Product Overview

The Ultimate Balanced Destination for High-End Vinyl Playback

Turntable cartridges naturally produce a highly delicate, low-voltage electrical signal. In ordinary phono stages, this fragile signal is run through low-voltage op-amps, introducing color, phase distortion, and a high noise floor. The SPL Phonos duo changes everything by routing those sensitive currents through our proprietary high-voltage corridors.

The defining evolution of the Phonos duo is its dual-input, dual-output flexible framework. By implementing professional-grade, fully balanced XLR connection paths alongside gold-plated RCA terminals, the Phonos duo allows you to connect two separate tonearms or turntables simultaneously—toggling between an unbalanced deck and a fully balanced high-end system with a simple front-panel switch.

Product Description

120V VOLTAiR High-Voltage Headroom:

The musical authority of the Phonos duo is anchored by SPL's VOLTAiR technology. Operating on an internal plus/minus 60V DC power rail system—four times the electrical voltage found in traditional phono decks—the Phonos duo elevates maximum input capabilities to an unprecedented +32.5 dBu. This immense headroom ensures that sudden transient pops, dust clicks, or loud vinyl tracking peaks never push the internal electronics into harsh clipping or distortion. The music breathes in an open soundstage with incredible spatial separation and life-like rhythm.

Douglas Self RIAA Equalization Filter:

The critical RIAA equalization curve is executed through a precise analog filter built strictly around the legendary parameters of British audio specialist Douglas Self. By utilizing a network of premium, low-tolerance through-hole components, the Phonos duo achieves flawless frequency and phase linearity. It captures the absolute truth of the groove, delivering punchy bass lines, rich mid-tones, and beautifully transparent high frequencies.

Expanded Cartridge Tailoring Matrix (MM & MC):

The Phonos duo provides highly flexible, real-time matching parameters accessible right from the front panel:

• Moving Magnet (MM) Precision Tuning: Cable and systemic capacitance dramatically dictate the high-frequency response of MM systems. The Phonos duo expands its matching block to offer six selectable capacitance values: 12 pF, 47 pF, 100 pF, 150 pF, 220 pF, and 330 pF.

• Moving Coil (MC) Load Optimization: Since Moving Coil signals are incredibly faint (measured in microvolts), they require massive, ultra-quiet amplification. To perfectly flatten and align your MC tracking response, the front panel features six selectable impedance positions: 20 ohms, 50 ohms, 100 ohms, 220 ohms, 500 ohms, and 1000 ohms.

Comprehensive Level and Tool Integration:

To accommodate varying record pressings and system outputs, the Phonos duo includes a 3-way Gain switch:

• Low: Delivers +30 dB for MM / +50 dB for MC, ideal for standard consumer hi-fi lines.

• Med: Increases the signal block by 10 dB (+40 dB for MM / +60 dB for MC).

• High: Uncorks up to a massive +50 dB for MM and +70 dB for MC, level-matching your vinyl deck perfectly with modern high-output digital-to-analog converters.

• Mono, Mute, & Rumble Switches: Features a dedicated Mono switch to correctly sum and optimize the playback of vintage mono pressings, a Mute switch to safely silence lines during vinyl swaps, and a Subsonic Rumble filter to cut out low-frequency turntable drive vibrations.

Key Features

• 120V VOLTAiR CORE ENGINEERING: High-voltage DC operation yields unprecedented input headroom, low distortion, and an exceptionally quiet background noise floor.

• BALANCED AND UNBALANCED INS/OUTS: Features dual stereo inputs and outputs on professional balanced XLR and gold-plated RCA connectors.

• FRONT INPUT SELECTION SWITCH: Lets you switch instantly between the balanced XLR phono pair and the unbalanced RCA phono pair.

• PARALLEL LINE OUTPUTS: Decoded audio is always output simultaneously across both the XLR and RCA line outputs, regardless of which input is active.

• DOUGLAS SELF RIAA DESIGN: Premium discrete de-emphasis filter configuration reconstructs vinyl signals with absolute phase and frequency tracking.

• 6 MOVING MAGNET CAPACITANCES: Optimizes MM cartridges with ultra-precise selections: 12 pF, 47 pF, 100 pF, 150 pF, 220 pF, and 330 pF.

• 6 MOVING COIL IMPEDANCES: Fine-tunes MC loads on the fly through 20, 50, 100, 220, 500, and 1000 Ohm settings.

• 3-STAGE GAIN ADJUSTMENT: Tailors output levels up to a powerful +70 dB for low-output MC systems.

• DEDICATED MONO & MUTE TOGGLES: True mono summing switch for vintage records and a quick master output mute control.

• SUBSONIC RUMBLE FILTER: Safely rolls off harmful low-frequency driver mechanical rumble to protect your amplifiers and subwoofers.

• REAR GROUND LIFT SWITCH: Instantly isolates internal signal ground from the chassis ground to break up noisy electrical ground loops.

Technical Specifications

What’s Included in the Box

• 1 x SPL AUDIO Phonos duo Reference RIAA Phono Preamplifier Main Unit

• 1 x Standard AC Grounded IEC Power Cable

• 1 x Set of Premium Vibration-Isolating Chassis Feet

• 1 x Official SPL Professional Fidelity Series Phonos duo Operation and Alignment Manual