Pre-owned D'Agostino Progression M550 Early Build Monoblock Amplifier

Every so often, a piece comes through that the spec sheet doesn't fully explain.

This is an early Progression M550. The full M550 circuit. The full M550 power supply. Built before the second-generation chassis arrived with its larger heat sinks. D'Agostino made it this way — and that is the part that matters. The amplification is all here.

550 watts into 8 ohms. 1,100 into 4. 2,200 into 2. The output doubles as the load halves. That is the number to read. It tells you the power supply is real, and most are not.

What the earlier chassis gives up is heat sink mass. In practice, it means this amp is not designed to hold full rated output for extended periods without rest. No one listens that way. Music lives in the transient — the strike of a piano key, the leading edge of a cymbal. Brief, enormous demands. This amplifier meets them in full.

D'Agostino's circuit, at a price the upgrade cycle opened up. If you already know what that circuit does in a room, this one is worth a conversation.

*Stock photos shown