An all-tube Audio Research phono stage with moderate gain, switchable loading and the warm, lively sound that makes tubes and vinyl such a good match.
The PH9 is Audio Research's Foundation Series phono stage. Its signal path is short and simple: three 6H30P dual triodes handle all of the amplification. The power supply is tube-regulated too, using a 6550WE and another 6H30P. Gain is 58 dB, and you can set the cartridge load to 47 kΩ, 1,000, 500, 200 or 100 Ω from the front panel or the included metal remote. That means you can switch loads while the record plays and hear the difference right away. RIAA accuracy is within ±0.2 dB from 5 Hz to 20 kHz. The output stage is low-impedance (200 Ω), so the PH9 can drive long interconnects if your turntable sits across the room from your preamp.
Audio Research voices the PH9 to have tube warmth and life while staying neutral enough to show the real differences between cartridges and tonearms. At 58 dB of gain, it is a natural fit for moving-magnet cartridges and higher-output moving coils. It is a particularly good partner for the many excellent high-output MC and MM cartridges available today. If you run a low-output MC (roughly 0.3–0.5 mV), you will want more gain, from Audio Research's Reference phono stages or a step-up transformer. The PH9 suits a listener who wants a true tube phono stage at the heart of a serious vinyl system without moving up to Reference Series pricing and size.
| Type | All-tube MM/MC phono preamplifier |
| Gain | 58 dB at 1 kHz |
| Resistive loading | 47 kΩ, 1,000, 500, 200 or 100 Ω, selectable from front panel or remote |
| RIAA accuracy | ±0.2 dB, 5 Hz – 20 kHz |
| Maximum input | 80 mV RMS at 1 kHz |
| Noise | 77 dB (inputs shorted) |
| Outputs | Single-ended and balanced |
| Output impedance | 200 Ω (recommended load 50–100 kΩ) |
| Tubes | Three 6H30P in the audio stage; one 6550WE and one 6H30P in the power supply |
| Remote | Metal remote included |
| Power consumption | 120 W maximum (2 W standby) |
| Dimensions (W × D × H) | 19 × 13.7 × 6.5 in (handles add 1.6 in at front) |
| Weight | 15.4 lb (7 kg) |
A note from John: my first serious tube phono stage was an Audio Research PH3, back when I was just getting into vinyl with a Rega turntable. It turned an excellent analog front end into one that sounded truly alive, and it outplayed my far more expensive digital source. The PH9 follows the same idea: moderate gain, done extremely well, with the inner detail, presence and warmth that tubes bring to records.
Pearl Audio is an authorized Audio Research dealer. Call or visit our Portland showroom to talk about matching a phono stage to your cartridge.
