Trilogy 921 Integrated Amplifier

A tough design challenge was to give the Trilogy 921 Integrated Amplifier the fluidity and sheer musical involvement that typically only valve amplifiers enjoy. But in the Trilogy fashion of going against the flow…

Rather than design the 921 as a pre amplifier and a separate power amplifier in one chassis, we chose a single, ultra linear gain stage that does all the voltage gain necessary. This is then directly connected to a compound output stage reminiscent of our larger power amplifiers, enjoying the same Japanese bipolar devices.

This topology has extremely high bandwidth, low distortion and very good loudspeaker control with only a tiny amount of overall shunt feedback.

The rectification and smoothing capacitor bank are on each left and right amplifier module and a separate winding on the mains transformer feeds these independently.

To make signal and current paths short and to minimise interactions between them, a stacked approach is used to enable the voltage gain cell to sit above the main pcb where the output stage and power supply exist.

Technical Specifications

Size (W x D x H): 465 x 312 x 106
Size including connectors (W x D x H): 465 x 350 x 106
Weight: 11 Kg
Standby Power Consumption: 1 Watt
Maximum Power Consumption: 300 Watt
Input: 5 pairs RCA phono sockets
Input Impedance: 50K Ohms
Input Sensitivity: 500mV
Rated Power: 75 Watts per channel
Recommended Load Impedance: 3-16 Ohms
Frequency Response: 5-100KHz +/- 0.5dB
Distortion: Less than 1% A weighted at rated output into 8 Ohms
Phase: Inverting