Review in AUDIO magazine (Germany), August 2004
Accuphase Class-A Power Amplifier A-60

Up please!
by Joachim Pfeiffer

Since generations amps from Accuphase have always remained true to their visualappearance and from a sonic point of view have become better and better over the time,
though, to this date, in small steps only. What follows now is a quantum leap.
Why a power amp like the new A-60 from Accuphase? Let's ask someone who should
know, namely AUDIO's speaker tester Knut Isberner. It's because hardly anyone else could
gain as much experience with the predecessor model A-50V from the same maker. For him
the "50V" is simply the best choice when it comes to driving his own, highly critical Infinity
Kappa-9 speakers (yes, I do mean those aged amp-killers…). The efficiency of the "9" iscertainly not a good one, yet in some way acceptable. What makes the Kappa the enemy ofnearly all amplifiers is their impedance curve in the so-called "extended position" which has
always been preferred by my colleague. In this position the speaker impedance drops way
down to the extreme value of around 0.78 Ohm in the ultra-critical bass region.
For this reason any power amplifier that is to be hooked up to the Kappa should be
able to provide an ultra-stable, perfect voltage-impedance cube (see lab report on page 128)
without any sign of collapsing at whatever spot. Otherwise the speaker divas are going crazywhile quite a few of those little amps are waving "good-bye" and, in the worst case, go up insmoke. It's not really sensational that the A-50V is driving this Infinity-legend without flaws.
Other amps with a similar price tag can do that also - and quite laid-back nevertheless. What
made the A-50V so fascinating to Knut Isberner was not what it was capable of doing, but
how it eventually performed. Smooth, consistent and with an unusual differentiated renditionof sonic colours did this combination conquer Isberner's listening room and thus hisaudiophile heart as well. This may well be due to the fact that the A-50V, its predecessor
A-50 and now the successor A-60 sweat away in Class-A mode of operation.
Big power meaning lots of glory?
This mode is certainly favoured by audio connoisseurs as well as the board of directors ofyour local electricity company. Maximum bias is a principle here and duly requested to takecare of low distortions. Or in other, somewhat more technical words: because of the amountof current that is continuously flowing through a semi-conductor the latter can always operate
in the optimum range of its characteristic curve.
So, what's new and how are A-50V and A-60 distinguishing themselves with respect
to handling and technology? Actually, the power stage is nearly identical with the exceptionthat in 2004 new power MOS-FETs are shining from the two meticulously equipped circuitboards. The circuitry itself has not been changed. What is indeed new is the input stage which
Accuphase have dubbed MCS: Multiple Circuit Summing. This means that three separate1amplifiers for the input signal are connected in parallel in order to downsize noise anddistortion to another record level.
One thing is for sure, namely that all these measures have nothing to do with saving
money on the side of Accuphase, although one could have this idea as the amp comes a fewhundred Euros less expensive than the A-50V, but this may be owed to the presently better
position of the Euro against the Yen.
No "saving money" can also be recognized by the more or less relevant details,
whereby a new conception can be noticed on the board for the speaker terminals, yet not fromoutside, although number 60 now does accept banana plugs too. The positive changes arerather to be discovered inside the unit. In order to achieve a more careful and pure signaltransfer to the terminals the respective circuit board has been designed substantially moreelaborate. This feeling of "getting more for the money" continues if one looks at the featuresof comfort. In particular the gain selector at the front panel -for attenuating the gain factor by
3, 6 or 12dB- makes a lot of sense indeed. Especially for all those dedicated hi-fi aficionados
who wish to employ this Class-A amp exclusively for the treble and midrange and a mighty
high-power booster for the basses. Nevertheless, such a quite acceptable configuration has
been reasonably feasible only with a blend of Accuphase's own power amps. Now, with thelaunch of the A-60, this one-brand-purity-law has eventually become history. The amp'sflexibility ensures a good sonic marriage with other foreign amps - as long as theiramplification factor is compatible.
Then we find a little button at the front panel which we believe is not really necessary
at this place. By pressing this button the A-60 switches from "unbalanced" to "balanced"
mode of operation, meaning from RCA to XLR (inputs). Another innovation has absolutely
nothing to do with acoustics. As opposed to Accuphase's P- and M-series of amplifiers (allworking in Class-AB mode of operation) which are showing off their power by means ofover-dimensioned meters, the A-series, including the new A-60, has been equipped with anumeric display. It is assumed that most users are going to switch it off, because arhythmically dancing meter indicator may be a joy to look at, but certainly not the figures of adigital readout. Hence it's good to see that something has come back with the A-60, i.e.
something that has been banned from the hi-fi world for years. Namely two LED bar graphindicators which can optionally be made to flash in concordance with the music. This you
wouldn't want to be deactivated, would you?
The listening test took us an unusually long time. Not that the scoring had given us
some headaches. No, this was more due to the fact that my colleagues from the AUDIO teamsimply couldn't get enough from the music playing through this amp. One CD should beparticularly mentioned here, yet it's one that cannot be acquired from a main street CD shop.
"Try A New Way" is the title of this disc and it's running time is a mere 21 minutes. Playedon a Steinway Grand by Martin Vatter, the music on this CD is ingeniously composed as wellas superbly recorded and produced (available through www.martin-vatter.de). Via our top
notch audio chain in which the A-60 is playing the central role, it becomes immediately
evident that this sound carrier has hardly any audible digital cuts. A tone and its multiple
harmonics are simply better joined together than on most other silver discs and thus aresupporting the flow of the music.

2This Accuphase-amp can definitely show it all, and more so can convey the size of theSteinway and its uniqueness of sound colours. The A-60 can render the musician's incredible
pleasure for making this music and it can yield much more than you'd ever expect.
Considering its capability of pleasing the listener with the rendition of music as a whole, theA-60 is, at this time, the most reasonable offer in the league of the best. If it could havegenerated a tad more control in the bass region, it sure would have become our top reference
power amplifier….
SUMMING UP:
It really knocks me off: with the A-60 Accuphase Laboratory Inc. are probably building thebest pure-bred Class-A amplifier of the present time and with it may face a strong competitor
under the same roof. The more than twice as expensive monos M-8000 are outdistanced by
the small heat power station in several aspects: the latter is better in reproducing voices andmoods and in no way does it sound like hi-fi. More so, it sounds 100% like real music. Morefun with basses I have when I listen to the M-8000 and, no question, this one can play atmuch higher levels. But that's about it and hence I do consider the A-60 the better choice.

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