REFERENCE 20

Reference 20 was created with a single goal: to transcend the limitations of established front-end architectures and redefine the possibilities of line-level performance.
Developed without any constraints, this product represents a complete rethinking of line-level preamplifiers. From mechanics and electrical systems to materials, every key element has been reconsidered, all in pursuit of one goal: absolute sonic transparency. The final result upholds Audio Research’s tradition, building upon the achievements of the previous SP-3 and Reference 1: it not only sets a new benchmark for Audio Research but also for the entire product category.
At the heart of Reference 20 is a completely new platform designed to eliminate sources of distortion previously considered unavoidable.
The traditional stamped chassis has been replaced by a sophisticated multi-layered metal structure designed to disperse and control resonant energy. Critical circuitry is mounted on a custom-designed suspended counterweight plate, further isolating the signal path and protecting it from mechanical influence.
This structural approach is not superficial, but fundamental. By optimizing the resonance at each level, Reference 20 preserves low-level information and spatial detail with unprecedented clarity and expressiveness.
The power supply section of Reference 20 has been completely redesigned to improve efficiency and reliability.
Through advanced voltage regulation technology and the application of the latest component technologies, including next-generation film capacitors, noise on the regulated rail is reduced by an order of magnitude. This significant reduction in noise floor allows the preamplifier to resolve the most subtle musical details while remaining stable amidst extreme dynamic range variations. Dynamic response and clarity are both top-notch, without sacrificing fullness or smoothness of sound.
The REF20 features a single-casing design that surpasses its powerful dual-casing predecessor in every aspect, even excelling in performance attributes typically associated with amplifiers: authority, impact, and resolution in extreme external environments of the recording space.
The final visuals are both more inspiring and more natural—effortless, fluid, and crystal clear.
The cumulative effect of these advances was not gradual, but transformative.
The Reference 20 surpasses previous reference-level designs in its musical layering, tonal integrity, timing consistency, and dynamic range. It not only conveys the structure of the recording but also reveals the performer’s intention and sense of presence.
In this way, it sets a new benchmark for the performance that a reference-level preamplifier can achieve.

Technical Specifications

Circuit Type: Dual-differential all-tube balanced circuitry
Tube Complement: (2) 6H30P dual triodes (signal gain), plus (1) 6550 and (1) 6H30P (power supply)
Frequency Response: 10 Hz to 40 kHz (-0.3dB at rated output); up to 120 kHz (-3dB)
Total Harmonic Distortion: < 0.03% at 2V RMS Balanced Output (10Hz-80kHz)
Gain: 12dB (Balanced output), 12dB (Single-Ended output)
Input Impedance: 25k ohms Balanced, 25k ohms Single-Ended
Output Impedance: 600 ohms Balanced, 375 ohms Single-Ended
Connectivity & Features
Inputs: 4 x Balanced XLR, 4 x Single-Ended RCA
Outputs: 3 x Balanced XLR, 3 x Single-Ended RCA
Subwoofer Out: Specially buffered to prevent impedance loading on main outputs
Optional Modules: Accommodates add-on DAC and phono preamplifier modules
Chassis: Machined aluminum-alloy with multi-metal layered construction and mass-loaded suspended boards to isolate resonant energy
Power Consumption: 60W maximum (100-135VAC or 200-250VAC)