The Yumcha Diaries: 03-10-09

The Yumcha Diary: 03-10-09
A question mark on digital amplification; and is the newer the better?

I. Digital Amplifiaction: it's efficient, but is it better than conventional methods?
First, a brief note on last week. After yumcha, three of us went to audition a new arrival in an old system. I have covered this system previously. Since the last visit, the short stand has been replaced by a single-pole Foundation 20", to good effect. The new arrival is the B&W N805 Signature, on loan from a friend, though without the matching stands. Everything else stays the same.

This is yet another instance when a change produces excitement at first, but puzzle on closer scrutiny. It was completely expected that the treble of the B&W would have a lot more sparkle than the resident large Chario bookshelves. With the 805S on the Foundations, there seemed to be a lot more air and a larger stage that generated excitement at first. However, closer attention reveals, despite the evident refinement, a certain lack of body that trivialized the difference between the upper and lower strings, and more seriously a relative flatness in the sound. Dynamics were not as they should be. We tried various placements (within reason) and experimented with toeing-in. Moving the speakers around did not help too much. Re-installing the Chario's brought back a fuller sound, better dynamics and balance overall.

I have always been a fan of B&W, and have listened to quite a few B&W Nautilus speakers including the popular N805 quite a few times. Every time, I heard an open sound and excellent treble, and this signature version is no exception. However, most of the time with the Nautilus series, the sound veers towards the polite and lean side of neutral, though never annoyingly so. Dynamically speaking, they seem to like being driven harder and played louder, seemingly to lose flesh at lower volume. Here I recall my experience with relax173's N804 driven by Graaf 20: the sound was relatively lean and flat driven by various preamps but came to life instantly after a Graaf preamp was used. So, the preamp and front-end is tremendously important (as always) if you want to move these cones. This time I begin to wonder about the dynamics of digital amplification, in this case TACT. The sound is beautifully smooth and not at all "digital" as some may assume, but I suspect they are not quite suitable for harder to drive speakers. We find we have to crank the volume up all the time to get a better swing. I cannot find much spec's on the S version, but the regular N805's impedance does not dip much below 4.8 ohms I read. I presume the impedance should not present much of a problem. Perhaps the large coils inside the corssover just consumes power. Chario's are likely not easy to drive either but I think they do better in this system. I hope one day I can borrow a digital amp and test it out in my system to answer the question. In researching this topic I note that there're actually few reviews of digital amps. Here is a TAS review on Lyngdorf's RoomPerfect digital correction/amp. BTW, we repeatedly found defeating the correction to be more natural in this system, though the difference is marginal (the host has a good room!). Here is a Soundstage review on the original TACT Millenium, which you may find interesting as it hints at dynamics, matching and impedance issues near the end of the article.

pic (click to enlarge) : sowk's setup. ARC galore. From top to bottom, LS5 MkI; LS5 MkIII, LS26; V70

II. The newer the better?
This Saturday is 中秋節, and a fine day indeed. After yumcha, three of us cramped into Captain's highly modified Subaru and sped in no time to his colleague Captain So's place in Sheung Shui, where we were joined by com-buddy, who lives in the same building.

Captain So is a really nice fellow and, like me, a fan of Audio Research ARC. Pictured is his balanced connected set of (silver colored) LS5 MkI + V70 amp, which he has owned for more than 10 years. The black one is his newly acquired LS5 MkIII and beneath is the LS26. For details of all these models, consult the ARC database. As sowk has graciously lent me his LS5 MkI I shall cover these preamps in more details in a future article. Here, I'd just like to add that the V70 is basically a Classic 60 with balanced input.

Source: Meridian 508-24
Speakers: Focus Audio 78

It would it be fair to say I have never heard a full set of ARC that I have not liked. I have known the LS5 + V70 setup for a long time. A close colleague bought a new set when they first came out and until he got married we had a lot of beer in his place, with this combo playing music! He is still using them winningly with his Sonus Faber Electa Amator I today, how's that for longevity? Needless to say, the combo here also brought out the best in the FA speakers, which is voiced a little too far from neutral for my usual taste, though always pleasant to listen to. Sweet vocals and no lack of power no matter how we cramped it up (we listen at much higher volume than sowk). Once again it proves the quality of a full ARC set. A smallish LR, but big sound!

The highlight was when we replaced the Mk I with the Mk III. Despite fewer tubes and less components the sound seemed to be a little more open and sweeter. sowk said the Mk III is very close to the Reference I in sound.

After that we paid a brief visit to com-buddy but had to leave soon. I also got the Meridian 800 transport from him to play with. Thanks Captain for taking me and my 2 new toys home. I understand on his way home he scared the shit out of a Lamborghini.

Watch for my detailed listening report on the ARC LS5 Mk I and Meridian 800.