POWER AMPLIFIER ACCUPHASE A-45 WOJCIECH PACUŁA Translation: Krzysztof Kalinkowski

Some time ago, a wave of discussion swept through American Internet forums, if Sam Telling, a pillar of “Stereophile”, does not exaggerate with testing of Musical Fidelity products. Every second or third issue of the magazine, in his column, a review of next box of the, otherwise very renowned, British company. The question was repeated many times in letters sent to the magazine. Telling replied that he will do it as long as Musical Fidelity will produce so good and well priced products. Point. Then, next month, when he had no MF device handy, he presented ... a watch of this company.

In case of the A-45 the case takes on another context – because I borrowed it thinking, that it might be good enough to be left as reference in my system. Much bigger, more solid and powerful (by 50%) than the ingenious model A-30 of this company (test HERE), that earned the Product of the year 2006 award (HERE), seemed to be exactly that what I was looking for. Reliability, current stability, efficiency, class A – all this is offered by the A-45. Actually, in many aspects, the A-30 was sufficient, but the thing it was lacking to be able to partner products from around 50000zł and more, was resolution. This one feature I expected to get in the A-45, and I was not mistaken. Even more – I got everything I could dream of at the price only 2 times higher than A-30 and with this 2 times lower than the top A-60. But I did not keep the amplifier. Why? Just read on.

LISTENING EXPERIENCE

If you read my test of the A-30 model, you will know that I liked it very much – this small, working in Class A device is really under priced, and with a good player with variable output it is able to produce beautiful sound. A problem in its case is transparency and coming out of this the problem with preamplifiers – for this money only few devices can do justice to it, and none will exploit fully its possibilities. That is the reason that the Lektor V from Ancient Audio turned out to be a very good match (test HERE), although it lacks balanced outputs (and in this mode the Accuphase amplifiers perform best) it still proposed a very good compromise between integrating an preamplifier and just RCA outputs. Some time later I found the ideal match: A-30 and the split player from Cyrus – CD XT + DAC XP (test in this issue of HFOL) – here is a solid preamp and balanced outputs. Of course it sounded splendid in combination with my AA Prime (test HERE), but the price twice higher than that of the amplifier makes this combination quite unlikely. So the A-45 seemed to be the ideal candidate for the Prime. And ... nope, it didn't click.

A-45 is a completely different amp than the A-30. It is much closer to the A-60 than to the younger brother. This is a true high-end, almost completely transparent amplifier, with impressive dynamics and an incredible bass control. Please do not be fooled by the catalog data, especially the nominal power output, encoded in its name, stating that this amplifier reaches 45W at 8Ω. With the impedance going down by power of two the output power increases by that amount reaching a whopping 360W at 1Ω (for music signal). If this is not enough for somebody the device can be bridged and then it reaches 720W at 2Ω. Hmm, impressive... And this all playing in Class A. Owing to that and the incredibly low noise (the broad frequency range does not interfere with anything) the sound is almost deprived from its own character, almost everything what can be heard is the influence of devices placed before or after it in the chain. Maybe it is not yet the level of the Halcro dm38 (test HERE), but it is really close to that, and that with a better punch on the bass. So there should be no deliberating, but one should just have just got it, yes? Not quite. It appeared that the A-45 did completely not play without an external, active preamplifier – all players: the mentioned Cyrus, Cary CD 300/303, AA Prime, Wadia 27ix converter (test in next issue, #25, devoted solely to American devices) or the split perfection – Accuphase DP-800/DC-801 did not become friends with the tested power amplifier when the latter was fed from the variable output of those. The sound changed according to the used source, the differences were shown very clearly – the resolution of the A-45 is breath taking – the transmission was top notch, but in I did not get the creeps as with the A-30, I did not shuffle my discs to get more Music from them. Because the sound was ideally neutral, but was, to a large extent, lacking emotions, that should accompany the sound itself.

The solution was an active preamplifier. The best companion was the Accuphase C-2810. And this is the whole problem – this preamp costs 49900zł! This is almost two times the price of the power amp! I cannot afford that, and I will not be able to afford that anytime soon, even taking into account the press rebate (something that is common in the whole world). But if somebody has the spare change, and is able to add Prime to it or the mentioned split Accuphase SACD player, this is the right quality level. The A-45 can always be replaced by the A-60 model, but it costs twice as much, the sound is only slightly better, and in addition we have the much larger dimensions of the top Accu power amp. If this is a non issue, then you can go for the A-60, because this is the same kind of sensitivity to sound as the A-45, but I, frankly speaking, did not feel the need to do so myself. Having the money I would rather opt for two A-45 in bi-amping system. Because I would rather not put Accuphase in bridged mode. I heard it a few times, with different power amplifiers of this company, and I can openly say, that in this case bridging is an inferior solution to bi-amping.

So we can go now to the sound itself. A-45 with the P-2810 sounds incredibly coherent and precise. These two -seemingly – self excluding categories go here hand in hand. When the first tact of the acapella sung, with a distorted voice, first part of the title song from the King Crimson disc The Power To Believe (Sanctuary Records, SANCD155, CD) make the hair (or fuzz – depending on how the Nature treated the listener, and how often the hairdresser is visited...) rise on the neck – literally! Because there is detail and emotion in the sound. The sound of the A-45 is neutral and precise, but not washed from emotion, that manifest themselves among others with dense midrange and saturated planes. And although it is Class A and in the “community” the stereotype of “warmth and euphony” is quite common, here the amplifier is much more neutral and transparent than the working in A/B Class power amplifiers P-3000 (test HERE) or P-5000 of this manufacturer. Adding a preamplifier adds a bit of sweetness to the sound, but most of all it frees the sound from the mechanical accuracy and replaces it with reality. The brass, although only on the surface, become in a way polished, cleaned, to make them shine more. This does not change the basic sound. Also the other side of the frequency spectrum is incredibly neutral – the bass has a quick, short attack and comparably quick decay. But this sustain... Thick, saturated, strong, as if there would be 500W of tubes under the hood. Though the whole is rather agile and resilient. This has to be watched, when choosing appropriate speakers, that should not be too dry and thin. Because the A-45 has nothing in common with tube devices (maybe except the 300B tube based SET Grand Mono amplifiers from Ancient Audio, that it resembles in many ways, maybe not reaching the level of absolute transparency, but surpasses them in the quality of the lower registers).

In its striving to the truth Accuphase draws studio devices to mind, but in the good meaning of that statement, it is not about brightening. It is not here. It is more the strive to achieve the absolute truth at any price, even leaving dead bodies in the dust. That is the reason it will not appeal to everybody. The Beatles from the disc Love (Apple/EMI 379810, DVD-A 24/96/CD) sounded very true and “modern” in the meaning of not cutting the frequency range and without the “boxy” sound stage. Their voices, similar to the voices from my reference disc in that matter Five Songbirds (First Impression Music, FIM89 DV, HDCD24) had a very clear articulation, timbre, etc. They were maybe not as pleasant as from my Leben paired with the Jadis (tests HERE and HERE respectively), but for sure they were more precise and, probably, had better shown small details. In this case they were more neutral than natural. But some of the guilt is to be blamed on the Prime, that I prefer to the Jadis.

The sound stage of the Accu amplifier is very neat. Similar as precise are the timbres, the placement of the musicians is clear and unambiguous. Changes in the mix of the pieces on the FIM disc were very clear, but not to wonder about them, but to reproduce the character of every recording even better. The A-45 has not a very broad “gesture”, and as within the window marked by the speakers (in this case the Harpia Acoustics Marcus – test HERE - and the KEF Reference 205/2) everything is perfectly placed, both in the horizontal plane as well as in depth, not much happens on the sides. However the window itself opens almost to infinity. Thanks to the incredibly helpful in that case Prime in “The Beat Goes On” from the mentioned disc FIM, a piece by Patricia Barber, the inside of the club was just behind my room's back wall,it was filled with the air “fluid”, the cigarette fumes could almost be smelled. With recordings like “Not Too Late” from the Norah Jones disc (Blue Note/EMI 382035, CCD), a bit manipulated and tuned, and due to that not fully transparent, there was no such breath. But this is just how this disc was recorded... Also here the bass control was above average – this is real BASS, that can physically hit with good speakers.

And as it happens in life, and in the life of an audiophile quite often – something good has not always to be better than the worse thing... This is a paradox, but also a truth. If I find somewhere a balanced preamp (active) at a reasonable price, then I probably return to the A-45. At this moment it is out of my reach, as it costs 80000zł with the P-2810. And to the presence of Accu in my tests: cheer up – there is not much left in the portfolio of the company for me to test, so I will have to look for something else at this price/performance level, equally solidly designed and built, and most of all – available. At this moment I still have in testing the split player DP800/DC801, split amplifier C-2810/P-7100, tuner T-1000 and the DP-500 player. That's it. As there are quite a lot of devices that were tested to date, so we plan to put all those together and publish as a “Special Issue – ACCUPHASE”, with a separate cover, lead article, etc. Similar as in discs “The best...” we will add a new article – a relation from the Krakow Sonic Society meeting, during which we will compare three incredible products of this manufacturer – split players: DP-90/DC-91 + DP-100/DC-101 + DP-800/DC-801. We want to have a closer look at how the taste of Japanese engineers changed in the course of time, and if the switch to sigma-delta converters and to SACD platform was a step in the right direction...

THE MAKE

Accuphase A-45 is a classic, stereo power amplifier, with a balanced path from input to output, that can be bridged to achieve double output power. This is a large box filled with electronics, with large VU meters in the front panel (as Radek Łabanowski tested in Audio while measuring the integrated amps, Accu VU meters are very accurate) and large rounded heat sinks on the sides. Those are needed, as the device operates in Class A and gets heavily warm. We have XLR and RCA inputs at our disposal, large, gold plated speaker terminals, and on the front panel a switch for amplification level -3/ -6/ -12dB, which is not a simple resistor splitter but part of the active input buffer. This part is placed on a small supportive PCB. The power amps are built-up on large PCBs with gold plated tracings, screwed directly to the heat sinks. This whole part is transistor based: working in cascade setting bipolars in the driver and MOS-FETs from Toshiba (K3497+J618) in the output. Six of the latter pairs are used per channel. The input and driver use many more elements, because – typical for Accu – the signal flows in many parallel identical branches (this solution is called MCS+: Multiple Circuit Summing) and is here to minimize the noise and distortion. Interestingly, another constant Accu feature is the usage of inexpensive elements – we will not find any polypropylenes, expensive resistors or similar. The engineers of this company say, that better effects can be achieved with precise selection of easily available elements, that is not cheaper than buying expensive elements, but not selected. I will not argue with that, because the results speak for themselves. In the middle a toroidal transformer is placed, with 600W output power, shielded, with two partnering Nichicon capacitors with Accuphase logo (2x47000μF). From the transformer many secondary windings are protruding – for every channel separate, for the power amplifier as well as for the preamplifier stages. The latter received dedicated, precise rectifying circuits. To stabilize the parameters of the amp a feedback loop was added, but it is small and done in the current domain, so phase shifts could be avoided.

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