Integrated amplifiers — Sugden Audio MASTERCLASS IA-4

The MASTERCLASS IA-4 is an integrated amplifier from Sugden Audio, part of the brand's flagship Masterclass series, built with comprehensive five-input connectivity including a dedicated phono input. The MASTERCLASS IA-4 brings Sugden's most storied Class A engineering heritage to a complete integrated chassis.

Key specs that matter

One balanced XLR input plus four single-ended RCA inputs and a dedicated phono input are provided. Input sensitivity is 125mV. Output power is a modest 33W into 8 ohms - a figure consistent with genuine Class A operation, which trades raw output for exceptionally linear, low-distortion performance. Frequency response spans an extraordinary 14Hz to 200,000Hz within plus-or-minus 3dB - a remarkable bandwidth. Signal-to-noise ratio exceeds 84dB. At 165 x 430 x 440mm and 20kg, the MASTERCLASS IA-4's considerable weight relative to its modest output reflects the substantial heat-sinking and power-supply componentry genuine Class A operation demands.

Sound and use context

Expect the exceptionally smooth, linear character genuine Class A amplifier operation is broadly celebrated for, combined with the extraordinarily wide 14Hz-200kHz bandwidth, representing Sugden's flagship-tier current Class A engineering ambition.

Pairing

The built-in phono input covers a turntable directly, and the modest 33W Class A output pairs best with efficient, high-sensitivity loudspeakers.

Alternatives

Sugden's own A21 offers a more accessible alternative within the same broader Class A integrated amplifier catalogue.