M100 MICROPHONE AMPLIFIER OPERATING AND MAINTENANCE MANUAL © Copyright 1997-2005, Audio Technologies Incorporated - Printed in USA Audio Technologies Inc. | 154 Cooper Road #902 | West Berlin, NJ 08091 | Voice 856-719-9900 | Fax 856-719-9903 | www. audio.
GENERAL The ULTIMIKE M100 Microphone Amplifier is designed specifically to provide the ultimate in no-compromise audio performance. A rugged, small AC line powered amplifier, it may be placed close to the mike on the stage, in the pulpit or in the overhead lighting structures to shorten sensitive low-level mike lines. Replacing your long runs of low-level mike cable with high level feeds will greatly reduce your susceptibility to RF, hash and hum pickup.
amplifier. When rack mounted, the level adjustment is accessible through the panel. A4A makes a switchable, unity gain high pass filter with two-pole response starting down (-3 db) at 150 Hz and rolling off 400 dB at 15 Hz. The filter is switched in or out of the circuit with S4. The output line driver A4B and output transformer T2 provide 16 dB of gain and the total isolation, faraday shielding, RF immunity and ease of use a true transformer coupled balanced output.
can make taking off the cover with the AC line still connected into a very exciting adventure. Different types of attachment plugs or line cords may be required for connection to alternate supply voltage. INSTALLATION MOUNTING The M100 can mount to any flat surface with the included angle brackets, which should be mounted to opposite small faces if the M100 by the cover screws. The M100 can be rack mounted either singly or in pairs in only1 ¾” using accessory Front Panel Kit, P/N20273-501.
NOTE Output transformers blocking RF and interrupting ground loops MUST be properly loaded in order to provide flat response and minimum overshoot. Always be sure that the output sees a 600 ohm load across pins 2 and 3. An occasional double load (300 ohms) is better than no load. REMOTE GAIN TRIM CONTROL A 10 Kohm linear potentiometer can be connected across a single conductor shielded cable with a standard RCA type phono plug at the M100 end.
readjustment. Audio Technologies Inc. | 154 Cooper Road #902 | West Berlin, NJ 08091 | Voice 856-719-9900 | Fax 856-719-9903 | www. audio.
COMMON MODE REJECTION Replacement of R6, R7, R8, R9, R62, C11, or C12 will require readjustment of R27 to maintain maximum common mode rejection (CMR). To set R27 apply 10 Vrms at 60 Hz between ground pin 1, pin 2, and pin 3 (tied together) of XLR input J1. Measure output (at J2 pins 2 to 3) and adjust R27 for null. A 90 dB CMR is attainable but may be difficult to measure without a turned voltmeter.
TECHNICAL SPECIFICATIONS GAIN 54 dB nominal, adjustable 0 to 74 dB. NOMINAL POWER -50 dBm / 150 ohms available input power +4 dBm / 600 ohms output. PEAK LEVELS -32 dBu in, +22 dBm out. MAXIMUM INPUT 0 dBu- HI gain switch, +20 dBu- LO gain switch NOISE OUTPUT -70 dBm, 20 to 20,000 Hz measurement bandwidth HUM OUTPUT -80 dBm, 60, 120, and 80 Hz. DYNAMIC RANGE 92 dB, peak output to noise. HARMONIC DISTORTION 20 to 20,000 Hz .10% THD maximum at peak level. .03% THD maximum at nominal level.
COMPRESSOR THRESHOLD +14 dBm out +/- 1 dB. COMPRESSOR SLOPE 4 : 1 maximum. COMPRESSOR TIMING 100 mSec attack and recovery. COMPRESSOR RANGE 20 dB gain reduction minimum REMOTE GAIN TRIMMER 10 kohm linear external pot, user supplied DC control, 0 to –15 dB range. PHANTOM POWER +48 VDC at 4 ma. through paralleled 6.8 Kohms resistors. AC POWER 115 – 230 VAC +/- 10%, 47 to 63 Hz, 4 VA. DIMENSIONS 1.5” H by 8.5” W by 5.5” D(9.75” W with mtg brackets); 3lbs. Net, 5lbs. Shipping weight.
