Audio Research PH9 Phono Stage

All-Tube Phono Preamplification With Five Selectable Cartridge Loads and Remote-Controlled Setup

The Audio Research PH9 brings the company’s long-running vacuum-tube approach to vinyl playback into a flexible, single-chassis phonostage designed to work with a broad range of cartridge and turntable combinations. Three 6H30 vacuum tubes form the core of its audio circuit, with additional tube regulation in the power supply.

With 58 dB of gain and five selectable impedance settings, the PH9 provides useful flexibility when matching a cartridge to the phonostage. Loading can be changed among 47k, 1,000, 500, 200, and 100 ohms, allowing you to experiment with cartridge loading without opening the chassis or changing components.

Cartridge Setup From the Listening Chair

The PH9’s loading settings can be changed on the fly using the included metal remote control. Its menu system also provides access to cartridge impedance, tube hours, auto shutdown, and other operating functions. A tube-hour meter makes it easy to keep track of operating time, while the display can be turned off when desired.

6H30 Vacuum-Tube Signal Path

Three high-current 6H30P dual triodes handle the audio signal, while a 6550WE and an additional 6H30P are used in the power supply. Electronically regulated low- and high-voltage supplies are complemented by an automatic two-minute warm-up and brown-out mute circuit.

The PH9 uses single-ended connectivity and provides a fixed 58 dB of gain. Its combination of adjustable loading, remote operation, and straightforward tube architecture makes it a particularly versatile Audio Research option for a vinyl-focused system.

Features

• Three 6H30P dual triodes in the audio circuit
• 58 dB fixed gain at 1 kHz
• Five selectable cartridge loads: 47k, 1,000, 500, 200, and 100 ohms
• Cartridge loading adjustable on the fly
• Remote-controlled operation and menu functions
• Tube-hour meter
• Auto-shutdown function
• Switchable display
• Electronically regulated low- and high-voltage power supplies
• 6550WE and 6H30P vacuum tubes used in the power supply
• Automatic two-minute warm-up and brown-out mute

Included Accessories

• Metal remote control

Specifications

Frequency Response: ±0.2 dB of RIAA, 5 Hz–20 kHz; 1 dB points below 0.3 Hz and above 80 kHz

Distortion (3 V RMS, 1 kHz Output): Less than 0.015%

Gain (1 kHz): 58 dB

Input Impedance: Selectable loads: 47k, 1,000, 500, 200, and 100 ohms

Output Impedance: 200 ohms; recommended load 50k–100k ohms and 100 pF; 10k ohms minimum and 2,000 pF maximum

Output Polarity: Non-inverting

Maximum Input (1 kHz): 80 mV RMS

Rated Output: 0.5 V RMS, 10 Hz–60 kHz, into 100k-ohm load; maximum balanced output capability is 0.46 V RMS at less than 0.5% THD at 1 kHz

Controls: 6 push buttons: Power, Menu, Option, Enter, Input, Mute

Power Supplies: Electronically regulated low- and high-voltage supplies; automatic two-minute warm-up/brown-out mute; line regulation better than 0.01%

Noise: 77 dB, shorted inputs

Tube Complement: 3 x 6H30P dual triodes; 1 x 6550WE and 1 x 6H30P in power supply

Power Requirements (US): 100–125 VAC, 60 Hz; 120 W maximum; 2 W standby

Dimensions (H × W × D): 6.5" x 19" x 13.7" (13.7 x 48 x 34.8 cm); handles extend 1.6" (4 cm) forward of the front panel

Shipping Weight: 23.5 lb. (10.7 kg)

Weight: 15.4 lb. (7 kg)