For nearly 50 years, the brand Audio Research has been renowned worldwide for its preamplifiers and phono stages. Indeed, Audio Research has been making preamplifiers with phono inputs since the early 70’s and separated RIAA stages since 1992, and this even during vinyl’s difficult years.
Recently, the manufacturer from Minneapolis released the Reference 3 phono preamplifier, which is considered to be one of the best phono preamplifiers on the market.
Like with every Audio Research product, the PH9 phono preamplifier is meticulously hand-crafted and tested and auditioned before being packaged.
AUDIO RESEARCH PH9: FRONT AND BACK PANEL
The front panel has a green LED display indicating the load, Mono or Stereo, and an hour meter to keep you aware of how many hours are on the tubes.
All functions are accessible via a remote control or via the 6 buttons under the display on the front panel.
The back panel has RCA inputs and outputs. Its low output impedance means that the PH9 can be used with relatively long cables, and this, with a lossless signal transmission.
AUDIO RESEARCH PH9: CIRCUIT
The Audio Research PH9 phono preamplifier has some of the same innovations as the Reference 3. However, the circuit is simpler and more “economical”.
When the cover is taken off, you can see the magnificent “made in USA” circuit! The RIAA equalizer has three high current 6H30 tubes. This enables the PH9 phono preamplifier to provide excellent dynamics and a better sound.
The audio signal follows a simple and clear path. The components of this circuit are of the highest quality in order to obtain the most transparency possible.
A high power R-core transformer and 8 filter capacitors make up the power supply.
Just like in the Phono Reference 3, the PH9 has vacuum tube regulation (one 6550 + one 6H30).
This Audio Research PH9 has a fixed gain of 58 dB and a loading option of 100, 200, 500, 1000 and 47k ohms which can be chosen using the front panel or remote control.
AUDIO RESEARCH PH9: COMPATIBILITY
The PH9 is a superb phono stage with a remarkable musicality. However, the fixed gain is a little too low for some MC cartridges and too high to add an MC step-up transformer (this is the only thing that we regret).
I will not even talk about MM cartridges which are not even a debate on a phono preamplifier of this range. Be careful not to use cartridges that have an output voltage inferior to 0.3 mV.
AUDIO RESEARCH PH9: TESTING AND LISTENING
From the opening bars, we were seduced and surprised by the realism and presence of the voices. The transparency and definition linked with an unparalleled timbre quality completely transport the listener in the recording studio.
The sound is remarkably balanced and homogeneous.
The beauty of the timbre and the natural sound restitution make us play one vinyl record after another without even being frustrated or asking ourselves questions. The PH9 makes the music even more beautiful with more emotions than its competitors, without adding colour or changing the spectral balance.
The bass deserves a special award! It has depth and is perfectly controlled, whether it is on a double bass, an organ, or a synth.
Regarding the quality and the neutrality of the timbre, the Audio Research PH9 phono preamp is one of the current best phono preamplifiers. Highly recommended!
Hi-Fi News - Outstanding Product - 2016
Frequency response: 5 Hz to 20 kHz at 1 dB, 0.3 Hz and more than 80 kHz
RIAA accuracy: ± 0,2 dB
Gain: 58 dB at 1 kHz
Signal-to-noise ratio: > 77 dB
Distortion: < 0,015% at 3 V RMS 1 kHz output
Selectable loads: 47k, 1000, 500, 200, 100 Ohms
Audio tubes: 3 x 6H30
Power supply tubes: 1 x 6550WE and 1 x 6H30
Dimensions: 48 x 13.7 x 34,8 cm + 4 cm for the handles
Weight: 7 kg