Omnidirectional (Fig. 4)
Sensitivity: 30mV/Pa (Typical)
Power Requirements: 48V Phantom, 10mA
Peak Acoustic Input: 142dB SPL
Output: XLR (Fig. 1)
Output Impedance: 100Ω, balanced
(50Ωea. pin 2 & 3)
Minimum Load: 600Ωbtw. pins 2 & 3
Noise: 22dBA equivalent
Dimensions L x D 229 x 22 mm
(9 x .860 in.)
Weight: 225g (.5lb)
Compliant
Fig. 1. XLR Output Connector Assignment of QTC40
Fig. 2. Frequency Response (Typical) of QTC40
Fig. 3. Impulse Response (Typical) of QTC40
Fig. 4. Polar Response (Typical) of QTC40, 1dB/div.
Specifications are subject to change without
notice.
