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Try a $375 Crown 2500 (770 watts into 4 ohm). It only weighs 13b, so, if after a blind tasting, against a $2000 amp, you judge it negatively, you can return to Amazon at minimal cost. Big possible potential savings though...
Thank you! These are now down to $299 and there are only 18 left -- 17 now, since I bought one. It should be a great amp for my Tympani woofers, with the A-21 on the mid/tweeter panels. I'm skeptical of the highs on most Class D amps, but they're great for bass. Still, I'm curious, so I'll try swapping it with the A-21 to see how it does.They're so cheap I'm tempted to buy two and bridge them . . .
Bridging would be evil! Yes, the bass is great (controlled) due to characteristically high damping factor. I think that everything else is fine too, based on my ears. Measurements won't reveal the defects, that's for sure.
I've been reading through reviews and it looks like these really do have good sonics. I'm not planning to use them on the high end where Class D gets iffy, but it will be be interesting to compare them to the A-21.
Please, let me (us) know your thoughts, on the high end of these 'pro' D class amps. I'm old, and have much experience with dated, full class A and class A/B amps. And I tried couple of these with my Maggie 1.7s (not in the $2000 range; see previous post; http://www.audiocircle.com/index.php?topic=137402.msg1461666#msg1461666). Their highs were not superior, for me. Overheating and clipping were a problem, but they are, again, old, and may not be representative at all.The measured numbers however are on the side of class D. Objective testing, e.g. 'blinded' listening, is not a part of the 'audiophile' rating scale. It should be. 'Blind tasting' took California wines, in the 60s, from derision, to world class, overnight!
These cheap Class-D amps are what gives Class-D a bad name. Why compromise to save a few bucks? Ultra-high performance is only possible with experience and proper implementation. When Class-D is done RIGHT (very uncommon), the results are superior in many ways to other types of amps (Class-A/AB, tubes). Also, bench measurements can appear excellent with some newer Class-D amps, but this is done with gobs of negative feedback resulting in what I call ADCOM-ish Class-AB harshness. Just my 2-cents, but someone out there is likely to try and bite my head off because I speak my mind. Thanks for reading my post. (:
I suggest doing the 'blind' tasting, which has revealed, google it (age old argument, subjectivity versus objectivity), that 'golden ears' when thus challenged can't distinguish lamp cord from $100 a foot cable, or the cheapest receiver from high end preamp/amp. I'm a scientist, sorry, I'm into measurements and objectivity. And when humans are involved in a sensory (visual usually, or in this case auditory) rating, it has to be 'blinded', e.g. without knowledge of the decision maker of whether the specimen is the positive or negative control, or, in this case, expensive or inexpensive 'brand'.
I'm a big believer in blind testing (and so incidentally is Magnepan -- they won't put anything in their speakers until its been preferred by listening panels in a blind AB test, which I think is one of the reasons their new models are so reliably improvements over the old). And very aware of the research on confirmation bias -- Harman forex did a study in which subjects rated a cheap-looking speaker lower than an expensive looking one when they could see them, but not when they couldn't -- and this applied to every kind of listener, including audio engineers who were convinced that they were immune to such things!And then there's the story of the student who arranged an AB comparison between a tube amp and a transistor amp, and all the tube fans preferred the tube amp while the transistor fans preferred the transistor amp -- until a professor opened up the box and noted that the switch didn't actually do anything.Unfortunately, blind testing is kind of hard to carry out, I'd love to AB the two amps but that would require switching equipment that I don't have. So I typically use tricks to try to get around the subjective element, e.g., I'll ask people who don't know or care anything about audio what they think of an arrangement. Or I'll make my observations and then if the reviewer makes the same observation as they frequently do, it gives me confidence in my own.But often, I just don't know -- am I really hearing a difference, or is it just my confirmation bias?There are also limitations in the ABX switchbox. From a scientific perspective, it can demonstrate only one thing -- that a listener can observe a difference to a high degree of probability in a particular setup, or that he can't, *in that particular setup.* As with any experiment, there are numerous potential pitfalls, and while some experimenters are rigorous, many or not. So in general I find ABXing more useful for demonstrating that you *can* hear differences as demonstrating that you can't.One illustration of this kind of limitation -- a study was conducted to assess the audibility of a lossy audio encoding scheme. Subjects were unable to hear it. Then an expert listener was brought in, and immediately and reliably identified which was which, because with his trained ears, he was able to hone in on the flaw.Well, I could write a lot more on this but as I said I want to avoid that (already broke my promise, I guess). But I'd close with an observation which is that ABX testing usually *does* confirm that people can hear differences between equipment. Things that have been successfully ABX'd include sampling rate, power amps (subject to the conditions I mentioned), and op amps (as I recall correctly, the op amp in question didn't become audible until three are in series -- but it was common to have numerous op amps in the old analog recording consoles, and in the early days, some of them were seriously prone to slew limiting, e.g., the old 741).And I have heard stuff that just would not show up in a typical ABX test -- some of it quite obvious. To use a blatant example, my right computer speaker buzzes sometimes, *only* on piano music and only when it's loud. Someone who didn't know that could ABX my left and right computer speakers all day and never hear a difference. And I can think of other such phenomena in audio, none of them mysterioso -- forex, a power supply flaw in the old Hafler DH-200 (identified years ago by Walt Jung in The Audio Amateur), resonances in planar drivers that are only audible on certain notes.
