One of the very best phone stages ever made, IMHO. Almost unlimited settings for impedance, noise free, dynamic and neutral, and a unique high frequency contour to allow high impedance loading but eliminate ultrasonic ringing. In perfect working condition, as far as I can tell. Extremely rare on the used market.
This one is in the optional black anodize and black wood side rails. Unit comes with the acrylic cover as well as the metal cover, owners manual, box and PC cord.
From their website: The Model 7PX3 Phono Preamplifier s designed for the person seeking the ultimate in phono reproduction. A complete stand-alone phono preamplifier with an external power supply, it can be used with a line level preamplifier, a digital preamplifier with an analog line level input, or a passive switchbox controller. Like that of our other audio components, the sonic character of the 7PX3 emphasizes musical naturalness rather than the overly dramatic “high fi” sound with exaggerated definition and consequent fatiguing high-frequency reproduction. The exceptional neutrality of the 7PX3 enables it to mate equally well with either vacuum tube or solid state preamplifiers.
Consistent with our commitment to a musically natural sound, all signal amplification is accomplished with our discrete proprietary circuits potted in modules labeled Music Module™. While we hold technical excellence in the highest regard, our final choice in circuits and components for the Music Module™ is based on their ability to accurately reproduce the correct tonal and harmonic character of music itself. Furthermore, each Music Module™ is constructed and adjusted for its particular function in the circuit.
All critical passive parts in the 7PX3 (jacks, wire, resistors, etc.) have been selected on the basis of extensive listening evaluation in our own reference system and are chosen primarily for their ability to yield the most transparently natural sound at all frequencies. (Some of the parts are extremely expensive aerospace components rarely used in consumer grade equipment.)
• RIAA Equalization is passive using the very finest parts available.
• The external power supply uses a toroidal transformer with a capacity approximately 5 times the actual preamp power consumption. It provides filtered dual-polarity DC power to the main chassis via a shielded power cord and a premium-quality screw-lock connector.
• Internal power-supply regulation is accomplished with three precision cascaded levels. The first level provides ripple and line transient filtering, and locks to a nominal DC level. The second and third levels use individual precision feedback regulators for each channel which independently feed the first and second amplification stages via “star” networks. This trilevel regulation system, consisting of a total of ten independent regulators, provides a very high level of channel separation.
• Main outputs are direct coupled to eliminate the need for large blocking capacitors in the signal path. DC offset is maintained to plus or minus three millivolts with DC servo circuits operating outside the signal path. All inputs and outputs are protected with shunting diodes.
Gain: Adjustable at 36, 50, 64, or 66dB at 1 KHz.
RIAA accuracy: +/- 0.2 dB at 1.0 VRMS out.
Bandwidth: 0.5Hz. to 150KHz.
Input impedance: Resistance is adjustable from 100 to 47K Ohms. (User selected resistors allow any value between 0 and 47K Ohms.) Capacitance is fixed at 150pF.
Output impedance: 300 Ohms, both main and tape outputs.
Finish: The Chassis is finished with a black Polyurethane paint with a light texture. The Face Panel is anodized, in either black or platinum gold. The Side Bars are black lacquered Ash with a semigloss finish.
Dimensions: The 7PX3 is 2.5 inches (6.4 cm.) high, 19 inches (48.3 cm.) wide, and 11.58 inches (29.4 cm.) deep.
Weight: The preamplifier weighs approximately 12 pounds. The power supply weighs 3 pounds, and total shipping weight is approximately 20 pounds. Actual shipping costs to be borne by buyer.