Regular customer will now that we sell a fairly wide range of electronics and we do so to offer a choice of what we believe (and our ears tell us) are the best at a given price. Amongst these excellent amplifier designs nestles Yorkshire's very own Sugden and two amplifiers which are so special that they are quite unique.
Sugden was founded by James Edward Sugden in 1967, a division of Research Electronics. Research Electronics manufactured scientific instruments and test equipment designed for Universities. The A21 was the first audio product to be put into production and was originally branded for a well known local loudspeaker company called Richard Allan.
The A21 was the worlds’ first production pure class A transistor amplifier and a great success.
Class A amplification is a type of analog amplifier operation where the transistor conducts for the entire 360° of the input signal cycle. This means that a Class A amplifier, the transistor is always on. Even when there is no input signal, current still flows through the device. The input signal simply modulates that constant current.
How it works (simple view)
- The transistor is biased in the middle of its operating range.
- When the input signal increases, the current increases above the idle level.
- When the input signal decreases, the current decreases below the idle level.
- Because the device never switches off, the output waveform is very faithful to the input.
Advantages
- Very low distortion
- Excellent linearity
- Simple circuit design
Disadvantages
- Very inefficient (typically ~20–30%)
- Produces a lot of heat
- Requires larger power supplies and heat sinks
- Low power (relative to other designs)
The basic design of the Sugden A21 hasn't changed a great deal since the late sixties. But it has been refined with regard to heat dissipation, chassis design to aid this and component improvement.
Currently Sugden make two versions of the A21 and we stock them both. They offer something quite unique and much closer to valve designs in their sound. And they have enough power to drive most loudspeakers very well up to an including normal listening levels. They do this with a musicality and warmth which is akin to feeling the sun on your skin.
A21 Signature
RRP £2998 in silver or black
Technical Specifications
Gross Weight (packed): 11kgs
Line Input Sensitivity: 170mV for max. out
Phono Input Sensitivity: 3mV/mm, 0.2mV/mc for max. output
Phono Loading: MM 47K MC 470 Ohm
Power Output: 23 Watts into 8 Ohms
Frequency Response: +/-1dB 10Hz-20kHz
Bandwidth: 6Hz-200kHz
Signal to Noise: >83dB
Sugden A21 Special Edition
- RRP £3995
- Line Input Sensitivity: 171mV for max. out
- Power Output: 30 Watts into 8 Ohms, 40 Watts into 4 Ohms (Both Channels)
- Frequency Response: +/-1dB 12Hz-141kHz
- Bandwidth: 6Hz-280kHz
- Signal to Noise: >90dB
- Gross Weight (packed): 15kgs
- Dimensions: 115 x 430 x 360mm (hwd)
Many customers have been fooled by the relative low power rating of both these designs. They're both capable of producing beautiful music in real-World rooms with most loudspeakers. We invite you to listen to them and hear just what is so special about these designs. Once heard, never forgotten.