So we're to go off hearsay in terms of consistency? And this being compared to hand made parts?!
AD does a nice thing where they plot some distribution data: http://www.analog.com/media/en/technical-documentation/data-sheets/ADA4898-1_4898-2.pdf
Now, admittedly that's a premium part, but those distributions are very good.
I'm unsure if/who AKM uses for their foundry, but large inconsistencies in larger patterned parts (not talking binning of microprocessors here) wouldn't make it out of most any fab.
AD does a nice thing where they plot some distribution data: http://www.analog.com/media/en/technical-documentation/data-sheets/ADA4898-1_4898-2.pdf
Now, admittedly that's a premium part, but those distributions are very good.
I'm unsure if/who AKM uses for their foundry, but large inconsistencies in larger patterned parts (not talking binning of microprocessors here) wouldn't make it out of most any fab.
Interesting, as I really can't think of any reason they would show such a behaviour. Were you told any cause for that effect?
I know all of the components that go onto a SIL-994 are matched between 0.1%. And the units themselves are as well. I doubt the LM4562's are all within 0.1% of each other.
I think he's trying to attempt to discuss an effect where old IC's were not appropriately laid out to avoid thermal mismatch across their input pair. This is no longer an issue, but is a common trope brought up against IC opamps.
I asked both Dustin Forman and Martin Mallinson of ESS this question. I asked them why they chose the AD797 for the output stage of the Resonessence Labs Mirus, instead of a discrete design. The #1 reason of course was cost. But they both said above 100hz, you will never beat an IC opamp. It's when it is subjected to frequencies below 100hz when the performance degrades. And it degrades throughout the entire bandwidth, not just below 100 hz. I can't remember the terminology they used but something to do with the low frequencies heating it up inside, with everything crammed so close together performance degrades. I asked Dustin if cost was no object what would he use in the Mirus instead. He said he designed a hybrid IC opamp/discrete circuit that takes advantage of the best from both all in 1. I'm not sure if we will see that in their next flagship DAC or not.
This could matter in an extremely heavily loaded opamp, not at line levels (unless, for example, you're aiming for the ultimate precision oscillator or low noise preamp where the feedback network is very low, but we have threads for that). It's the stuff of test equipment.
Not necessarily technically wrong, but much for making a good story and something unique to market than applicable to the circuits at hand here. An effect well below even the broadest of definition of audibility (-120 dB or less).
Not necessarily technically wrong, but much for making a good story and something unique to market than applicable to the circuits at hand here. An effect well below even the broadest of definition of audibility (-120 dB or less).
Well the buffer for the NC-500 is more than line level conditions. It's very easy to hear the superiority of the SIL-994 when compared with the LM-4562.
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For civility and to not trot out old differences, I'll abstain from taking your bait about "sonic" superiority.
I thought the buffer's load was 2kΩ? Surely that isn't low at all, especially for a 49720.
I thought the buffer's load was 2kΩ? Surely that isn't low at all, especially for a 49720.
It's 1.2k. Well the beauty of this design is choose which ever sounds best to you. If they all sound the same to you, choose the cheapest one. The LM4562 so far has the lowest score for listening satisfaction in this buffer between it, the Sparko and SIL-994.
If either the Nord or ATM amps with SIL-994 are too overpriced, you can always go for the $5000 Bel Canto REF 600m's with IC opamp based buffer.
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This is absolutely obvious - number of points (samples) in the FFT analysis. To have a tool and to know how / be able to use it - two different things. One without the other is pretty useless.
So are you saying he used it wrong? I was thinking the gaps between the points was a bit wide.
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I am saying your interpretation of those graphs (and many others) have little to do with the reality. How wrong or right he used it depends on his objectives when he made those tests, which we don't know as only raw incomplete data was presented to us.
So what do you figure he should be presenting us based on the capabilities of the aPX-525?
Complete test conditions so theoretically someone else with an aPX-525 and the respective buffer boards could reproduce. Photos of the setup. That'd be a good start.
I would speculate that the larger scale of things in a discrete circuit make quantum theory less of an issue.
I would speculate that the larger scale of things in a discrete circuit make quantum theory less of an issue.
Good point 🙂
Some subjective first impressions of the Nord Rev3 board with 994 opamp:
In my system I get the "best of both worlds" between the accuracy and detail in the treble I heard with the standard Hypex boards, and the warm, big, authoritative bass and lower midrange I got from the Sparkos and heard in the past in good Class A/B amps.
With the Rev2 and Hypex boards I heard some very light hiss from the amps with my ears pressed up to the tweeters. The Rev Cs are dead silent.
In my system I get the "best of both worlds" between the accuracy and detail in the treble I heard with the standard Hypex boards, and the warm, big, authoritative bass and lower midrange I got from the Sparkos and heard in the past in good Class A/B amps.
With the Rev2 and Hypex boards I heard some very light hiss from the amps with my ears pressed up to the tweeters. The Rev Cs are dead silent.
Landmaker thanks for the comments. It is important to know the rest of your system, to understand the complete picture.
Sebastian
Mac Mini streaming to Metrum Musette DAC, Audio Research SP17 preamp, 2xNC500s and ATC SCM19v2 speakers
The speakers are low efficiency (85db), so I would not expect to hear a lot of noise from the amps at idle, nevertheless the V3 boards are noticeably better than the V2 and Hypex OEM.
The speakers are low efficiency (85db), so I would not expect to hear a lot of noise from the amps at idle, nevertheless the V3 boards are noticeably better than the V2 and Hypex OEM.