Astatic CTM 77 User's Manual

CTM 77
Industrial Audio Products
ELECTRET CONDENSER CARDIOID
MICROPHONE
Description
The Astatic CTM 77 is a superior low-noise, electret condenser cardioid
microphone designed for professional vocalists and musicians. The CTM 77
provides the performance and features to satisfy today's most demanding
professionals.
The wide and flat frequency response of the CTM 77 provides natural transparent
sound quality. The cardioid pickup pattern minimizes annoying feedback (when
used close to sound reinforcement speakers and monitors) and reduces the pickup
of unwanted off-axis sounds. A transformerless electronic design provides optimum
low frequency response and low distortion. An effective internal multistage pop
filter minimizes wind and breath noise. The locking on/off switch provides excellent
flexibility of use.
The CTM 77 has a Flex-Form™ hardened steel grille screen that dramatically
resists deformation while greatly reducing any risk of adverse performance caused
by a bent or dented ball screen. This unique ability to retain its original shape
assures that the CTM 77 will maintain its attractive appearance.
The CTM 77 features the exclusive (I.N.R.-3™) Impact Noise Rejection system.
Our proprietary rubber shock mount isolates the transducer from the barrel, thus
dramatically reducing cable, stand and handling noise. The need for any external
shock mounting device is virtually eliminated.
The low-frequency response of the CTM 77 may be enhanced by increasing or
decreasing the distance from the sound source. This phenomenon is technically
known as “proximity effect”. Nominal or “flat” response is generated at a distance
of 24 inches or more. However, as the distance to the sound source decreases,
the bass sensitivity increases, providing a solid, robust character.
The CTM 77 is supplied complete with a zippered vinyl protective pouch and a
snap-in microphone swivel-mount.
CAD Quality
All Astatic CTM 77 microphones are audio tested and inspected prior to shipment.
Our absolute commitment to quality insures that Astatic microphones remain the
Best Value in today's competitive industry.
Operation and Maintenance
The Astatic CTM 77 is one of the finest instrumental and recording microphones
available. Although it is extremely durable, it should be stored in the zippered
pouch provided to protect it from dust and dirt when not in use.
If the front screen becomes soiled by dirt or residue, it may be cleaned using the
following procedure. Unscrew the front screen assembly and remove the inside
foam windscreen. Wash the foam windscreen using a mild detergent, and let dry
thoroughly. Follow the same method for the grille screen. To clean the mike
housing, use a cloth dampened with isopropyl alcohol.
Specifications
SPECIFICATIONS FOR CTM 77
Generating Element:
Electret condenser (Phantom Powered)
Polar Pattern:
Unidirectional (Cardioid)
Frequency Response:
50 Hz - 18 kHz
Output Level:
Open Circuit Voltage:
-55 dB (0 dB = 1 volt per microbar)
Impedance:
@ 1 kHz
500 ohms
Dynamic Range:
110 dB
Equivalent Noise Level:
Less than 22 dB, A weighted
Maximum SPL:
132 dB (1% THD, open circuit)
Powering:
Supply Voltage:
9 - 52 Vdc, positive pins 2 & 3 reverse polarity protected
Current Required:
Less than 5 mA over operating voltage range
Phasing
Positive pressure on diaphragm generates a positive voltage on pin 2
relative to pin 3
Grille Screen:
Hardened Steel Mesh
Case:
Steel and die cast zinc alloy
Finish:
Durable soft feel, non-slip, midnight black.
Dimensions:
(See drawing on other side)
Architects’ and Engineers’ Specification
The microphone shall be an electret condenser type, low impedance with
wide-range frequency response, uniform from 50 Hz to 18 kHz. Output
level at 1 kHz shall be -55 dB (0 dB = 1 volt per microbar). The polar
response shall show a minimum of -15 dB at 180 degrees between 300 Hz
and 1500 Hz. The transducer shall be isolated from handling noise and
other mechanically generated vibration. The microphone case shall be steel
and die-cast zinc alloy. The microphone shall have a length of 6 25/32"
and a maximum diameter of 1 13/16". The microphone body shall be
finished in a soft feel, non-slip midnight black. A snap-in clamp and a zippered
vinyl protective pouch shall be supplied.
The Astatic Model CTM 77 is specified.
TWO-YEAR LIMITED WARRANTY
Astatic Microphones are warrantied for two years to the original purchaser from the date of purchase by Omnitronics, LLC to be free
from defects in material and workmanship. In event of such defect, product will be repaired or replaced at Omnitronics, LLC discretion
with a new unit of equal or superior value. This will be at no charge if delivered prepaid to Omnitronics, LLC, together with the proof
of purchase and a Return Authorization Number. The unit will be returned promptly prepaid. Warranty excludes exterior finish,
appearance items, or malfunction due to abuse or operation under other than specified conditions. Consequential or incidental
damages are excluded. Serial number of product and original purchaser’s name must be registered immediately after purchase.
Please use the attached registration form for this purpose.
This warranty gives you specific legal rights and you may also have other rights which vary from state to state. Some states do not
allow the exclusion or limitation of incidental or consequential damages or limitations on how long an implied warranty lasts, so the
above exclusions and limitations may not apply to you.
Note: No other warranty, written or oral is authorized by Omnitronics, LLC.
SHIPPING INSTRUCTIONS
Please call our customer service department at 440-593-1111 for a pre-approved return authorization number and carefully repack
the unit and return it to: Omnitronics, LLC, 341 Harbor St., Conneaut, OH 44030
ALL RETURNS MUST HAVE A PRE-APPROVED RETURN AUTHORIZATION NUMBER OR IT WILL BE REFUSED.
If outside the United States, contact your dealer or distributor for warranty details.