Усилители мощности моно — Cary Audio SA-500.1 ES

The SA-500.1 ES is a transistor mono power amplifier by Cary Audio, announced in April 2018 at USD 4,995 and built at the company's factory in Raleigh, North Carolina. It succeeds the original SA-500.1, a clean-sheet design that marked a departure from Cary's traditional valve work. Cary describes the ES version as essentially a bridged SA-200.2 ES, so one chassis delivers the combined output of both channels of the stereo model into a single speaker.

Key specs that matter

Working in Class AB, the output stage produces 500 W into 8 ohm and 1,000 W into 4 ohm, both specified across 20 Hz to 20 kHz. Frequency response runs from 10 Hz to 50 kHz within ±0.1 dB. Voltage gain is 28 dB and input impedance is 30 kOhm on both the XLR and the RCA input. Signal to noise ratio is above 100 dB A-weighted, total harmonic distortion stays below 0.05% at rated output, and the damping factor exceeds 400 from 10 Hz to 400 Hz. A remote trigger input accepts 3.3 to 24 V DC at 5 mA or more. Every chassis is 197 mm tall, 450 mm wide and 495 mm deep, weighs 29.5 kg and has a matte black powder-coated case whose front panel is silver or black aluminium.

Engineering and use context

An 850 VA low-noise toroidal transformer, custom-wound with separate windings for the regulated input board, feeds more than 98,000 uF of storage capacitance. Those capacitors sit on the amplifier boards next to the circuitry, and extra bypass capacitors are placed right at the output devices, with several smaller parts used instead of a few large cans to keep ESR low. Sixteen 150 W bipolar output transistors share the load on a newly designed heat sink with a larger radiating surface, and heat dissipation is up to 50% higher than in the earlier model. The input stage is a monolithic device on its own heat sink for temperature stability and low offset. The circuitry is spread over four field-replaceable fibreglass boards. Protection covers temperature and DC offset through a high-current relay, without conventional voltage or current limiting. Cary quotes 3 dB of dynamic headroom and 100 hours of break-in.

Pairing

High current capability and stability into low impedance loads let a pair of these drive difficult or low-sensitivity loudspeakers, and a balanced preamplifier can feed the XLR socket. Cary intends it for both music and home cinema systems.

Alternatives

The Cary Audio CAD-211FE is the brand's valve monoblock, using 845 output triodes for up to 150 W in Class B.