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Post by macca on Jul 4, 2019 13:29:25 GMT
Yes, I notice that ASR tests amplifiers with dummy loads. I think the reason is that it is pretty complex to do anything else. It's still valid for comparisons though as all amps will be tested the same way. As someone noted above, they are not interested in what they sound like.  |
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Post by dsjr on Jul 4, 2019 14:24:50 GMT
There's a thread there discussing making a simulated speaker load as Stereophile do, so we'll see what happens. In the meantime, a review of the current Naim 250DR power amp. Testing obviously not the same measurement gear, but they do seem around '20db better' than a CB250 as tested in a mid 80's HFC book. Note how the response into a typical speaker load changes - not so much with this (around 1db), but many valve amps are significantly worse and this *is* clearly enough to be audible, un-sighted or not... i.nextmedia.com.au/Assets/naim_nap_250dr_power_amplifier_review_test.pdf |
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Post by macca on Jul 4, 2019 15:11:50 GMT
Good set of results but then it does cost about three grand.
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Post by macca on Sept 24, 2019 12:13:49 GMT
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Post by dsjr on Sept 24, 2019 12:48:49 GMT
It uses a technology that is popular in audiophile circles I gather, a solution looking for a problem, the negatives on doing the filtering? conventionally seemingly academic rather than an audible issue. I could very well be wrong though. The whole point about over-sampling was supposed to help to sort this aspect, or so I naively thought.
One thing that hasn't been 'listened to' which I'd love to find if it's audible, is the 'ESS Distortion hump,' where this chipset has in the past had a tendency to increase distortion a good bit at typical music mastering levels in the past (-30 - -50db levels) due to possible slightly inappropriate implementation. ESS chips in the past were criticised for having a brighter, more 'detailed' sound and I just wonder if this may be a cause? More manufacturers using these chips have now found a way to deal with it and it's now a non-issue in latest dacs.
Lots of very clever maths going on in digital audio technology. The pro's seem to have it pretty much sorted, so what's gone wrong with some of this domestic Sh#t?
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Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,400
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Post by Bigman80 on Sept 24, 2019 12:50:45 GMT
Of course it’s come on leaps and bounds. From fifty quid to 6 grand is quite some leap! |
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Post by dsjr on Sept 24, 2019 13:04:08 GMT
Amazing how some of the earliest CD players don't sound half as 'bad' with modern systems as they did at the time with vinyl-based horror-stereo's of the period. The main thing I noticed with the earliest domestic stuff heard today is a lack of reverb-tails and spacial 'depth' in general, but the harshness we complained about isn't really in the players or discs I now find. On the pro side, an original Sony 1630 wired in a tape loop, sounded absolutely identical to the straight-through signal and even the extra interconnects didn't seem to matter...
That PS dac has output transformers, and maybe not good enough ones as bass distortion is the main killer here. makes me think of my Micro Seiki, which is used from it's transformer coupled balanced outs. I love the bass but now have doubts as to whether it's transformer saturation over-egging the pudding slightly. See chaps, I can't trust my ears to tell me what's implied or real where distortion or not is concerned... My machine's not as bassy as the replacement DC-M100 was...
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Post by macca on Sept 24, 2019 13:06:28 GMT
It uses a technology that is popular in audiophile circles I gather, a solution looking for a problem, Exactly that. Or more accurately a product that addresses what people with no bloody clue think matters.
And it's re-assumingly expensive. because the same people will tell you that you can't use a $100 DAC with your $20,000 system. presumably because the price tag has some weird effect on sound quality - you can't measure it though!
Years ago I went into a local shop to buy a clock radio and they wanted £70! - that's about £150 in today's money. Now I was no expert on the clock radio market but I had a sneaking suspicion that there was no need to pay that much for a perfectly functioning clock radio. So I went elsewhere and got one for £20. A clock radio is not complex and there's a limit to how good a clock radio can be. So why pay more?
The same now seems to be true of DACs. There's some weird sort of bubble that has been created with the people inside it thinking that the DAC is make-or-break to the sound quality of their system, and that the more that they pay the better it will get. There are still too many people on the forums reading the magazines and listening to on-line 'digital gurus' unfortunately, and they are handing out very bad advice to others, who then get drawn into it all too.
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Post by macca on Sept 24, 2019 13:23:16 GMT
Amazing how some of the earliest CD players don't sound half as 'bad' with modern systems as they did at the time with vinyl-based horror-stereo's of the period. The main thing I noticed with the earliest domestic stuff heard today is a lack of reverb-tails and spacial 'depth' in general, but the harshness we complained about isn't really in the players or discs I now find. Completely agree but it's amazing how many people still resolutely stick to that theory. There's sort of a descending 'Tree of Denial':
1) All digital is harsh because that is inherent in digital
2) Streaming is okay because it is bit perfect but CD is still no good
3) Okay more recent CD players are not so bad but early ones were terrible because digital wasn't really understood back then.
4) CD players are fine it was just those early CD releases because the engineers who did the transfers didn't understand the technology. (yes okay, they didn't understand how to cue up a master tape on an RTR and press play whilst making sure the levels don't saturate? Because that's all it amounts to. Never mind).
5) All CD players are okay and so are the recordings but much better to use a separate DAC as DACs have come on leaps and bounds - Yeah, Just like this five grand PS Audio thing that has so much distortion it has less dynamic range than a cassette player.
6) Oh actually there's nothing wrong with CD players or CDs it was the rest of my system that was Sh#t all along! Silly me!
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Post by dsjr on Sept 24, 2019 14:28:36 GMT
Two CD's I remember sounding horrible in the mid 80's or so. Vivaldi's Four Seasons/Academy of Ancient Music/Pinnock and Invisible Touch by Genesis. I didn't like much of the music on the Genesis one so never followed it up, but the Vivaldi disc - same physical disc - sounded so much better a few years later when our stereo's had calmed down, the early instruments' admittedly squeakier natural tones being reproduced more properly.
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Post by macca on Sept 24, 2019 15:31:50 GMT
'Invisible Touch' sounded Sh#t because it was Sh#t, possibly the worst album of the decade which when you consider that decade included 'The Joshua Tree' the bar was set very high.
I had a mate who had the cassette and another who had it on vinyl and both were dire. Sh#t cover, Sh#t songs, Sh#t singing, Sh#t production.
As for the Vivaldi F#ck knows. I've got The Four Seasons on vinyl, a box set. Never played it.
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Post by karma67 on Sept 24, 2019 15:53:13 GMT
'Invisible Touch' sounded Sh#t because it was Sh#t, possibly the worst album of the decade which when you consider that decade included 'The Joshua Tree' the bar was set very high. I had a mate who had the cassette and another who had it on vinyl and both were dire. Sh#t cover, Sh#t songs, Sh#t singing, Sh#t production. As for the Vivaldi F#ck knows. I've got The Four Seasons on vinyl, a box set. Never played it. a brilliant album,one of my favs,the joshua tree |
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Post by dsjr on Sept 24, 2019 16:15:25 GMT
I very much preferred The Unforgettable Fire myself - better songs, ambient production (too much for some) and before success went totally to their heads  |
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Post by sq225917 on Sept 24, 2019 17:09:04 GMT
The imd hump comes from running the L and R avcc rails on the dac chip from a single supply. Give it two rails, or add appropriate decoupling and it goes.
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Deleted
Deleted Member
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Post by Deleted on Sept 24, 2019 17:31:18 GMT
'Invisible Touch' sounded Sh#t because it was Sh#t, possibly the worst album of the decade which when you consider that decade included 'The Joshua Tree' the bar was set very high. I had a mate who had the cassette and another who had it on vinyl and both were dire. Sh#t cover, Sh#t songs, Sh#t singing, Sh#t production. As for the Vivaldi F#ck knows. I've got The Four Seasons on vinyl, a box set. Never played it. I like invisible touch. Have it on vinyl and apart from the last track on each side it sounds good |
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Post by antonio on Sept 24, 2019 17:42:36 GMT
The imd hump comes from running the L and R avcc rails on the dac chip from a single supply. Give it two rails, or add appropriate decoupling and it goes. For me this makes no sense at all. If you are trying to be helpful do try and word it in a manner everyone can understand. |
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Post by macca on Sept 24, 2019 17:59:28 GMT
With a better power supply it goes away.
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