Solid State Amplifiers

We are involved in an extensive listening programme to re-evaluate some of our amplification brands. What we do not like is a bright and forward presentation of which there are, sadly, many examples. Whatever we choose will be based on a natural, more realistic presentation of music reproduction, similar to that experienced in a concert hall.

One of the best amplification systems we have heard over the years is from Spectral Audio. This was one of our reference sounds. Unfortunately this brand is no longer represented here in the UK but it remains the sound to measure others by. We took on Edge Electronics which is very close to their philosophy of tonal accuracy, speed and 3-dimensional holographic sound stages, and in some areas surpasses Spectral Audio. Easily rivalling Boulder, Constellation and Solution but at lower prices.

Norma Audio, a little known brand from Italy has astonished us by how good a sound their products can achieve for a modest investment. Their products offer a true high-end sound at medium level prices with their entry level products. For once, their value-for-money options compare very favourably to some of the hgh priced offerings from the more obvious, heavily marketed brands.

At their Reference level, Edge Electronics is on a par with our favourite Spectral Audio in terms of speed, dynamics, tonal accuracy and probably exceeds it in terms of sound stage scale and depth. 

We have listened to Pass Labs, Luxman, Vitus and Jeff Rowland Design. These brands have not really come up to what we look for in terms of sound stage and tonal correctness. Audio Analogue, with their new Anniversary remodelled products, and Hegel have impressed us enough to add to our portfolio. We have evaluated some splendid amplifiers from AVM and these are now with us. 

 

Heralding from Germany, AVM have been developing and manufacturing electronic equipment ‘for the highest quality of musical reproduction’, for more than 30 years. They have been producing this, with the goal of delivering ‘joy and emotion to the listener’. All the design and development is done in-house and all models are fully manufactured in their own German factory.

During our investigations, we were impressed with their quality of musical reproduction, along with their striking looks and their outstanding build quality. They aim to use simple, logical design principals to achieve optimal performance levels. Because they do not design unnecessarily complicated circuits, there is less requirement to use compensating components for them to function correctly. This allows for a focus on the best components, and by carefully selecting these electrical components there is less of a fingerprint or character imposed on the musical reproduction.

AVM offers a range of equipment encompassing Amplification (Pre/Power & Integrated options), CD & Streaming, All-In-One units, Turntables and a Phono Stage.

AVM Streaming CD Receiver

The EVOLUTION CS 5.2 Compact Streaming CD Receiver is a very interesting and versatile all-in-one unit. One of the more recent trends in hi-fi is for ‘lifestyle’ units, these being smaller and with the ability to do more from a single chassis. This unit takes these principles to a new level of sound quality without serious compromise. We were impressed with the CS 5.2’s range of talents and sonic character delivering great dynamics and a very natural timbre. Exceptionally rare with such all-in-one designs.

Firstly, there is a very powerful amplifier delivering 2 x 220 wpc at 8 ohms (2 x 330 wpc at 4 ohms), with 2 sets of switchable speaker outputs.

Next, contained within, is a TEAC based ‘Pure CD Drive’ to give outstanding CD reproduction. It is acoustically shielded and spring-mounted to protect from unwanted resonances and structural feedback loops.

Connectivity is ample with 4 analogue line inputs and 1 phono input (for both MM and MC). To compliment this it has a range of digital inputs (Coax, Optical and USB). There is both a pre-out and line-out.

This unit can also stream from the Network (LAN, UPnP or Wi-Fi) including from a NAS, from a hard/thumb drive (as the CS 5.2 has no internal storage/ripping capability), or from web services such as QOBUZ, TIDAL or internet radio. The streaming client firmware is updateable and upgradable, making the CS 5.2 future-proof. It also includes a RDS FM tuner.

It is fully controllable through vast menu functionality including; tone controls with bypass function, adjustable input sensitivity, individual naming of inputs etc. It is remotely controlled using either the RC S remote control app (for free download for both Apple iOS and Android) or the optional RC 9 full colour remote control.

As a bonus, it also has a high quality pure Class-A headphone amplifier with 6.3 mm output.

EVOLUTION CS 5.2 Compact Streaming CD Receiver – black or silver £5750

AVM website

EVOLUTION MP 5.2 CD Player & Streamer
EVOLUTION CS 5.2 Compact Streaming CD Receiver

Integrated Amplifier

The OVATION A 6.3 Integrated Amplifier is a Class A/AB high current MOS-FET design from AVM’s flagship OVATION series and is a very versatile unit. In our listening tests we thought it delivered true sonic thrills, with great drive and dynamics –both macro and micro - with a very live and musical presentation. As well as the sound quality, the build quality is exceptional, even at this price level.

The amplification section provides 2 x 200 wpc at 8 ohms (2 x 330 wpc at 4 ohms) through 2 sets of speaker terminals. It has a very interesting design topology using 20 MOS-FET transistors per channel to deliver up to a huge 180 amps of current and has a fully balanced and DC coupled input stage.

Connectivity is plentiful with 5 high level analogue inputs consisting of 1 XLR balanced and 4 RCA unbalanced, along with analogue outputs consisting of 1 line-out (RCA), 1 pre-out on RCA and 1 x XLR.

Complimenting the analogue inputs there are a range of digital inputs too. These consist of 1 RCA Coax, 2 Toslink Optical, 1 USB with up to 384 kHz / 32 bit & DSD 128. Finally, there is the inclusion of Bluetooth 4.2 for a wireless option.

Headphone users are supplied with a pure Class-A headphone amplifier with 6.3 mm output.

There is also a home theatre/AV bypass mode through both analogue and digital inputs. This allows easy home cinema integration, where this unit would be used as the power amplifier to the main speakers, controlled by an existing pre-amp processor.

Unusually, there is the ability to adjust bass, treble, contour (loudness) and balance to make room integration easier. The unit can be controlled from the included RC3 remote control (or optional full colour RC 8) and is available in silver or black and is delivered in an OVATION flight-case.

OVATION A 6.3 Integrated Amplifier – black or silver £9900

 

OVATION A 6.3 Integrated Amplifier
OVATION A 6.3 Integrated Amplifierer

We have evaluated the new Pure AA designs from this long established Italian company. In particular, the heavily re-designed Puccini Anniversary integrated amplifier is a very impressive product, quite an advance in sound over its original version. The tonal balance is very natural, but very dynamic when called for. A large and deep soundstage which is always something that appeals to us. Dual mono in its layout, with inputs separated left and right, and handed. One very large toroidal transformer and a power supply giving 25 amps current. Audiophile grade components abound including the high quality RCA inputs and winged speaker terminals. It delivers an understated 80 wpc into 8 ohms, which is more like 100 wpc and 185 wpc into 4 ohms. More than capable of keeping most speakers under control. The most important thing is the sound: very elegant and smooth but not euphonic or lacking in detail. Even played loud it retains its composure. Quite a different refined presentation setting it apart from the more usual competitive brands in this price point.

The Maestro Anniversary integrated amplifier takes this design philosophy to a much higher level with the dual mono, fully balanced, zero feedback design that includes two transformers. Output jumps to 150 wpc into 8 ohms and 300 wpc into 4 ohms, probably conservative ratings.

This is one of the best integrated amps we have heard in a long time delivering huge 3-dimensional sound stages with a very natural tonal balance. Again superb dynamics and will drive most speakers with ease. Both the Maestro and the Puccini employ zero global feedback technology.

We have just had the pleasure of auditioning the Bellini Anniversary pre-amplifier with the matching Donizetti Anniversary power amplifier. All dual mono, zero feedback designs; output from the stereo amplifier is 250 wpc/8 ohms and 500 wpc/4 ohms. Sonically very similar to the splendid Maestro Anniversary, as one would expect, but the authority and extension to the bass is raised to a higher level. Superb build quality and value for money compared to the obvious competitors.

There is an entry level integrated amplifier in the AA range called AACento which is not dual mono in design and is built to slightly lower specification but offering superb value at its price point. It includes a phono stage and headphone output.

AACento integrated amplifier – 100 wpc/8 ohms £2999
Puccini Anniversary integrated amplifier – 80 wpc/8 ohms £3749
Maestro Anniversary integrated amplifier – 150 wpc/8 ohms £6999

Bellini Anniversary pre-amplifier £4999
Donizetti Anniversary stereo power amplifier - 250 wpc/8 ohms £8999

All models available in black or silver.

Audio Analogue website

AACento integrated amplifier
AACento integrated amplifier
Puccini Anniversary integrated amplifier
Puccini Anniversary integrated amplifier
Maestro Anniversary integrated amplifier
Maestro Anniversary integrated amplifier

Once in a while comes along a product that is so different in sound from the rest of the pack that you start to have few doubts about what you are hearing. Why is this so good to listen to, you ask yourself? The answer isn’t so obvious to determine just by looking at the specification sheets but these electronics distance themselves from the sound of others in the already crowded high-end market.

We have evaluated samples from both the reference NL series pre and power amplifier range and from the more affordable G series. The sound is so natural, so neutral without any obvious colouration, emulating the feelings one gets from listening to the very best pure Class A valve amplifiers but with the authority that comes with ample power. This is a remarkable achievement particularly when considering that this is from what is a very powerful solid state design which is not Class A. Huge power supplies, massive current delivery and, in the NL range, pure and highly symmetrical dual mono design in one chassis clearly show exceptional attention to good design philosophy. Transparency, some call this clarity, is of the highest order with an exceptionally low noise floor. Probably the best we have ever heard. The soundstage is wonderfully holographic both on the macro and micro scales emulating that normally heard with Class A amplification. Notes are presented at correct timbres; harmonics and decay are delivered so realistically giving a real sense of a presence to the instrument or voice being listened to. High current delivery when required results in dynamics being extremely fast; effortless and powerful at the same time. Power with elegance. Edge engineers say ‘that’s low level linearity’. The NL range is now our reference point amplification system.

The G Series, whilst not at the NL Series level, does offer much of the house sound and philosophy at more affordable prices. It even comes through in the G3 integrated amplifier. An exceptional achievement when one considered the sound quality against the asking price. Small chassis that are easy to accommodate in most equipment supports. An initial impression of the style of the chassis would indicate a slightly fussy and retro appearance. On closer examination, it is clear that the engineers have built this in an unconventional way, constructed from separate sections of metal strategically bolted together rather than a chassis made from the usual bent, relatively thin sheets of aluminium. This results in a chassis that is very stiff with thicker than average metal work, which is less prone to the degradation effects from unwanted resonance feedback, a very common problem with many, even expensive, amplifier brands.

We strongly urge you to audition this amplification design. It is likely to change your perception of what musical reproduction is capable of.

G Series

G3 integrated amplifier – 115 watts, 6 amps (pictured) £9900
G2 pre-amplifier – battery & AC powered £8500 
G6 power amplifier – 135 watts, 14 amps £7000 
G8 power amplifier – 175 watts, 18 amps £10900
G10 mono amplifiers – 200 watts, 26 amps £19500 pair

NL Series

NL Signature 1.2 SE pre-amplifier – battery & AC powered (pictured) £19900
NL 10.2 power amplifier – 225 watts, 28 amps  £24000 
NL 12.2 power amplifier – 300 watts, 56 amps (pictured) £32000
NL Signature 1.2 mono power amplifier – 400 watts, 83 amps £58000 pair

Please note the power rating quoted above is watts per channel into 8 ohms load.
The current rating quoted is constant, not peak. Peak current would be approximately 4 times the figure quoted.

Edge Electronics website

G3 integrated amplifier
G3 integrated amplifier
NL Signature 1.2 preamplifier
NL Signature 1.2 preamplifier
NL10.2 amplifier
NL12.2 power amplifier

This Norwegian electronics company has been around since the mid-1990s but in recent years has become much better known in the higher end of the audio market. They have a very focused range of products which include five integrated amplifiers, two pre-power amplifier combinations. All these amplification systems utilise their unique design “SoundEngine” which is a local error cancelling system preventing distortions in the audio amplifier circuit stages whilst preserving the fine details and the dynamic range of the original recorded music signal. The SoundEngine Technology cancels crossover distortion found in all types of class-AB amplifiers and the human ear is very sensitive to high frequency distortion components in the music signal. The result is a much cleaner, organic sound with a larger dynamic range and lower distortions.

Our listening tests confirm that the sound of Hegel amplification is quite distinct to many other mainstream brands. A significantly lower noise floor, more transparency that allows low level aural clues to be heard easily. Not at all bright or forward, with a natural, organic tone marginally on the warm side of neutral. The result is a less transistor-like sound. Large three-dimensional soundstages and fine detail are excellent as you would expect from a company that takes low distortion and low noise as its priority.

All Hegel integrated amplifiers incorporate sophisticated DAC designs that allow all digital sources to be played easily. These keep and plays the digital source in their original native format throughout for the best sound quality.

Their integrated amplifiers show marked improvements as you go up through the model range, from the Röst, the H190 and to the new H390. All offer a superb sound and value for money at their respective price points.

The new H390 replaces the long standing H360, which for us was the  value for money model in the range. This new integrated model has  lot of trickle down technology from the flagship H590 and is a significant improvement in sound over the H360. It has an improved power supply with a large transformer, and a completely dual mono circuit layout. The inboard DAC is particularly impressive and superior to that in the outgoing H360. Very dynamic, fast and capable of delivering large sound stages. 

The new top of the range integrated amplifier from Hegel, the H590, is a beautifully compact and elegant design. It offers a sound that will compete very easily with many of the top brands in the high-end audio market at a substantially lower price. An innovative dual mono design from the pre-amplifier, with its dedicated high-quality power supplies and a unique volume attenuator, to the massive output stage using 12 ultra-fast high power output transistors per channel. This amplifier is super fast and will drive any speaker load with ease. A compact, one box amplifier that delivers true high end performance. 

Compared to the H390, the H590 has a superior pre-amplifier in the analogue section and a marginally improved DAC for streaming. Whether you play CD format or high resolution files as a source, they will all benefit from the sophisticated DAC incorporated. Using the USB input, the H590 will also support high end formats such as DSD. It also includes MQA decoding and rendering technology, which enables you to play back MQA audio files and streams, delivering you the sound of the original master recording.

A truly innovative product for those wanting high-end sound at a realistic price. Whilst the price is not insignificant, it offers a compact solution, exceptional sound, and superb value for money.

H90 integrated amplifier – 60 wpc/8 ohms £1500
Röst integrated amplifier – 75 wpc/8 ohms £2200
H190 integrated amplifier – 150 wpc/8 ohms £3200
H390 integrated amplifier, dual mono – 250 wpc/8 ohms £4900 (due September 2019)
H590 integrated amplifier, dual mono – 301 wpc/8 ohms £9000

P20 Balanced Pre-Amplifier £2250
P30 Balanced Pre-amplifier £5000

H20 Power amplifier, dual mono – 200 wpc/8 ohms £4150
H30 Power amplifier, mono amplifier – 1100 wpc/8 ohms £11000 each
(can be used as a stereo amplifier and converted back to mono)

Hegel Music Systems website

Röst integrated amplifier
Röst integrated amplifier
H190 integrated amplifier
H190 integrated amplifier
H390 integrated amplifier
H390 integrated amplifier
H590 integrated amplifier
H590 integrated amplifier

Norma Audio Electronics

This is a superb sounding amplifier and electronics manufacturer from Italy. Little known in the UK but well established throughout Europe as a worthy partner with many speakers but work very well with German Physiks, ProAc and Elac loudspeakers. Well built on genuine dual mono design including two transformers -the exception being the IPA-70B integrated amplifier. High quality component count, high capacitance power reserve capable of delivering high current resulting in a very fast sound. An elegant Italian designed chassis rivalling the quality from the best from more famous high end manufacturers. Refined and elegant tonal balance with a natural presentation of a deep soundstage. A true high end sound quality at moderate prices.

There are no bargains in audio, but this is an amplifier that can go up against amps costing £12,000-£16,000 despite costing the right side of £5,500 in its all up top spec guise. The hifi market can be fickle, but the IPA140 has some real staying power. I think for many, to try it will be to love it.
Alan Sircom, HiFi+

REVO IPA70B integrated amplifier 70 wpc/8 ohms 24A constant current, 100A peak
Silver £3475 
Black £3610 

REVO IPA140 integrated amplifier (pictured) 140 wpc/8 ohms 36A contant current, 150A peak
Silver £5695 
Black £5865

PH1-REVO phono board for IPA70B £219 
PH2-REVO phono board for IPA140 £389                              
USB1-REVO USB 196kHz/24bit board for IPA-70B £549 
USB2-REVO USB 196kHz/24bit board fro IPA-140 £549

REVO SC-2LN line stereo pre-amplifier
Silver £5695 
Black £5864

PH3-REVO phono board for SC2LN £389                              
DAC1-REVO DAC board for SC-2LN; 5 digital inputs 4 x SPDIF,USB, 192kHz/24bit. £1999 
MCH6-REVO Multichannel Option, 2 sets of 6 channel inputs. £1499 

REVO PA150 stereo amplifier 150 wpc/8 ohms 48A constant current. 200A peak 
Silver £5595 
Black £5764

Modular Integrated Amplifiers - HS Series

HS IPA1 integrated amplifier 75 wpc,/8 ohms; 24 amps constant current, 100 amps peak. Includes phono board MM & MC; DAC with 5 digital inputs 4 x SPDIF, USB, DSD compatible; Headphone amp
£3650 silver
£3729 black

HS IPA1 integrated amplifier 75 wpc,/8 ohms; 24 amps constant current, 100 amps peak.
£2595 silver
£2674 black

DAC1-HS DAC board for HS IPA1 £675
PH1-HS Phono board for HS IPA1 £225
HEAD1-HS Headphone option for HS IPA1 £225

Norma Audio Electronics website

REVO IPA70B integrated amplifier
REVO IPA140 integrated amplifier

PS Audio 

PS Audio has launched a new range of amplification called Stellar. They offer exceptional audiophile sound quality at truly affordable pricing in a market where spiraling cost-no-object equipment abound. The amplifiers combine discrete Class A analogue stages for the all-important input stages with ultra linear Class D technology for the output stages. The Gain Cell DAC/pre-amplifier is also a unique design combining a state of the art DAC with a Class A pre-amplifier and analogue volume control. The sonic results are more than the sum of these parts, offering a sound of a high level of elegance higher than you would expect from the price point.

PS Audio Stellar Gain Cell DAC

The heart of the system is the Gain Cell pre-amplifier, a pure Class A pre-amplifier combined with a refined and improved version of their NuWave DSD capable DAC. There is no better way of sending a DAC signal to a power amplifier than via a good analogue pre-amplifier where the output is controlled by an analogue volume control. PS Audio has put both into one chassis and all you need to do is add your sources, digital or analogue. A full complement of inputs to cater for computer sourced files, pure DSD and asynchronous USB, as well as I2S for CDs from a transport or vinyl via the analogue inputs from a phono stage; a complete pre-amp and DAC in one chassis.

The PS Audio Gain Cell relies on a different technology known as a variable gain amplifier (Gilbert Cell). This topology was invented in the 1960’s by Howard Jones and Barry Gilbert and widely adopted by recording and mastering studios in their analog heyday—later abandoned when these same studios went digital. The idea behind the Variable Gain Cell is simple. Instead of adding additional circuitry to the signal path to vary loudness, the preamplifier’s actual amplifier stage varies its gain in response to the user’s front panel volume control. This method requires zero additional circuitry in the signal path, offers more than 80dB of attenuation

Fully balanced circuitry used throughout for those that prefer this principle although 3 non-balanced analogue inputs are included. Build quality and case work design are also excellent with a very solid feel to it. All Stellar products are hand built in Boulder Colorado, USA.
A long burn-in time is required, as is the case with many designs featuring high quality components, and once complete the sound is exceptional for the price asked. A rich sound without being too warm and powerful dynamically. Good holography and sound stage which pleased us as it is not often the case with many competitors at this level.

Stellar S300 Stereo Power Amplifier

This stereo power amplifier is a dual mono amplifier design in one chassis capable of effortlessly driving demanding loudspeaker loads to concert levels. The S300 combines an ultra linear, high-current, Class D technology for the output stage with a discrete Class A MOSFET based Analog Cell for the all-important input stage. The S300’s rich and engaging sonic character comes from the Analog Cell design. Its powerful, authoritative control over the loudspeaker stems from its high current, ultra-low impedance Class D output stage. Effortless dynamics with a spacious 3-dimensional stage, no hint of aggression or forwardness which can be common with Class D designs.

Stellar M700 Mono Power Amplifiers

The M700 mono amplifiers are a more powerful design taking the principle of the S300 stereo amplifier to a higher level. Two chassis with two completely independent power supplies provide more power and more current to give increased headroom on dynamic music. The M700 uses unique topology in the Analog Cell to preserve the fine details found in quality recordings. The Analog Cell is zero feedback Class A, balanced MOSFET input stage which closely mirrors the sonic characteristics of a vacuum tube.

Loud and complex musical passages are effortlessly rendered but even the tiniest nuances in the music are easily perceived from a transparent background. Overtones from plucked instruments, subtle cues that define stage placement, the depth as well as width of the soundstage, transient decays which are often lost in the very powerful amplifiers. The Stellar mono amplifiers surprised us with their ability to capture the rich full-bodied essence of recorded music and present it with authority and grace. A very natural presentation, never forward and lacking in glare common at this price level.

Stellar Gain Cell DAC. £1700
Stellar S300 Stereo Power Amplifier – 140 wpc/8 ohms; 300 wpc 8 ohms. £1500
Stellar M700 Mono Power Amplifiers – 350 wpc/8 ohms; 700 wpc/4 ohms. £3000 the pair

PS Audio website

Stellar Gain Cell DAC
Stellar Gain Cell DAC
Stellar S300 Stereo Power Amplifier
Stellar S300 Stereo Power Amplifier
Stellar M700 Mono Power Amplifiers
Stellar M700 Mono Power Amplifiers

We like valve amplifiers, and have considerable experience of the different types that are, and have been, available.

Designs of valve amplifiers fall into three basic principles: single-ended, push-pull and output transformerless (OTL). Push-pull designs are the most common as they can be designed easily to give as much power as required dependent on the number of push-pull pairs of valves utilised. Because of this, this design works well with most real world loudspeakers on the market. Single-ended designs inevitably mean low power output, but can produce superb results with appropriately sensitive speakers, but good examples of these are hard to find. OTL designs can combine the transparency of single-ended with the dynamics of push-pull, but there are only a few designs based on this principle.

There are many valve amplifiers on the market but not many that sound truly excellent. Those that do tend to be very expensive, possibly too highly price for what they offer. We continue to evaluate brands as they appear and will only select from those that satisfy our criteria on sound, value and reliability.

At present we are considering two OTL designs classic designs with completely modern interpretations. One brand from Germany called Eternal Arts with amplifiers delivering extremely wide bandwidth, powerful, but with a low noise floor. The other is from Italy called Alieno LTD 250: a Class A. OTL and OCL design generating 250 wpc from just two 300B valves. Seems unbelievable on paper but, from hearing a pre-production sample in a very high quality system, the sound was truly excellent substantiating the claims.