Is the above info outdated ?
Because weight almost always would indicate the amount of copper in the transformer and the mass of the heat sinks. Both indicators of quality.But remember: Weight seems to be the one measurable value of hi-fi audio gear that most of the »objectivists« in this field don’t feel like taking objectively
What is the THD at those measurements?
The Hypex are an interesting and high quality device...
www.audiosciencereview.com
The hypex ratings above (not sure about the others) are not based on PSU though, but on thermal performance. So it is not a case that the SMPS has short term higher rating like with a linear supply.The Hypex are an interesting and high quality device...
Details are here:
It's "Continuous Power" rating is only 50W/channel (with a note to make sure that you have good cooling/heatsinking!
There are no details of what load that 50W is into.
The "Max RMS" output power is rated at 1kHz, 1% THD - but it is not stated for how long (so not the standard power rating method) - 150W
Are we looking at the same device?
So we can try to get some sort of apples and apples comparison perhaps we should look at Amirm's test of an NC252 based amp?
Review and Measurements of IOM NCore Pro PWR Amp
This is a review and detailed measurements of the IOM NCore Pro, Hypex NC252MP class-d based stereo power amplifier. It was kindly purchased by a member and drop shipped to me. It costs €669 from the company website. The IOM Ncore Pro comes in very compact and solid enclosure: The on/off...
Continuous power measured
236W@4ohm
125W@8ohm
Peak power measured
277W@4ohm
146W@8ohm
So it has a bit of headroom, but not heaps
The Yamaha spec sheet is a much more traditional spec sheet, and (in theory) should be comparable to Amir's measurements.
Audioholics did a very similar test sequence (using much the same tools) at
Yamaha A-S801 Integrated Amplifier Review
The Yamaha A-S801 is an honestly rated 100 watt/ch integrated amplifier with a built in high resolution USB-B DAC to power a serious dedicated two-channel or upscale PC system with pristine fidelity.www.audioholics.com
Yamaha A-S801
Continuous Power
105W@8ohm
185W@4ohm
Peak (Dynamic) Power
165W@8ohm
295W@4ohm
Seems to me that the Class AB amp has more headroom than the ClassD - but in reality they are pretty much of a muchness...
Continuous 105W vs 125W is pretty similar - and peak 165W vs 146W is also pretty close (and unlikely to be any different in actual use!)- but you will note, that as I said earlier, although the (continuous) power rating is lower, the peak rating is indeed higher - so the ClassAB amp in this case, has more headroom than the ClassD - and would be the better option based on your criteria...
) it would be a continuous rating.I've always looked a bit askance at the way the cooling is done on most of these ClassD modules.... it does not bode well for long term reliability...The hypex ratings above (not sure about the others) are not based on PSU though, but on thermal performance. So it is not a case that the SMPS has short term higher rating like with a linear supply.
I checked with a local assembler (KJF), how long it was possible to run at the higher rating of 250W/4 ohm. He said they'd tested it, and after 10 minutes at 250W with no sign of limiting had stopped the test. Clearly as long as you are playing music with a dynamic range of around 7dB or more, and minimal clipping, then the rating might as well be continuous.
My gut feel is if you put a big enough heatsink on - or perhaps water cooling (
-21db music, -15 movies
That can be tricky in regions where room temperatures can approach that.
Aren't AVR's referencing THX standard?
THX standard is more for movies recorded to the standard, music doesn't particularly do that.Aren't AVR's referencing THX standard?
THX reference level explained
What is ‘THX Reference Level’? Reference level is a calibrated volume setting used for both movie production (in dubbing stages and post production houses) and reproduction (in screening rooms and theaters). The human hearing system is non-linear, especially in the bass, so having a consistent...acousticfrontiers.com
Part of the problem we have, is that movies have a reference level to which they are recorded - and which can then be applied in calibrating the system.Aren't AVR's referencing THX standard?
THX reference level explained
What is ‘THX Reference Level’? Reference level is a calibrated volume setting used for both movie production (in dubbing stages and post production houses) and reproduction (in screening rooms and theaters). The human hearing system is non-linear, especially in the bass, so having a consistent...
I don't know why you are telling me that.
I was just asking if that was what OP meant when he wrote this-->
www.audiosciencereview.com
Sorry - wasn't meant to be particularly directed to/at you....I don't know why you are telling me that.
Denon AVRs vs Integrated stereo Amplifiers for 2 channel music
Whereas typical class D designs, are much more efficient, and engineered to their rated spec... with a switching power supply, and an amp designed that way, you get exactly that - your 100W amp will give you 100W and nothing more - no headroom beyond. Often rated continuous power and peak power...
Plus - for THX reference levels to apply then the reproduction system/room need to be calibrated to that standard - Ie it necessarily results in a reference SPL level in the listening space.
Yeah basically -17 is about 75db spl at mlp.
Given we are discussing calibration and reference levels and those are measured using pink noise.... that would be continuous? (not that the question is invalid... just checking assumptions)
