There is no 'right way' to get good sound, absolutely brilliant speakers may do enough, in enough areas, to sufficiently compensate for lackings elsewhere, for the majority of recordings that a particular person listens to.
I see the process of optimisation as achieving enough points to get the 'good stuff' - a magical 100 points, say. Getting rid of each weakness adds more points to the tally, but only getting 98 ain't good enough, it's 100 points or nuttin' - 98 could be extremely unpleasant, glaring sound, unlistenable to, in one particular scenario, say.
Of course, you can get 100 points with still many problems or issues as part of the package - which means that one can go well beyond that figure of merit. In my dabblings so far, I've had momentary bursts of going well beyond the 100, when the sound becomes - and this is the right word for it - staggeringly good. But this only happens when absolutely everything is in the best alignment, for what one is using at the time - but it demonstrates what's possible if the right efforts are made.
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I did not like the sound of the Mac, funny you know you can live with it based on what ..? and no I have not tried the JC-1 , so no comment. Also noteworthy how you glossed over the amp (Mac)shutting down on the test bench, twice .
Have you heard any of them ...? the overheating issue would be a big problem for me ...
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It apparently wasn't an issue for the reviewer, who didn't report any shutdown when playing music. That's why we buy hifi amps, right?
The anecdote in the Parasound review about the flawed grounding scheme getting fixed by Stuart Taylor of Bryston was amusing.
I doubt that the Mac's distortion measurement would show the similar shaped curve as in the other amp's measurement. IIRC, with crossover distortion present, distortion should be higher at lower output levels.
Since distortion is buried in the noise floor in this particular case, we do not know how the curve would look, therefore let's call those magazine measurements meaningless and, probably, close the topic.
Best,
P.S. Low absolute THD numbers TO ME are indication of heavy use of NFB.
So you think the Mac guys didn't figure out the trick where you run an amp in class A at low power levels?
Gentlemen, I will not be lured into criticizing a competitor's product when I did not even know of its existence until SY put it up for comparison. I did wish to point out what I personally use to evaluate what I 'think' an amplifier will sound like from certain aspects of the measurements. NO AMP IS PERFECT. It is a matter of 'trade offs'. More heatsink is also more weight and space (and extra cost). However it does allow higher quiescent current to be present all day long. This, in return, lowers the rate of curvature of the open loop output transfer function, which then lowers or effectively removes the higher order distortion artifacts. IC's can have this problem also, especially the low quiescent current grades. It is just an engineering tradeoff.
...the comments from the boutique Audio guys are now conveniently ok
They can be trusted to notice if the amp shuts down when they use it for music. That's what I use my amps for. If you prefer use your amps for test bench purposes or heating resistors, that's your business and there's some excellent choices out there for those applications.
Dithyrambic prose and high ratings from Stereophile chimps is John's "listening contest" criterion, not mine.
Nothing posted allows us to make that assumption. We're all guilty of assuming a monotonicity that real amplifiers don't have. The mechanism that causes crossover distortion is especially non-monotonic, and even its inverse.
As I and PMA have suggested, tests should really be made at 0dBW and +10dBW as a bare minimum for usefulness. -10dBW and -20dBW would contribute very significant information.
And, as John Curl has tried twice to make us accept, extrapolating from the given tests at +25dBW is foolish at best. The most useful part of the given tests is the picture of the distortion component vs. time, fig 8 IIRC.
Thanks, as always,
Chris
Apparently not. This measurement shows gross crossover distortion at less than 200mW output.
Attachments
I agree. It is ugly.
To hell with gm doubling - I always over bias so the first 0.5 to one watt in an AB is class A. And I'll do more if the heatsinks allow it.
(In Knysna BTW - two days of fabulous weather. Sitting on the inlaws stope drinking 'koffie')
McIntosh MC501 monoblock power amplifier Measurements | Stereophile.com
Fig.8 McIntosh MC501, 4 ohm tap, 1kHz waveform at 480W into 4 ohms (top), 0.00075% THD+N; distortion and noise waveform with fundamental notched out (bottom, not to scale).
Measured at 480W, not 200mW
P.S.: their job is admirable, especially when we take into account they use output transformer!!!
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