Audio Research PH9 Vacuum Tube Phono Preamplifier

High-End Tube Phono Stage • Three 6H30 Vacuum Tubes • 58dB Gain • Five Selectable Cartridge Loads • Tube-Regulated Power Supply • Remote-Controlled Cartridge Loading

Complimentary White Glove Delivery • Private Consultations • Travel Reimbursement Available*

The Audio Research PH9 is a high-performance vacuum tube phono preamplifier engineered to extract exceptional resolution, dynamic range and tonal accuracy from vinyl records. Combining a three-tube 6H30 analog amplification circuit, 58dB of gain, five selectable cartridge loading settings and a vacuum tube-regulated power supply, the PH9 delivers the transparency and musical authority that define Audio Research analog electronics.

Designed for serious turntable systems, the PH9 accommodates a broad range of moving coil and compatible moving magnet cartridges. Its adjustable input impedance allows precise cartridge matching, while remote-controlled loading makes it possible to evaluate different settings without interrupting playback.

With RIAA equalization accuracy of ±0.2dB from 5Hz to 20kHz, distortion below 0.015% and a wideband circuit extending beyond 80kHz, the PH9 is engineered to preserve the information captured in the record groove.

Three 6H30 Vacuum Tubes

The PH9's analog signal path uses three 6H30P dual-triode vacuum tubes, selected for their high transconductance, current capability and linear performance.

Audio Research's circuit design emphasizes a direct signal path, low distortion and precise RIAA equalization. The 6H30 architecture provides the gain necessary for low-output phono cartridges while preserving transient detail, harmonic structure and low-level musical information.

The result is a tube phono stage capable of reproducing the full character of a recording, from delicate acoustic passages to complex orchestral dynamics.

Five Selectable Cartridge Loading Settings

Proper cartridge loading is essential to achieving accurate frequency response, tonal balance and transient performance from a moving coil cartridge.

The Audio Research PH9 provides five selectable input impedance settings:

• 100 ohms

• 200 ohms

• 500 ohms

• 1,000 ohms

• 47,000 ohms

Settings can be changed directly from the front panel or with the included aluminum remote control, even while a record is playing.

This flexibility allows the PH9 to accommodate cartridges with different electrical characteristics and provides a practical method for optimizing cartridge performance within a complete analog system.

Vacuum Tube-Regulated Power Supply

The PH9 incorporates an electronically regulated power supply featuring a 6550WE power tube and an additional 6H30P tube.

A high-current transformer and substantial power supply reserves support stable operating conditions for the sensitive phono amplification circuitry.

Separate regulation of low- and high-voltage supplies minimizes fluctuations that could compromise signal accuracy. Automatic two-minute warm-up and brownout muting protect the system during startup and power interruptions.

The regulated design contributes to the PH9's low-noise performance, dynamic authority and controlled bass reproduction.

Precision RIAA Equalization

Accurate RIAA equalization is fundamental to faithful vinyl playback.

The PH9 maintains ±0.2dB accuracy from 5Hz to 20kHz, with its wideband response extending below 0.3Hz and above 80kHz at the specified 1dB points.

This precision preserves the intended frequency balance of recorded music while minimizing deviations that can alter tonal accuracy.

With a specified distortion level below 0.015% at 3V RMS output, the PH9 is designed to maintain clarity and separation throughout complex recordings.

Remote Control and Tube Monitoring

The PH9 combines traditional vacuum tube engineering with practical system control.

Its front-panel display and supplied metal remote provide access to cartridge loading, input selection, muting and configuration functions.

An integrated tube-hour meter tracks operating time to assist with maintenance and tube replacement planning. Automatic shutdown and display-off functions provide additional convenience for dedicated listening rooms.

Technical Specifications

Specification	Details
Brand	Audio Research
Model	PH9
Product Type	Vacuum Tube Phono Preamplifier
Circuit Architecture	All-Tube Analog Amplification
Signal Path Tubes	3 × 6H30P Dual Triodes
Power Supply Tubes	1 × 6550WE, 1 × 6H30P
Phono Gain	58dB at 1kHz
Cartridge Loading	100Ω, 200Ω, 500Ω, 1,000Ω, 47kΩ
Cartridge Compatibility	Moving Coil and Compatible Moving Magnet
Analog Input	Single-Ended RCA
Analog Output	Single-Ended RCA
RIAA Equalization Accuracy	±0.2dB, 5Hz–20kHz
Extended Frequency Response	-1dB Points Below 0.3Hz and Above 80kHz
Total Harmonic Distortion	Less Than 0.015% at 3V RMS, 1kHz
Noise	Greater Than 77dB, Shorted Inputs
Input Impedance	User Selectable
Output Impedance	200Ω
Recommended Output Load	50kΩ–100kΩ, 100pF
Minimum Output Load	10kΩ
Maximum Recommended Load Capacitance	2,000pF
Output Polarity	Non-Inverting
Maximum Input	80mV RMS at 1kHz
Rated Output	0.5V RMS
Power Supply	Electronically Regulated High- and Low-Voltage
Power Supply Line Regulation	Better Than 0.01%
Warm-Up Protection	Automatic 2-Minute Mute
Front-Panel Controls	Power, Menu, Option, Enter, Input, Mute
Remote Control	Included Metal Remote
Tube Monitoring	Integrated Tube-Hour Meter
Power Requirements	100–125V AC, 60Hz
Maximum Power Consumption	120W
Standby Power Consumption	2W
Width	19" / 48cm
Height	6.5" / 16.5cm
Depth	13.7" / 34.8cm
Handle Projection	1.6" / 4cm
Net Weight	15.4 lb / 7kg
Shipping Weight	23.5 lb / 10.7kg

Audio Research PH9 at The Grid HiFi

Reference Analog System Design

The Grid HiFi is Houston's destination for high-end turntables, reference phono preamplifiers, vacuum tube electronics and complete analog audio systems.

The Audio Research PH9 is designed for discerning vinyl listeners who demand precise cartridge matching, low-noise amplification and accurate reproduction of their record collections.

Our team provides comprehensive analog system engineering, including:

• Turntable and Tonearm Matching: Selecting compatible analog playback components.

• Phono Cartridge Optimization: Moving coil cartridge selection, loading and gain compatibility.

• Reference Preamplifier Integration: Matching the PH9 with Audio Research line stages and other premium amplification.

• Analog Cable Selection: Low-capacitance phono interconnects, grounding and signal management.

• Turntable Isolation and Setup: Mechanical isolation, cartridge alignment and playback optimization.

• Complete System Installation: Professional configuration and commissioning of reference vinyl systems.

The PH9 integrates naturally into sophisticated systems built around Audio Research Reference preamplifiers, vacuum tube power amplifiers and high-resolution loudspeakers.

Private Consultation and White Glove Service

Complimentary White Glove Delivery • Travel Reimbursement Available*

Qualifying purchasers may receive airfare reimbursement for a private audition when completing an eligible purchase.

Considering the Audio Research PH9? Let The Grid HiFi engineer your complete analog playback system. Call (713) 218-8120 to arrange a private consultation.

*Restrictions apply. Contact The Grid HiFi for eligibility and details.

Frequently Asked Questions

Does the Audio Research PH9 support moving coil cartridges?

Yes. The PH9 provides 58dB of gain and selectable loading at 100, 200, 500, 1,000 and 47,000 ohms. These settings accommodate many moving coil cartridges. Compatibility should be confirmed against the cartridge's output voltage and recommended loading.

Can the PH9 be used with moving magnet cartridges?

The PH9 can be used with compatible moving magnet cartridges, but its fixed 58dB gain is higher than that of many conventional moving magnet phono stages. Cartridge output voltage and system gain must be considered to avoid overload.

Can cartridge loading be adjusted during playback?

Yes. The PH9 allows cartridge loading adjustments through the front panel or supplied remote control while a record is playing.

Does the Audio Research PH9 have balanced XLR connections?

No. The PH9 uses single-ended RCA inputs and outputs. It is designed to connect to a line-level preamplifier or integrated amplifier.

How many vacuum tubes does the Audio Research PH9 use?

The PH9 uses five vacuum tubes in total: three 6H30P tubes in the audio circuit, plus one 6550WE and one additional 6H30P in the regulated power supply.

Where can I purchase an Audio Research PH9 in Houston?

The Grid HiFi in Houston, Texas, provides Audio Research product consultation, cartridge matching, complete analog system design and professional setup. Call (713) 218-8120 for assistance.