Audio Research is one of the most dependable brand names when it comes to high-end audio systems. For years the brand has been recognized by audiophiles throughout the world as equipment that delivers clear and consistent quality in music.

What are the specs for the Audio Research D125?

Power Output:
110 watts per channel minimum continuous power (both channels operating) at 16 ohms from 20Hz to 20kHz with less than .4% total harmonic distortion (typically below .005% at 1 watt) Approximate actual power available per channel at "clipping" (both ch. op., 1kHz): 115 Watts. (Note that the actual power output is dependent upon both line voltage and "condition" ie: if power line has high distortion, maximum power will be affected adversely, although from a listening standpoint this is not very critical.)
Power Bandwidth:
(-3 dB points) 10 Hz to 80kHz
Frequency Response:
Input Sensitivity:
0.7V RMS for rated outputs
Input Impedance:
100K ohms, nominal
Output Taps:
4, 8 and 16 ohms
Output Regulation:
Approximately 0.4 dB, 16 ohm load to open circuit
Overall Negative Feedback:
21 dB
Damping Factor:
Approximately 20
Less than 0.4% total harmonic distortion at 110 watts (typically below .005% at 1 watt)
Slew Rate:
20 V/µs
Rise Time:
3 µs
Hum & Noise:
90 dB below rated output - less than 2mV RMS - (Broad-bandwidth unweighted, inputs muted)
Power Supply Energy Storage:
Approximately 280 joules
Power Requirements:
105-125VAC 60Hz (210-250VAC 50Hz) 1000 watts maximum, 400 watts at "idle".
Tube Complement:
(4 matched pairs) 6550
19" (48 cm) W (standard rack panel) x 8 ¾" (22.2 cm) H x 16½" (42 cm) D (front panel back). Handles extend 1 ⅝" (4.1 cm) forward of the front panel.
84 lbs. (38 kg) Net, 95 lbs. (45.5 kg) Shipping

What else to know about the Audio Research D125?

Features include: Servo for auto balance of plate currents between output tube push & pull pairs; Front panel LED indicators and adjustment controls for left and right channel output tube plate current; Low current LED indicator for each output tube viewable through cover; "Tube Saver" circuit to protect output tubes from abnormal conditions or input overloads (eg. DC); Twin subsonic cooling fans for temperature control and increased life of output tubes.

Brief History of Audio Research

Other Audio Research Products We Often Buy

Typically, StereoBuyers purchases mostly used amplifiers, especially the vintage amps and high-end Audio Research models.

StereoBuyers has purchased tens of thousands worth Audio Research brand equipment since 2014, with individual buys ranging from $100 to well over $50,000. If you are moving, ready to upgrade, or have Audio Research equipment you do not or will not be using, why not contact us today to find out if it is worth good money?

If you are interested in selling your used Audio Research equipment to us in the greater NYC area or Colorado, please click here to fill out a Free Quote Form and we will get back to you. If we agree on terms, we come to meet you where you want, and pay cash.

The following images show actual Audio Research equipment purchased by StereoBuyers.