Sony SCD-C555ES SACD changer Sony TA-P9000ES preamp

Sidebar 2: Sony TA-P9000ES multichannel analog preamplifier

Sony describes the $700 TA-P9000ES as "a pure audio multichannel preamplifier equipped with two inputs for 5.1 analog multichannel audio sources, enabling selection, volume control, and amplification." A relay with twin gold-plated crossbars switches the two six-channel sources. Then follows a class-A solid-state push-pull amplifier in discrete configuration. Separate transistors, resistors, and capacitors populate the printed circuit boards. An oxygen-free copper shield surrounds each channel to prevent crosstalk between the channels. In addition, there is a relay-controlled gain stage offering 0, +6, and +12dB amplification.

The P9000 can be operated with its remote, which signals microprocessor-controlled motors used for the volume, input, and output relays. Once the microprocessors have finished the switching, their clock is stopped to render them completely silent to avoid sonic degradation. Further attention to detail can be found in the use of a linear-wrap-core power transformer, said to have very low magnetic distortion and magnetic loss. The volume control features a strong steel housing and a newly improved resistive membrane claimed to have a minimum of "resonance modulation."

Sony rates the TA-P9000ES's harmonic distortion at less than 0.003%, 20Hz-20kHz at 1V, A-weighted; the frequency response at 10Hz-100kHz, +0/-1.0dB; the S/N ratio at 115dB (20kHz LPF, A-weighted at 1.3V input level); the input sensitivity at 150mV; and the input impedance at 20k ohms.

Moving from left to right, the front-panel controls include a power switch, a rotary selection switch, and a series of rotary controls to balance the gain of the front-channel speakers, subwoofer, center channel, and each surround. There's also a gain-level switch that increases the gain of the other channels relative to the gain of the front channels. The master volume control sits at the right edge of the front panel and can be controlled by a remote.

Around back are a series of multichannel (six input jacks) subpanels for those inputs (Input 1 and Input 2) whose volume will be controlled by the TA-P2000ES, and subpanels labeled "Bypass 5.1ch" and "Bypass 2ch," which appropriately bypass all front-panel controls. There's also a subpanel for the Control A1 jack used to switch a companion amplifier on and off.

The TA-P9000ES's fit'n'finish are tops—I loved it. These switching and control functions are rarely found on preamplifiers three times the price.—Larry Greenhill

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