Усилители мощности стерео — Parasound JC5

The Parasound JC5 is a stereo power amplifier designed by John Curl, built around high-bias Class A/AB circuitry that holds the first 12 W of each channel's output in pure Class A. Parasound calls it a high-power, high-current amplifier. Parasound lists it at USD 7,000 with a 3-year parts and labor warranty, and the chassis comes in either black or silver. Shipping weight is 40.8 kg.

Key specs that matter

With both channels loaded, output is 400 W per channel into 8 ohms and 600 W into 4 ohms, measured at 120 VAC and 0.05% THD from 20 Hz to 20 kHz. Bridged into 8 ohms it delivers 1,200 W as a mono amplifier. Peak current reaches 90 A, and Parasound states stability with speaker impedance dips down to 1.5 ohms. THD is below 0.05% at full power and below 0.03% at typical levels, IM distortion is under 0.04%, and TIM is unmeasurable. Signal-to-noise ratio exceeds 116 dB A-weighted and 111 dB unweighted. Crosstalk is above 87 dB at 1 kHz and 72 dB at 20 kHz. Frequency response runs from 5 Hz to 100 kHz at plus 0 and minus 3 dB, and from 20 Hz to 20 kHz within 0.25 dB. Slew rate exceeds 130 V per microsecond, with damping factor at 1000 at 20 Hz.

Engineering and use context

The JC5 uses dual-mono construction, in which every channel gets a supply of its own, fed by a 1.7 kVA shielded toroidal transformer and 132,000 uF of Rubycon filter capacitors. Input circuits are discrete and balanced, and no capacitors or inductors sit between input and output. Input impedance is 33 kilohm unbalanced or 66 kilohm balanced. A 1 V input, balanced per leg or unbalanced, gives 28.28 V at the output, for a total gain of 29 dB. The case measures 448 mm wide, 181 mm tall without feet or 197 mm with them, and 508 mm deep, or 546 mm with cables. Net weight is 33.1 kg. Power consumption is 1 W in standby, 225 W at idle, 400 W during typical listening and up to 1,500 W. Rack-mount hardware is included in the box, so the amplifier can go straight into an equipment rack.

Pairing

Neutrik locking XLR inputs and Vampire gold-plated RCA jacks accept either balanced or single-ended preamplifiers. The amplifier switches on from a DC trigger of 9 to 12 V at 5 mA or from an audio signal of 2 to 10 mV. Speaker cables connect to CHK Infinium custom 5-way binding posts.

Alternatives

The Parasound NC 2250v2 is a two-channel NewClassic model rated at 275 W per channel into 8 ohms.