Audio Research S-100 Stereo Power Amplifier

100 Wpc, Dual-Mono Construction, and Fully Balanced Circuitry in Audio Research’s Most Accessible S-Series Power Amplifier

The Audio Research S-100 brings the company’s latest solid-state amplifier platform to a more compact, lower-powered design. Rated at 100 Wpc into 8 ohms and 200 Wpc into 4 ohms, it combines substantial current capability with the engineering priorities Audio Research has developed through decades of both solid-state and tube amplifier design.

Like the larger S-200, the S-100 is a class-AB amplifier built on a dual-mono platform. Dual toroidal transformers support its ability to double rated output into 4 ohms, while the stereo circuit is fully balanced. Audio Research also specifies bipolar output transistors rather than MOSFETs, a choice the company attributes to their purity, transparency, and dynamic performance.

Modern S-Series Construction

The S-100 uses a machined aluminum chassis available in black or silver anodized finishes. Its industrial design retains recognizable Audio Research cues while taking a cleaner, more contemporary approach, including custom-machined heat sinks and no visible fasteners from the front or top.

Built and Evaluated in Minnesota

Audio Research describes the S-100 and S-200 as its latest and most advanced solid-state amplifier designs. Following measurement and bench testing, each amplifier is also evaluated by ear in keeping with the company’s longstanding development process. S-Series amplifiers are produced at Audio Research’s Minnesota facility alongside its Reference tube amplifiers.

Features

• 100 Wpc into 8 ohms and 200 Wpc into 4 ohms
• Class-AB operation
• Dual-mono architecture with dual toroidal transformers
• Fully balanced stereo circuit
• Bipolar transistor design
• Balanced and single-ended input capability
• Machined aluminum chassis
• Custom-machined heat sinks
• Black or silver anodized finish
• Made at Audio Research’s Minnesota facility

Specifications

Power Output: 100 Wpc into 8 ohms; 200 Wpc into 4 ohms

Total Harmonic Distortion (1 kHz, 8 Ohms): <0.1% from 0.25 W to rated output

Balanced Input Sensitivity: 1.4 V RMS for rated output

Input Impedance: 100 kΩ balanced or single-ended

Gain: 26 dB

Input Sensitivity: 1.8 V RMS for rated output

Noise: <60 µV output

Frequency Response: ±0.1 dB, 20 Hz–20 kHz

Power Requirements (120 VAC): 0.25 W standby; 48 W on at idle; 475 W at rated output

Dimensions (W × H × D): 19" × 7" × 17.5" (482.6 × 177.8 × 444.5 mm)

Shipping Weight: 63 lb. (28.5 kg)

Weight: 41 lb. (19 kg)