This headphone amplifier features 3 independent headphone outputs with individual level controls and balanced XLR inputs or 1/4" and 3.5mm stereo inputs.

The Marantz PHA-3 Stereo Field Production Headphone Amplifier provides three independent headphone feeds from balanced or unbalanced sources, and can drive headphones to high levels at audiophile quality with low distortion-ideal for field broadcast production companies, portable audio/video production crews, and live sound productions where critical audio monitoring is required, even under high SPL conditions. The PHA3 features a rugged metal case and the ability to daisy-chain additional units utilizing the Loop outputs.

3 Independent headphone outputs with individual level controls

Balanced XLR inputs or 1/4" and 3.5mm stereo inputs

Switchable stereo or mono operation

1/4" Loop output for daisy-chaining additional units in series for extra outputs

Parallel 3.5mm and 1/4" outputs with two additional 1/4" outputs

Internal power (2x AA) or external power (5-17VDC) with seamless switchover

GREEN LED indicates power with good battery, RED indicates low battery power

LED turns RED to warn when (4) hours of battery life remain

Rugged aluminum chassis with strap loops for wearing or mounting

Audio Specification:
Frequency Response: 10 Hz-50 kHz (± 1.0 dB)

Voltage Gain:
Balanced line input: Loop out -3dB, Headphone outputs 34dB
Unbalanced stereo input: Loop out -1dB, Headphone output 35dB
Output Clipping Level: +18 dBu minimum with 600? load, +16 dBu minimum with 300? load
Input Clipping Level: Line input (XLR) +24dB

Impedance:
Headphone output 200?
Loop out 200?
Line input (XLR) 22 k?
Stereo/Loop in (1/4" / 6.35mm) 9.1k?
Stereo/Loop in (1/8" / 3.5mm) 9.1k?
Dynamic Range: > 120 dB
Total Harmonic Distortion (THD) +N: 0.03% max (10 Hz-22 kHz @ +10 dBu input/output level, 300? load)

Inputs / Outputs:
(2) XLR inputs, electronically balanced
(1) 1/4" (6.35mm) TRS line input, unbalanced
(1) 1/8" (3.5mm) TRS line input, unbalanced
(3) 1/4" (6.35mm) TRS headphone outputs
(1) 1/4" (6.35mm) TRS line output , unbalanced

General:
Internal Voltage Rails:± 15V regulated
Power adapter: 5-17 VDC, center-positive coaxial connector (5.5mm outer diameter, 2.1mm inner diameter)
Power adapter input voltage: 110-120 VAC, 60Hz / 220-240 VAC, 50Hz
Batteries: 2x AA alkaline batteries (battery life approx. 12 hrs / one set of 75? headphones driven, 8hrs / one set of 56? headphones driven
Dimensions: 3.7 x 5.6 x 1.7" (94 x 140 x 43mm)
Weight: 1.2 lbs / 0.6 kg