Preamplifiers — PS Audio Stellar Phono Preamplifier

The Stellar Phono Preamplifier is a solid-state phono stage from PS Audio, part of its Stellar line and designed by Darren Myers. It stays analogue from input to output and is built as a fully discrete FET circuit that avoids integrated circuits anywhere in the signal path. PS Audio states it is designed and assembled in the US, and the case is available in silver or in black. The first product the company made, back in 1975, was also a phono preamplifier.

Key specs that matter

Gain for MM is switchable between 44, 50 and 56 dB, and moving coil gain between 60, 66 and 72 dB. The 70 dB ultra low noise setting supports cartridges with outputs as low as 0.15 mV. MM loading is 47 kohm with 100 pF, while MC loading can be set to 60, 100, 200 or 47k ohm, or to a custom value between 1 ohm and 1 kohm through rear-panel potentiometers. Frequency response is 20 Hz to 20 kHz within 0.25 dB, and THD is below 0.01 percent at 0.5 V and 1 kHz. With A-weighting, noise is more than 82 dB down for MM and 74 dB down for MC. Maximum output is 24 V RMS at 1 percent THD, overload margin is above 22 dB at 1 kHz, and interchannel crosstalk is better than 74 dB.

Engineering and use context

Parallel Toshiba JFETs make up the input side and MOSFET devices the output side, with both running in Class A bias. The circuit is DC coupled with a short signal path. RIAA equalisation is passive, using film and foil capacitors from the Reliable range of Wilson Audio, internal feedback is kept low, and ultra low noise discrete regulation stages sit before and after the voltage supply. Components are hand-selected. An oversized high current power transformer feeds the circuit, and internal shielding supports the low noise of the MC gain stages. The case is 430 mm wide and 330 mm deep, the unit weighs 9.8 kg, it draws 26 W at idle, and the output mutes automatically at switch-on.

Pairing

Two RCA phono inputs accept two tonearms or two turntables, each able to take a moving coil or moving magnet cartridge, and the remote switches between them. Output is available on an RCA pair and on a balanced XLR pair, both with an output impedance below 200 ohm, so the stage can feed a line input of either type. The remote handles power, muting, gain, MM or MC selection and loading, and a rear master switch sits beside a detachable IEC mains inlet.

Alternatives

The PS Audio PMG Signature Phono Preamplifier is the other phono stage in the current range of the maker.