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Arcam A49 AmplifierWithin the last couple of years, Arcam has been beavering away at a brand new range of amplifiers. I had been told by an insider in the Cambridge-based firm the brief was to create the "finest-sounding amps" it could, with cost a "secondary consideration". They may be thus really 'state of the Arcam', to the extent the guy responsible for his or her design - firm founder John Dawson - has been 'immortalised' by having his signature silk screened onto one of the integrated amp's circuit boards. You can find three products in the US-built '49' set - the aforementioned integrated amp, a power amp and a preamp. Examined here. The latter two are authentic solid state power stations (200 watts into 8 ohms, courtesy of paralleled output signal-transistors and an enormous toroidal power transformer) and reap the benefits of an amplification technology called 'Class G'. Here, the negative and positive DC power-supply trains that furnish the bipolar output phase of a traditional Class AB amplifier are instantaneously 'lifted' (from -/+ 35V to -/+ 65V) when needed. This 'train-substitution' process is maintained to combine energy-saving efficiency with effortless power delivery on occasion of demand (for example dynamic fortissimo passages at high listening levels).
Although Class G was comprehended in theoretical terms for a while, it has just become a practical reality with all the development and sensible enactment of new MOSFET devices in circuitry able to 'follow' the audio signal and, as needed, switch in copious amounts of DC power at sub-microsecond speeds.
And that's where the R&D efforts came of Arcam into their own. Class G was initially shown in recent Arcam station AV receivers; the '49s' are, nevertheless, its first'pure' stereo products to gain from such thinking.
Targets that have been fulfilled include the virtual removal of crossover and complete harmonic distortions, the capacity to drive difficult loads (down to 2 ohms), DC-coupling throughout (Arcam believes that capacitors in the signal path launch audible colouration) and the banishment of sound and channel mismatches through cautious part selection, earthing and circuitry layout.
At lower listening levels (below 50W - with most modern loudspeakers, you will seldom need to go above this in typical British rooms) the A49 functions in Class A, thanks to biasing circuitry of proprietary layout.
The preamp has its power supply with different transformer. It includes a clever microprocessor-controlled, solid-state source-substitution system, and a signal attenuator (volume/balance control) based around chips with integral resistor ladders. The benefits of ridding the A49 of mechanical switches and potentiometers that are conventional comprise improved long-term dependability and independence from 'contact sound'. Arcam have even bestowed the A49 with the independent headphone amplifier!
There's plenty going on as regards connectivity. The A49 has a low-noise MM phono stage (based around audiophile op-amps), a balanced input and no fewer than six line-level feeds - if it's not desired, the phono input can be transformed into a seventh line-level one.
Also specified are preamp outputs (balanced and unbalanced) for additional amplification (should you require it!), 6V and 12V DC terminals for Arcam accessories and also a dedicated tape output that enables you to record the selected source. Regrettably, the A49 lacks a certain tape input signal (and the associated 'computer screen' facility) so that you will not be able to hear what you have only recorded - unless you use one of the line input signals, and risk creating an enormous positive feedback-loop if you accidentally select the wrong one with your recorder in 'source computer screen' mode. Not a good idea for your loudspeakers (and ears), with all that power on tap!
Two pairs of independently-switchable speakers, interfaced to the A49 via substantial binding post/banana-plug receptacles, are catered for. The A49 is easy to configure and drive, courtesy of the front-panel controls or the supplied handset (which will also operate other Arcam supplies - players and tuners, for instance). As well as source and speaker choice, it'll let you adjust volume, mute and stereo equilibrium. No tone controls are on offer here, however an AV 'processor' mode (volume control disengaged) is available. A (dimmable) front-panel screen affirms chosen input, volume level and functional status.
SOUND QUALITY
I partnered the A49 using a set of Quadral Aurum Wotan VIII loudspeakers - substantial floorstanders with ribbon tweeters that were showing. single of Information Society's What's On Your Own Mind (Pure Energy), one of these amazing electro-infused dance tracks from the late 1980s.
Wow! When most people speak about the Arcam sound, adjectives like 'safe', 'smooth' and 'laid-back' traditionally pop in their sentences. Not here; the electronic drums that give the track its rhythm bristle with energy, tautness and, well, snap. The glowing synths and upbeat vocals also come across nicely. In short, excitement abounds - although those Aurum tweeters are of apparent help here at higher extremes of frequency. I remember hearing the track's drum and synth bass reach a tad lower; afterwards, I discovered a really comprehensive briefing document prepared by Arcam in which it was revealed that the phono stage includes a high-pass filter with a -3dB point of 20Hz.
Their subsonic like from ruining speaker cones and it is there to prevent record warps, and isn't active on any of the line inputs.
That's never to say the A49's sensibly-limited lowest-end trip detracts from your enjoyment of vinyl. Switching to a 180g pressing of the Stateless of Mark Beazley, and the bass guitar components of tracks like Three Twenty Two are communicated with articulation and ample depth. This delightfully- minimalist album could have already been recorded by the Rothko bassist at home, but the A49 shows us that there's loads of atmosphere and musical detail to research.
Said record, master-recorded on 35mm magnetic film and nicely-pressed on the age's adequate phonograph record, comprises Lew Davies' musical arrangements of numerous standards. And it proved to be a thrilling listen, with a believable stereo picture (uncommon at that point in stereo's history) and a presentation that combined musicality with analytic penetration. It is easy to pick out the basswork of Bucky Pizzarelli or Doc Severinsen's trumpet, Tony Mottola's guitar.
Next to CDs - and Wendy Carlos' Sonic Seasoning, a protoambient work that must have confounded those more used to Carlos' Bach interpretations when it was launched in 1972. The 'Spring' piece comes with a thunderstorm, along with the A49 held on thanks to its utter reservations of power. Its Moog textures and harmonies keep their distinctiveness, and complement rather than compete together with the 'real-life' components.
Fairly more standard a listen was Unknown Soldier, a customarily-expanded piece from the persecuted Nigerian Afrobeat pioneer Fela Kuti. The metallic 'tang' of the sharp brasses, Kuti's keyboard and insistent conventional rhythms come together as a musically-cohesive whole which never loses its grip. And as soon as Kuti's female-backed lead sung starts in regards to a quarter of an hour to the track, it may be heard to crackle with a strong emotion that befits a composition dedicated to his mom (the 'Mother of Nigeria'), who was killed by the titular'unknown soldier'. That the A49 facilitates this type of connection does it justice as a little bit of duplication technology.
JUDGMENT
Yes, you feel a feeling of 'engagement' - and that's something that Arcam amps have not consistently provided in the past. Arcam reckons the A49 is the best integrated amp it is produced over 40-odd years of history. I can't disagree with that. It combines finesse with depth, focus and slam - all of which are underpinned by a musicality that is natural. |