120B Distribution Amp

Servo balanced audio distribution amplifier

High Quality Audio Distribution Amp

  • 1 input/4 output with output trim adjustments
  • Transformerless design for wide, flat frequency response
  • Works for audio or time code

Transformerless High Performance Audio Distribution

Model 120B is a high performance audio distribution amplifier with a single high impedance input and four low impedance outputs, all electronically servo-balanced and designed to be as transparent as possible. The 120's transformerless circuits are designed for wide, flat frequency response, free from ringing or overshoot, making it ideal for distribution of time code or audio. Each output has its own amplifier and level control for maximum versatility and isolation. The sturdy steel chassis may be used stand-alone or rackmounted, singly or in pairs.

Input

The input circuit is adjusted for optimal common-mode rejection. Servo-balancing compensates for high common-mode voltages, so headroom isn't sacrificed. The high input impedance allows bridging of the input signal with minimum loading. This way several amplifiers can be easily driven from the source.

Outputs

The individual output amplifiers are very low impedance so long lines and capacitive loads are easily driven with no loss of stability or high frequency response. Servo-balancing permits the outputs to be used single-ended at any time without a change in gain by simply grounding the unused pin. Individual output level controls are recessed for bump-proof operation, yet can be easily adjusted without tools. The front panel power LED also acts as a signal present and clip indicator for the input.

Rackmount Kit for 120B, 124B and 141B
Allows for the rack mounting of one or two "B" series products in one rack space. The new front panel design of the "B" series products and the new rack mount kit design makes installation 100% faster!

Part # 45-008B
NOTE: This kit is ONLY for "B" series units. Contact Aphex for info about rack mounting kits for legacy products.

Audio

Frequency Response 5Hz - 100 kHz (+0, -0.5dB)
Dynamic Range 94 dB
Hum and Noise Better than -90 dBm at unity gain
THD 0.002% @ +4dBm, 0.005% @ +20dBm
IMD 0.002% @ +10dBm
Channel Isolation 70dB
Slew Rate 13 V/usec

Input

Connector XLR 3-pin Female
Type Transformerless, differential servo balanced
Impedance 100k ohms balanced
Maximum Level +25 dBm
CMRR (typical) > 45 dB

Output

Connector XLR 3-pin Male
Impedance 65 ohms
Maximum Level +25dBm into 600 ohms balanced, +21dBm unbalanced
Output Gain Range ±15 dB

Other Specifications

Power Requirements 100, 120, 220, OR 240 VAC, 50-60Hz
Dimensions 1.75"H x 8.25"W x 7.25" D (44.5mm x 209.5mm x 184.2mm)
Net Weight 3.5 lbs (1.6 kg)

All specifications are subject to change without notice.

Owner's Manual