Trilogy 921 Integrated Amplifier

The 921 is Trilogy's solid-state integrated amplifier, launched in 2023 and described by the company as its "entry level" model. Rather than build a preamplifier and a separate power amplifier into one chassis, Trilogy chose a single, ultra linear gain stage that does all the voltage gain necessary, connected directly to a compound output stage reminiscent of the larger Trilogy power amplifiers and using the same Japanese bipolar devices.

The topology has extremely high bandwidth, low distortion and very good loudspeaker control with only a tiny amount of overall shunt feedback. Rectification and the smoothing capacitor bank sit on each of the left and right amplifier modules, and a separate winding on the mains transformer feeds them independently. To keep signal and current paths short and minimise interaction between them, the layout is stacked: the voltage gain cell sits above the main circuit board that carries the output stage and power supply.

Rated output is 75 watts per channel into a recommended load of 3 to 16 ohms, from five pairs of RCA inputs. Frequency response runs 5 Hz to 100 kHz within half a decibel. The 921 is phase inverting — worth noting when setting up a system, since absolute phase can be corrected at the loudspeaker connections. The Ear made it an Editor's Choice in January 2024.

• Rated power: 75 watts per channel
• Recommended load impedance: 3–16 ohms
• Topology: solid state; single ultra linear gain stage into compound output stage; tiny amount of overall shunt feedback
• Inputs: 5 pairs RCA phono sockets; input impedance 50 kohms; sensitivity 500 mV
• Frequency response: 5 Hz – 100 kHz +/- 0.5 dB
• Distortion: less than 1% A weighted at rated output into 8 ohms
• Phase: inverting
• Power consumption: 1 W standby / 300 W maximum
• Dimensions / weight: 465 x 312 x 106 mm (465 x 350 x 106 mm including connectors) / 11 kg