Усилители мощности стерео — Orchard Audio Starkrimson Stereo Ultra 2.5

The Starkrimson Stereo Ultra 2.5 is a GaN Class D stereo power amplifier from Orchard Audio, the American maker from Succasunna, New Jersey, where Leo Ayzenshtat leads the design work, and it is priced at USD 3,249.95 with free US shipping. Revision 2.5 builds on Revision 2.0 by adding a built-in active RCA-to-XLR converter, so the amplifier accepts both unbalanced and balanced sources. The same revision is also sold as the Starkrimson Stereo Ultra DIY Kit 2.5 for self-assembly.

Key specs that matter

Output is 250 W RMS per channel into 8 ohm, with 500 W peak, and 500 W RMS into 4 ohm, with 1,000 W peak. The amplifier can drive 2 ohm and is stable into 1 ohm. Gain is 19.05 dB from XLR and 27 dB from RCA. THD is below 0.0004% at 10 W into 8 ohm, below 0.016% at 250 W into 8 ohm and below 0.08% at 500 W into 4 ohm. Signal to noise ratio is 120 dB A-weighted, with residual noise of 44.72 µV. Frequency response extends from DC to beyond 80 kHz, and the damping factor is above 700 at 1 kHz. Balanced input impedance is 44 kOhm, efficiency is about 85% and mains input covers 95 to 265 V AC. The amplifier measures 450 x 360 x 112 mm and weighs 9.1 kg.

Engineering and use context

GaN transistors switching at 0.8 MHz form the output stage, and Orchard combines them with a proprietary dual-feedback design and a fully balanced signal path. The RCA converter adds 8 dB of gain, so unbalanced sources with lower output reach full power. An efficiency of about 85% means little of the input power is lost as heat, which lets the amplifier run cool in a slim case. The very low distortion at low power matters because most listening takes place at a few watts, well below full output. A damping factor this high corresponds to an output impedance of a few thousandths of an ohm, so the load has almost no effect on the response. WBT 703-CU binding posts are standard from 1 June 2026. A 12 V trigger input with pass-through lets a preamplifier switch the amplifier on and forward the signal to a second unit. The front panel is black or brushed silver aluminium, and a version without a logo costs USD 300 extra, with silver or logo-free panels adding 10 to 15 business days to delivery. The warranty runs for one year.

Pairing

The power into low impedances suits demanding low-impedance floorstanding speakers, and preamplifiers with RCA or XLR outputs connect directly.

Alternatives

The Orchard Audio Starkrimson 25 Stereo is the 150 W class stereo power amplifier of the range.