ATI Audio AMM200 - Manual (Page 2)

ATI Audio Inc. Tel: 856-719-9900 [email protected] www. audio.com
DESCRIPTION
The AMM200 Analog Audio Preamplifier, Meter and Monitor is a full-featured stereo
line amplifier and monitor with balanced/unbalanced bridging XLR line inputs and
amplified servo-balanced/unbalanced line outputs plus stereo headphone drivers and a
stereo LED meter. The bright two-color LED meter is switchable to measure either the
line input or line output levels. Ballistics are selectable for either peak or average meter
response. The meter covers a wide dynamic range of –15 to +12dB in ten 3dB steps.
Switched rear panel RCA jacks allow external self-powered speakers to be controlled
from the headphone drivers.
The AMM200 can be used free-standing, desk mounted or rack mounted up to three
across in one rack unit (1-3/4”). Optional field cases, protection plates and battery power
packs are available (see Field Accessories).
PERFORMANCE
The AMM200 provides dynamic range in excess of 114dB and THD below 0.1%
measured at the analog line and headphone outputs for all levels below clipping. All
measurements are noise limited at –90dB EIN (20Hz to 20kHz bandwidth). Frequency
response is +0 / -.25dB, 20Hz to 20kHz.
LINE INPUTS
The AMM200 accepts balanced or unbalanced stereo audio signals from XLR female
connectors. Nominal input levels at –20dBu (.07Vrms), -10dBu (.25Vrms) or +4dBu
(1.23Vrms) can be selected by moving internal jumper plug J9 to the desired position.
20Kohm balanced instrumentation amplifier inputs accept input levels up to +22dBu.
Higher inputs result in clean clipping with no phase reversal.
LINE OUTPUTS
Analog line level outputs for balanced or unbalanced audio lines of 600 ohms or greater
impedance are available on rear XLR type connectors. Ground sensing output drivers
(U7, U8) allow either the HI or LO output lines to be grounded for connection to
unbalanced loads. Grounding one side of an output pair shuts off drive to the grounded
line and doubles the output signal on the ungrounded side, thus maintaining normal
circuit operation and gain. Front panel trimpots set the nominal line output level to
+4dBu (1.25V) at 0dB on the line output meter, which allows 18dB headroom up to the
peak output level of +22dBu. Up to 43dB of gain is available from line input to output.
Frequency response is flat within .25dB from 20Hz to 20kHz and THD is well below
0.1% over the same frequency range at any output level below clipping. Output noise is
below –90dBu at unity gain.