Posted on Thu, 30 Nov, 2017
Posted by Bob

Sugden Audio, a British jewel in the crown of high-end Hi-Fi and a flag-waver for traditionalist Hi-Fi unencumbered by unnecessary “bells and whistles”

Since 1967, Sugden Audio have been producing very high-quality electronics and audio equipment from their base in West Yorkshire, in the UK. Proudly flying their tagline “Rescuing Music from technology”, Sugden Audio adopt a no-nonsense approach of high quality, hand built engineering, coupled with a minimalist design philosophy. A proud progenitor of solid-state Class A amplification, Sugden Audio stand out as proud mavericks in the world of high-end audio.

Today’s Audio Affair blog is a feature-length look into the history of Sugden Audio, now celebrating their 50th anniversary, and an overview of their current, superb range of Hi-Fi equipment.

Sugden 50


As is the case with many of the UK’s most prestigious Hi-Fi companies, Sugden Audio’s beginnings were rather prosaic and utilitarian. Founded in 1967 by James Edward Sugden as a division of Research Electronics, the fledgeling company originally manufactured scientific and test equipment to James Sugden’s own designs.

The test equipment found favour with universities and eventually led to Sugden’s very first audio amplifier designs; initially branded as Richard Allen and manufactured for a local loudspeaker company of the same name, the early Sugden designs showed a key design philosophy which is at the cornerstone of Sugden Audio, to this day.

James Sugden


The 1960s saw a near-universal shift away from the traditional valve (tube) electronics that had preceded and towards the then new, solid-state or “transistor” electronics. A criticism levelled at many early solid-state amplifiers was that, whilst they were much more efficient and reliable in comparison to valve amplifiers, they often lacked the “sweetness” and “musicality” of their valve ancestors.

Sugden’s amplifiers, in comparison, made a reputation for warmth and musicality, no doubt in part down to the decision to adopt a Class A design topology for their solid-state amplifiers. Class A was seen, even in the 1960s as a relatively inefficient and unpopular amplifier design; however, Class A amplifiers bypass all problems with “crossover distortion” and are famed for their warmth and musicality.

The A21 amplifier was the first amplifier Sugden manufactured and was coincidentally the world’s first Class A transistor amplifier. The relationship with Richard Allen quickly dissolved, leading Sugden to brand and market their amplifiers themselves. A testament to that original design is that an updated version of the A21 is still in production today.

Original Sugden A21

Still based very much in West Yorkshire, Sugden’s current engineering works is based in Heckmondwike. Each Sugden Audio product is still handmade by one of Sugden’s highly skilled team members; some of those employees have been with the company for over three decades, ensuring tremendous artisanal involvement with each product.

Sugden’s factory is very much a traditional audio engineering factory, with each product being machined and manufactured in Sugden’s in-house engineering and assembly shop. Everything from screen-printing to cabinet assembly is performed in-house, making Sugden Audio products that rarest of items: a truly handmade, quality British product.

Sugden Works


Sugden 21 series

Sugden’s 21 Series of amplifiers, pre-amplifiers, and CD player, reference the original Sugden A21 amplifier in their design ethos. Still very much a purist, Class A design, the Sugden A21 integrated amplifier is truly a “hall of fame” Hi-FI component, tracing its lineage all the way back to the original amplifier of 1967.

Two Variants of the A21 amplifier are offered: The updated A21 model impresses with a beautifully clean aesthetic and a sound which is equally unfussy yet famously smooth, warm and unfatiguing. Five line level inputs are provided with an optional phono stage available; power output is modest at 23 watts per channel into 8 ohms, but this is still ample for highly sensitive speakers.

Sugden A21SE

The Sugden A21SE (signature edition) takes the original A21 design and enhances it greatly for today’s more demanding customers. A greatly enhanced power supply (50% larger than the A21) and increased power output (30 watts per channel) Endow the A21SE with tremendous dynamics. Your author had the pleasure of hearing an A21SE coupled to a pair of Tannoy Legacy Arden’s recently, which was a heavenly pairing.

Sugden Grande

For those on a “Class A Pilgrimage” demanding high wattage with Class A purity, Sugden’s appropriately named Grande monoblock power amplifiers represent an uncompromising solution. Each monoblock amplifier carries one audio channel at a time, a pair of Grande being required for stereo operation.

Sugden describes the amplifier stage as, “instrumentation, class A, floating bridge power output amplifiers, dc coupled with current feedback“. Two power output levels are provided, an ‘eco level’ for low level listening where the power consumption is reduced by 75% and concert hall /auditorium level to take full advantage of the units fatigue-free uncompressed massive sound stage.

Sugden Grande

An incredible piece of engineering, each Grande outputs between 100 and 200 watts depending on the loudspeaker impedance it is paired with. Sugden has invested huge amounts of research and design in creating the Grande, with sonic performance and product longevity high on the agenda. Surely, one of the world’s greatest power amplifiers.

Sugden Masterclass

Sugden’s Masterclass series represents very much the “bread and butter” of Sugden’s high-end Hi-Fi components; in continuous production for over seventeen years, the Masterclass has received awards and accolades from dedicated audiophiles and the Hi-Fi press alike. Like all of Sugden’s products, each Masterclass is handmade at the Sugden engineering works in Yorkshire, England by a single, highly skilled technician.

Sugden Masterclass

The Masterclass range comprises of pre-amplifiers, power amplifiers, integrated amplifiers, a DAC and a CD player; let’s take a quick overview of the range:

Power amplifiers in the Masterclass series start with the FPA4, a pure Class A, stereo power amplifier offering 25 watts per channel when fed from either its balanced or unbalanced inputs. Moving up in power and cost, we find the MPA4 and SPA4, essentially mono and stereo versions of the exact same amplifier.

The MPA4 offers 75 watts of warm, musical Class A amplification and can be fed with either an unbalanced RCA connection or a balanced XLR. The SPA4 is effectively two MPA4 amplifiers in the same enclosure, saving space and creating a more convenient package.

Sugden Masterclass SPA4

The Sugden LA-4 pre-amplifier is an ideal match for any of Sugden’s Masterclass or Sapphire power amplifiers; indeed its high-quality design makes it a superb preamplifier for any situation. A premium construction including gold plated circuit boards, relay switched inputs and outputs and being Sugden, a sophisticated class A output stage.


Looking for the power and audio quality of the Masterclass pre and power amplifiers in one convenient package? Then look no further than the IA-4 Integrated Amplifier; Sugden’s flagship and most popular integrated amplifier. A useful 33 watts per channel with plenty of input and output facilities make the IA-4 one of the world’s premier Integrated amplifiers.

The Masterclass series also comprises of the PDT-4F combined CD player DAC, and a number of “problems solvers” such as the high-end PA-4 phono preamplifier, the HA-4 headphone amplifierand the DAC-4 Digital to Analogue Converter.

Sugden Sapphire

Sugden describes the Sapphire series as, “Purist amplification for the connoisseur“. Sugden’s premium pre/power combination, the Sapphire series represents Sugden approaching their Class A philosophy from a truly modern perspective.

Sugden Sapphire

The DAP-800 preamplifier could well form the control centre of your audio system. A total of six analogue inputs and six digital inputs are available as well as two single-ended and one balanced output. Utilising the same DAC circuitry as the standalone DAC-4, but with separate power supplies for analogue and digital sources, the DAP-800 could well be the last pre-amplifier you ever buy!

The accompanying FBA-800 power amplifier represents Sugden’s most advanced power amplifier. Employing a floating bridge design, combining four 20 Watt amplifiers in a single stereo chassis. Uniquely, this makes the FBA-800 a balanced design from input to output; quite remarkable!

Sugden Speakers

The relatively low output of some of Sugden’s amplifiers, demands sensitive, quality loudspeakers to allow the amplifiers to really shine to the maximum. It stands to reason then, that Sugden manufacture highly sensitive loudspeakers, which are equally well crafted.

Sugden LS21

The LS21 loudspeakers utilise a tuned, quarter wave design and employ a treble and mid/bass driver ported through the plinth. The plinth also houses the bespoke crossover unit, in order to isolate it from vibration.

The artisanal, furniture grade cabinets are crafted entirely in-house in Sugden’s wood-working facility; carrying through Sugden’s philosophy of hand-crafted, quality products to last the user a lifetime.

Sugden – Hand-Made British Quality

In an era of increasingly fashion-led, disposable technology, Sugden’s philosophy of timeless designs, world-class sound quality and engineering meets artisanal construction is deeply satisfying.

Sugden is one of the few manufacturers which will still service any Sugden product, even going back to the original 1967 version of the A21. With that said, Sugden has bowed to one fashion concession, and that’s to add a third, attractive finish to their range of Hi-Fi.

If you like your Hi-Fi to have a touch of the Darth Vader to it, then take a look at the new Stealth finish option. Whatever your choice, Sugden Hi-Fi represents a solid investment in your Hi-Fi enjoyment for years to come.

“Sugden Audio – Rescuing Music From Technology”

Sugden Stealth

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