Интегральные усилители — Cary Audio SLI-100

The SLI-100 is a stereo valve integrated amplifier made by Cary Audio in North Carolina, introduced in October 2018 at USD 5,995. Cary describes it as the more powerful sibling of the SLI-80HS, and the step up comes mainly from a quartet of KT150 output valves in place of the smaller KT88 types. The circuit is hand-wired and runs as a push-pull ultra-linear design in Class AB1.

Key specs that matter

Rated output is 100 W per channel. The valve complement is two 6922 input buffers, two 6SN7 pre-drivers that double as phase inverters, and four KT150 power valves. Sensitivity for full output is 0.45 V, input impedance is 100,000 ohm and maximum gain reaches 34 dB. Cary gives a response of 19 Hz to 23 kHz within ±0.5 dB at full power, with noise and hum 82 dB below rated output. Four pairs of RCA line inputs are fitted, plus an RCA subwoofer output, and a 6.35 mm jack serves headphones. Operating draw is 166 W, falling to 83 W in standby. The chassis is 198 mm high, 438 mm wide and 406 mm deep and weighs 19 kg, and the matte black case takes knobs and a front panel in either silver or black aluminium.

Engineering and use context

Bias for the KT150s comes from a negative fixed bias supply rather than cathode resistors. The first stage is a Series Regulated Push-Pull circuit working in Class A, and the 6SN7 phase splitter is a self-balancing split-load type. Only 4 dB of overall feedback is applied, taken from an output transformer tap, and signal polarity is non-inverting. Cary stresses the custom output transformers as the key part of the design, while the mains side uses an EI laminate power transformer rated for a 200% duty cycle. A removable cage covers the valves. Cary lists a warm-up of roughly three minutes once switched on and around 100 hours of use before a new unit settles.

Pairing

Separate 4 and 8 ohm secondary taps, chosen by toggle switches beside the five-way binding posts, let the owner match the output transformer to the nominal load of the loudspeaker. The line-level subwoofer output makes it simple to add a powered bass unit, and the headphone jack covers private listening without a separate amplifier. Sources such as a CD player, DAC or streamer connect directly to the RCA inputs, while a turntable needs an outboard phono stage because none is built in.

Alternatives

The Cary Audio SLI-80HS is the lower-powered valve integrated in the same family, using KT88 output valves with switchable triode and ultra-linear modes.