Technics SU-R1000 - Good but not the king of switching amps
Was looking at the measurements for the Technics SU-R1000 Integrated published by Stereophile. I never bother with the reviews of the sound quality as there’s 1 reviewer there whose ears I trust and it’s not this reviewer.
To be clear, this IS a digital amplifier, and is not a Class D amplifier. Atmasphere will always disagree with me, but given Technics nomenclature and the use of an A/D converter, and PWM output I think if any amplifier qualifies as digital this one does.
What I find kind of interesting here is that the measurements are OK but not absolute Class D killing results. I am particularly unimpressed by the performance of the impedance compensation circuit, LAPC, which at the end of the day does not seem to have performed significantly better than actual, non GaNFET amplifiers, particularly in removing the effects of the output filters Class D amps require. I really hoped to see a huge win here... but it’s not. It’s just making the PWM perform almost as good as a true Class D amplifier.
I have not heard this integrated, but the claims and expectations laid out for the technology seem to not be proven in the measurements. This is a very expensive integrated that does everything differently, and measures about the same as previous generation, also excellent sounding, Class D engines I’ve seen measured.
My stance that Class D was already very good and that new, faster switching amps would have to be truly spectacularly better to unseat them remains, in my mind, uncontested.
Can’t wait to see everyone trashing Class D on the measurements suddenly decide that this amp should be heard and not measured.
There have been plenty of great switching amps before the Technics, and there will be more long after, so I'm not really surprised listeners like it. :)
I'm more curious about all the technical expectations which IMHO haven't really been met here. It was expected the extremely elevated switching speed would raise the performance for switching amps. It seems, based on measurements, it's not better, just as good. |
@erik_squires I think most of that came from the George guy who used to post here quite a lot until recently. Personally I can't think of a good reason to switch at such a high frequency and I can think of plenty of good reasons to switch at a lower frequency. If you were trying to get a lot of loop gain, switching that high might be an advantage, but that doesn't seem to be what they are up to. One thing that is problematic is dead time- that is a fixed value for a particular output device. The faster you switch, the greater the percentage of the total time winds up being dead time; a slower switching speed can allow for lower distortion. |
Yes, this is true, but it’s also true that these amps do have a lot of innovation in them. VERY different technical solutions to technical issues around Class D. I was actually really hoping to see these amps just be stellar technical performers, like Halcro of Analog. I also completely agree that the real proof of a technology is in the listening. :) |
@erik_squires Yes, it seems as if the speaker correction thing is a sort of feedback system of its own. But it shouldn't have to be something just for class D. I've been trying to sort out if you even need something like that- audiophiles haven't for decades. |
