Digital amp beat them all? Audio Physic Strada .


The german magazine Stereoplay has(in its June issue) a review of the new Audio Physic Strada monoblocks.
Like most german audio magazines this has also a preferance for ranking products in a hierarcic manner.
Interestinly, the new monoblocks from Audio Physic gets
60 point (on a scale that end with 63 points), while the
mag´s former reference Krell FPB 650 M gets 59 p.
For your knowledge;Electrocompaniet Nemo gets 58 p, the same as Pass X-350.
Althought the fact that I am sceptical about ranking systems
in Audio,I find it remarkable that a digital amp allready
can compete with some of (what is regarded) as "top-flight"
amps!
The Strada monoblocks has a switched powersupply and some
innovative curcuitry,e.g. it seems to be handling signals
of low amplitude in analog way, and switches over to digital mode for higher amplitudes in some form of bridge
output section. Sorry, my understanding of technical german
isn´t splendid.
They deliver 255 W/each in 8 Ohms, and costs about 15000 Euro a pair.
What do you think? Are digital amps taking over the scene
in the years to come, or will there be a "resistance movement" corresponding to that of CD-anlog?
dinos
I'm not talking of 8Hz as the freequency reproduced on the same level as all 20Hz...20KHz audiable freequencies. I'm talking of 8Hz harmonical components of an audiable freequencies that can go upto 52KHz. They're signifying the tembre of a particular voice and instrument. Making the sound of tum or drum 3d and more real(for a small example). Analogue playback starts from mechanical transfer that has no limit to the freequencies whatsoever.
Whenever it's 8Hz or 32kHz it's all there in the stylus in the first place...
Shortly saying we've got two ways to create imaging: one way is to get as full range as possible capturing all the sub and over-harmonics or with current digital limitations we should create a digital immulator of 3D space by micro-phase shift(s) of a different channels according to the room dimensions or whatsoever(when you will get a chance to deal with TACT you'll know better).
The first analogue way creates a natural(or at least as closed to) and the other way creates pseudo-imaging.
I've clearly stated what I've heard from the same source with different setups before that the placement of instrument/musicians was different but although more clear in the sound stage. Thus from that I'm making my conclusion here. I've actually expected TACT to do some magic, but was dissapointed for the price you'll have to spend for that unit vs. more valuable analoge options.
Once again to say I've "factored" it out leaving 1 in numerator and analogue in denumerator.
Actually I was being kind of mean. The specifications are from the Yamaha RX-V2200 A/V Receiver.

I hoped to make a point that specifications are pretty much meaningless, we must all take the time to listen with our ears and our hearts and quit being influenced by the data.
I agree to that Albert, most measurments (on amps)doesn´t tell us much about how the amp actually sounds.Some well- reviewed amps that I have read about recently, have rather high figures of intermodulation distortion.Probably, the usual,static measurments miss important information of an amps behavior under more realistic, transient signal conditions.But some measurments, e.g. an amps delivery of power into a reactive load, tells us somthing about the amps ability to drive real world loads, i.e. speakers.
Stereoplay has an interesting hypotesis that valve amps and digital amps have one thing in common, namely that they are less prone to be affected by back-EMF sent (back) from the speakers to the
amp(s).And perhapes they can be made,so that they pollute
the mains less than conventional amps?

If digital amps can compete in the High-end sector, only time will tell.But I find a big advantage in their superior efficiency! That is less disturbing to the environment,and
at the same time save us from some heat! (I have to admit,
that I now use a big class A amp.)My own belief, is that
we will see digital amps taking over the scene sooner that
many of us expected.Like all predictions, it can be wrong.
I live in Germany and read most of the commercial German audio press. For those of you unfamiliar with these magazines, they focus on different "target markets": low to middle class hifi (Stereoplay, Stereo, Audio), high-end (Audiophile, Image HiFi). Although they are primarily marketing devices for German audio manufacturers and distributors, these magazines do occasionally review unusual components outside the German market and have the advantage of publishing technical data, specifications, and photos of the circuitry.
Although I am generalizing and my German audio friends will hate me for this, German high-end enthusiasts tend to like a very "analytic," rational sound from a component "built like a tank" ("wie ein Panzer gebaut," a cliche one hears over and over in German circles), with solid, dependable workmanship. In amplifiers, they tend to like high-power, solid-state designs, to drive very inefficient, large speaker systems (the most important part of an audio system in Germany is nearly always "die Boxen"). There are exceptions to this rule (a relatively large interest in tube amplification, SET, retro, etc. and there are some exceptional small German tube amplifier manufacturers that you will never hear about in the USA), but this is the general rule.
I mention all this, to provide you with the context for this review of the AudioPhysic Strada--a digital power amp coming from a large, well-known German manufacturer of relatively inefficient speakers, with a lot of capital tied up in the press. On the face of it, I can think of no better magazine for the Strada to be reviewed than Stereoplay or Stereo. Both magazines have been ranking digital preamp and amp products very high in the last few years (I am thinking of TACT Millenium review, Sharp review, and the reviews of Accuphase, TAG McLaren, Z-Systems digital amp / pre-amo products as well the praise lauded on the Gryphon Callisto 2200--an entirely OpAmp design, which is usually considered the #1 integrated amp by these magazines, 100% Klang-Qualität, as they put it.)
Despite all this, who can answer this simple question: Why haven't alot of manufacturers (besides Sharp, Tact, AudioPhysic, and a few others) brought out digital amplifiers, although the microchips for these have already been around for a long time? Looking at the specifications (which albert potter is right to point out as "pretty much meaningless"), why don't alot of manufacturers produce digital amplifiers?
Well, because the resultant interferencee from the digital coupling signals on other pieces of equipment is so high that in tandem with a complete system, one can no longer speak of high-end audio with digital amplifiers. With a typical digital amplifier, a digital coupling signal of at least 1 volt dances on the loudspeaker cables, with lots of power, and possible interference. The interference frequencies (even filtered with multiple capacitor networks) are often over 1 MHz in 3 Volt region, and many harmonics come on top of that. The portion of the interference that is reflected onto the mains results in large AC interferences that cannot be completely eliminated. Also the interference that is sent to other components are incalculable. And think of the following: one can isolate the sampling signals of a CD player from the mains by using a mains filter or isolation transformer or power gnerator, so that other equipment will not be loaded with it. This is measurable and controllable. The interference from a digital power amp has a power and reaches a value that makes rectification almost impossible. It is much higher than a CD player. EMV problems that are trully unsolvable result. The extent of interferejce is so high that all benefits, like higher efficiency annd lower distortion, are meaninglless and the succes--from a high-end standpoint--is entirely questionable.
Dinos, I agree with you, digital amps will be much more common sooner rather latter. No, I don't think they will replace the majority of the amps out there right away. Many manufacturers and dealers are loath to invest large sums of money on R&D and marketing that might risk an established customer base. Why should they? Perhaps to avoid being left behind and loose there share of the customer base? Unfortunately many can not forgive the hype of "perfect sound forever" and carry a strong aversion to anything digital. In my limited auditions of digital amps I found them more in common with tubes than solid state. They exhibited a liquidity that tubes are known for. They presented the solid bass without the "electronic off flavoring" sometimes found on some solid state amps (especially on the "silent" parts). I think it's the upper end that is going to divide many listeners. I find them to be accurate and extended, other who have been with me at the same auditions found them "bright". I for one am excited by the promise of digital. I don't think we can go much further with current technologies. Whether digital amps are a step forwards,backwards or sideways, only time will tell. I'm optimistic that it will forward us into a better "audio" future.