Sugden FPA 4

Sugden FPA 4, Pure Class ‘A’ Stereo Power Amplifier

The FPA-4 power amplifier is the newest member of the Sugden Masterclass family. A pure class ‘A’ power amplifier of 30 watts per channel. This output stage is of the classic Sugden single-ended design that has been providing musical enjoyment to thousands of music lovers for many years.

The amplifier’s features include a Phono (RCA/asymmetric) stereo pair and a pair of stereo balanced XLR input connectors. Output is through two pairs of stereo speaker terminals with facilities for Spade, Bare wire or Speaker Jack Connectors.

Balanced input

The balanced input is connected to left and right virtual transformer circuits to convert the signals to single-ended. This allows for the advantages of the balanced input, which, along with the excellent performance of the unbalanced circuitry, offers the potential for simply more music.

The amplifier’s input stage (a new design) has been developed to enhance overall performance and further exploit the potential of the class ‘A’ output stage. It exhibits characteristics of a very good tube amplifier with soft clipping and low internal overloads. The phase shift at high frequencies is also extremely low, resulting in a very open, uncompressed sound image without fatigue.

The amplifier benefits from a comparison and correction circuit, so that errors that would occur in the output stage due to variable loads and distortion are corrected to match the output of the high-impedance input amplifier. While maintaining signal authenticity, it also increases load stability and forces the output impedance to zero.

The amplifier with Sugden error correction has a very low open-loop output impedance resulting in a high damping factor at quite high frequencies.

The connection of the amplifier output to the selected speakers is done via a ‘soft coupling’ protection circuit board. It is a static contact switching circuit board that uses very low ‘resistance’ power MOSFETs. These devices are switched on and off to enable a noiseless connection to the speakers, regardless of their sensitivity.

This amplifier, like other Sugden amplifiers, is designed and developed to provide the ultimate musical enjoyment from the numerous storage/reproduction sources for music that exist today.

• Sugden FPA 4 Specifications:

Input sensitivity – 1V for full output.

Power – 30 Watts into 8 ohms both channels active (dependant on input voltage).

Frequency response – 0dB 18Hz – 95kHz.

Bandwidth – 3dB points 10Hz – 125kHz.

Signal-to-noise ratio – >82dB.

Distortion at 1 Watt, 1 kHz – <0.04%.

Net weight – 15 kg.

Dimensions – 143 x 430 x 350 mm (hbd).

Available in Titan/Graph/Stealth.

*Contact us for current stock and/or delivery information.”