Sugden Masterclass IA-4 and PDT-4

By Michael Wong

August 2008

Sugden Masterclass IA-4 Integrated Amplifier $9899, Masterclass PDT-4 Precision Digital Transcriptor $8499


The Sugden Masterclass amplifier and CD player (click for larger image)

Another view of the IA-4 integrated amplifiers (click for larger image)

Many audiophiles will be unfamiliar with the Sugden name but JE Sugden & Co. Limited is one of the most enduring names in UK hi-fi, having been in business continuously since the 1960’s. The company has it’s origins in specialised laboratory and test equipment. The A21 integrated amplifier sealed the company’s place in audio history by being the first commercially available solid state Class A amplifier, a breed that would be later popularised by American heavy hitters like Mark Levinson and Krell.

The Sugden name soon came to be held in the same high regard as illustrious UK amp makers like Naim and Quad. The A21 is still in production, updated with modern production techniques, components and aesthetics.

Sugden is now represented in New Zealand by Steve Seque of Soul to Sole Audio, the Hawke’s Bay company best known for their superb audio racks.

The IA-4 is a stolid beast, facing the world in true Yorkshire fashion with a thick, no nonsense aluminium faceplate. The Sugden offers three single-ended line inputs, one balanced input, MM phono, tape. On the rear are single-wire speaker binding posts (unusually equipped with locking collets to tightly clamp banana-type plugs), vertically arranged RCA input connectors, a set of balanced XLR inputs, and RCAs for tape and preamp outputs.

The PDT-4 shares the amp’s minimalist control layout with basic transport controls on the front. The rear carries quality RCA and XLR connectors, an RCA digital output and unusually for a CDP, a heatsink.

A generic plastic remote offers full CD operation but only volume control for the amplifier. Both units are fairly well made but not quite up to the finish expected of a $10k audio component. The amp had a rattly lid and the CDP a nasty looking plastic disc tray which fitted poorly in the fascia cut-out.

The Sugdens were auditioned primarily as a pair, with associated equipment from Well-Tempered, Plinius, Marantz, Denon, Nakamichi, OPPO, Krell, Magnepan, AR, Energy, XLO, Audioquest and DNM.

Turning on

Push what must be the world’s largest on/off button and after short delay you will be greeted by a gentle click as the protection circuit disengages. Peek through the ventilation slots on the lid and you will see two LEDs light up. An LED near the front briefly lights up when the remote is used. Very cool. Not so cool is the cramped action of the volume control and the noise of the motor drive when adjusting volume by remote control.

Warm up time is short at around ten minutes. The sound is immediately relaxed and inviting. Within the limitations of its modest output (33wpc into 8 ohms, 40-something watts into 4 ohms), the amp is effortlessly musical. Spatial performance is very good with the performers and instruments in a clearly defined acoustic, reproduced with a palpable presence and ambience.

Imaging is a little smaller than life, say 9/10s scale. Focus is very good without the etching that can occur with some solid state amps. Tonality is good with a smooth, lifelike midrange, there’s just a slight sweetening and a bit of high end softness, curious given the astounding 300 kHz high frequency bandwidth. Bass is fulsome and articulate. Very good detail and transparency provides plenty of insight into the music.

Dynamics are generally good with just a wee softening of initial transients. Vocals and simply recorded material sound rich and very lifelike but the amp can be caught out trying to reproduce large scale dynamics or complex music. You will soon know when the Sugden’s reserves are exceeded as its clipping behaviour will be painfully obvious, the soundstage collapses, accompanied by tonal hardness and distortion. Keep a close eye on the volume and the amp can be very forgiving, highly listenable and comparable to the best amplifiers I have heard in the very competitive sub-$10,000 price band.

The PDT-4 CD player’s performance is almost as impressive. The sound is clean and musical, sharing much of the amp’s sonic characteristics. There’s a slight loss in immediacy and palpability to the sound as well as a general sense of the sound being a little dry and shut-in on top and a tad loose on the bottom. The Sugden is very pleasing to listen to and stands comparison with other CDP’s in the sub-$10k band, with the bonus that this player is easier to use than most, unburdened with the frippery like switchable filters etc. that plague other high end players.

As solo performers these two Sugden pieces impress with very respectable performances. Use them together and they really shine with excellent greater-than-the-sum-of-the-parts synergy, opening a sizeable window onto the musical performance. The sub-$10,000 audio market is extremely competitive with many excellent local and imported products. These Sugdens may look out of place with their homely looks but close your eyes and they will stun with their superb musicality.

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