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Metatron

Wammer
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About Metatron

  • Rank
    Aurally Satisfied

Personal Info

  • Location
    Bracknell

Wigwam Info

  • Turn Table
    Old Rega P2
  • Tone Arm & Cartridge
    RB300 with AT33PTG
  • SUT / Phono Stage
    something crap
  • Digital Source 1
    Bespoke Roon Server
  • Digital Source 2
    RPi3/dCS Net Bridge
  • DAC
    Chord Hugo
  • Pre-Amp
    Modwright LS36.5
  • Power Amp/s
    Pass Labs X250
  • My Speakers
    WB ACTs + Torus
  • Headphones
    none
  • Trade Status
    I am not in the Hi-Fi trade

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  1. Metatron

    RME ADI-2 DAC vs Chord Qutest

    Forget filters - if you can hear a difference (whether real or imagined) that's all that matters, unless you want to listen to something you know measures well, which is just another level of audio nervosa. Filters will become irrelevant once the Squdel Function replaces Sinc filters, as there will be no ringing of any kind.
  2. Metatron

    RME ADI-2 DAC vs Chord Qutest

    Nope - and as I said, FWIW, I don't believe ringing is audible - certainly not at 96kHz+ assuming recording and mastering took place at that resolution with appropriate filters. However, CraveDSP, Weiss and Cirrus Logic all have statements that suggest it is. The last Cirrus Logic bit I posted is where I'd like to see the evidence they speak of when they say And the same with Weiss' Such comments like that suggest there is evidence about. I've not seen it. You're a Weiss dealer - ask them for the evidence to back those comments up! What I have seen put out by individuals like Archimago or troll is contradictory to what I've just posted by leading industry players and the former's writings are just well-argued opinion, not verifiable fact. And because it's well-argued opinion and not definitive fact, we shouldn't be throwing URLs about as if it is absolute objective fact. The more I find conflicting articles, the more I believe I have to subscribe to AES and get full access to all the papers to separate the hyperbole and subjective personal opinions purporting to be fact from the actual facts.
  3. Metatron

    RME ADI-2 DAC vs Chord Qutest

    Clearly you didn't read my post.
  4. Metatron

    RME ADI-2 DAC vs Chord Qutest

    You've not carefully read what I said if you think I am saying it is audible, because I have not said that. What I have done is question the evidence and show where in Archimago's case, he's shifted his 'objective' findings over time in regards to filters in general, as well as how some comments on ringing, such as the Troll link, do not employ subjective listening tests. As such they are argued positions, rather than validated through listening tests. And because of that, we (you) shouldn't linked to them as definitive. FWIW, I do not believe ringing is audible - but it's a belief. Watts' position on what resolution is audible would suggest (but not prove) that distortion from ringing as seen in Archimago's graphs is audible, even if difficult to discern from a better reproduced waveform without those distortions. I said there wasn't enough evidence that I've seen to support that view either. Again, I'm emphasizing you can find various non-AES blurbs that seem scientific without peer-reviewed independent confirmation of results, and without subjective listening tests to confirm. Here's a professional DSP company example: https://cravedsp.com/blog/linear-phase-eq-explained Or especially for you as a Weiss dealer saying it's not audible, here's something from the Weiss DAC 202 manual suggesting they think it is (http://www.weiss.ch/files/downloads/dac202/DAC202-manual.pdf): Again, a low pass filter, which is called a „reconstruction filter“, is here to suppress those frequencies. The same applies to the reconstruction filter as to the anti-aliasing filter: pass-band up to 20 kHz, transition-band between 20 kHz and 22.05 kHz, stop-band above 22.05 kHz. You may think that such a filter is rather „steep“, e.g. frequencies up to 20 kHz go through unaffected and frequencies above 22.05 kHz are suppressed to maybe 1 100 000 th of their initial value. You are right, such a filter is very steep and as such has some nasty side effects. For instance it does strange things to the phase near the cutoff frequency (20 kHz) or it shows ringing due to the high steepness. In the early days of digital audio these side effects have been recognized as being one of the main culprits for digital audio to sound bad. ... The problem with the upsamplers is that they are filters again, digital ones, but still filters. So in essence the problem of the analog reconstruction filter has been transferred to the digital domain into the upsampler filters. The big advantage when doing it in the digital domain is that it can be done with a linear phase response, which means that there are no strange phase shifts near 20 kHz and the ringing can also be controlled to some extent. Or we could examine a Cirrus Logic paper (https://d3uzseaevmutz1.cloudfront.net/pubs/whitePaper/DS668WP1.pdf)... The impulse response of a typical FIR filter for a 48 kHz sample rate is shown in Figure 1. Notice the ringing or “pre-echo” prior to the arrival of the impulse. This pre-echo creates what has been described as a time smear or energy dispersion of the original signal. Figure 2. shows the impulse response of the same filter at a 96 kHz sample rate. It is apparent that the pre-echo has shorter time duration and less time dispersion than at 48 kHz. It is this difference that many believe to be a primary source of the audible superiority of the higher sample rates. As a result of this, many industry experts have suggested that the additional bandwidth offered by the higher sample rates be used as a transition band to allow the use of less aggressive digital filtering, which minimizes pre-echoes and time dispersion even further. Julian Dunn [4] and Mike Story [7] have both written very nice discussions of this subject. Unfortunately as convincing as these arguments are, there is not an industry consensus as to how the additional bandwidth of the higher sample rates should be used. Many influential manufacturers and endusers continue to believe that the extended frequency response is the key to audible improvements. It is also interesting to recognize that, despite all of the attention focused on the higher sample rates and latest delivery formats, 44.1 and 48 kHz sample rates continue to dominate the industry. Assuming the shortened pre-echoes and improved time dispersion of FIR filters are responsible for the audible improvement in the higher sample rates, how can we apply this knowledge to improve the audio quality at 44.1 and 48 kHz sample rates? ...[And on pg 5]... In addition to the audibility of signal latency in live sound applications, there is a growing body of research that indicates that the audibility of pre-echoes is a primary source of the sonic differences between the lower sample rates, 44.1 and 48 kHz, and the higher sample rates of 96 and 192 kHz. Do you need me to go on, or do you get the point?
  5. Metatron

    RME ADI-2 DAC vs Chord Qutest

    Nothing wrong with the article, although he hasn't assessed actual audibility by any listening tests, but it's this line that is crucial: "ringing effects from oversampling filters can be eliminated by leaving a small margin above the highest frequency in a recording. Depending on the sample rate used, the filters needed to create this headroom" Simply because most music is now highly compressed with low dynamic range, and because they typically aren't leaving this headroom. Also, most recordings are still 44.1kHz and not aligned with the earlier comment of "If recording at 96 kHz or higher, this is hardly of any concern" Context is everything.
  6. Metatron

    RME ADI-2 DAC vs Chord Qutest

    Nick, Keith linked to an Archimago post on the old (now locked) Qutest vs RME DAC thread. The link is http://archimago.blogspot.com/2018/01/audiophile-myth-260-detestable-digital.html which he posted to claim "ringing" is not audible for Tuga. However, in 2016 Archimago posted a similar blog (http://archimago.blogspot.com/2016/07/musings-digital-interpolation-filters.html). And, in that blog he cites an AES paper (The Audibility of Typical Digital Audio Filters in a High-Fidelity Playback System). And in the AES paper's summary that is publicly accessible, it says: "Discrimination between filtered and unfiltered signals was compared directly in the same subjects using a double-blind psychophysical test. Filter responses tested were representative of anti-alias filters used in A/D (analog-to-digital) converters or mastering processes. Further tests probed the audibility of 16-bit quantization with or without a rectangular dither. Results suggest that listeners are sensitive to the small signal alterations introduced by these filters and quantization. " The key contextual piece this DOES NOT tell us, is if this is: Only filtered vs unfiltered comparison (NOS vs OS) Unfiltered vs different types of filter comparisons (which I believe is the case due to the bit I underlined above) Differentiating pre/pre-post/post ringing from simply different filter roll-offs The only thing that is clear is that the paper concludes subjective listening tests prove different filters make audible differences. Yet I want to point something out about Archimago findings.... In Archimago's 2016 article (http://archimago.blogspot.com/2016/07/musings-digital-interpolation-filters.html), Archimago concluded that we should use minimum phase filters and slow roll-off over linear phase and fast roll-off. In the 2018 article, his findings have reversed. So these articles show a contradiction in reasoning. And with that, the point I've oft been making is that there are contradictory papers in the audio field and you can pretty much 'prove' whatever you want (and in reality have proven nothing, or at least little). When a company wants to sell something new they've created, it's often led with an AES paper showing something is audible and therefore a 'problem' to audiophiles, so needs their new tech. While Archimago's articles are good, for the most part they are just rationalized arguments around things he can measure. And, he has often reached different conclusions as his differing comments on ideal filter choice between 2016 and 2018 show. And with that - it's best to use AES papers where results have been reproduced to support any arguments one might wish to make on the Wam (looking at Keith), and for which there are subjective listening tests used for evidence, rather than just somebody using well-thought out arguments to hammer home an opinion. The AES paper Archimago linked to in 2016 is partly by Bob Stuart of Meridian/MQA fame/infamy. For some, that would trump Archimago's findings, for others, it will instill a sense of pushing one's own business interests. Either way, Bob Stuart has renowned expertise in psychoacoustics and furthered audio science with independently reviewed and reproduced results of some of his AES papers. Archimago does not have this AFAIK. What is also interesting is that on the 2018 Archimago posting, he no longer links to any AES papers. One has to wonder why. And even without it, Archimago still implies different filters are audible in the 2018 article with "some people might prefer minimum phase slow roll-off filters because they sound different (as per Ayre's "Listen" filter), but technically if you care about time domain performance and frequency domain accuracy of 44.1kHz playback, you would go with a high precision, reasonably sharp, anti-imaging linear phase reconstruction filter (as per Rob Watts' video linked 2 weeks back)." [I would agree with this at least]. Lastly, is "ringing" audible... well, if we use Archimago's 2018 article, he shows the following changes to signal waveform are possible with modern low dynamic range, over compressed recordings (e.g. most of the music released today): But he also notes how short the music clip is, in that it represents 4-5ms and it is THIS ASPECT that he uses to conclude that the audibility of the distortion of the signal by ringing is a myth. The thing is, Rob Watts would contend we can detect changes to 4uS in transients. (See his RMAF 2017 presenation here: https://www.head-fi.org/threads/watts-up.800264/page-23#post-13772429). Watt's argues that pre-ringing is essential, which would at least correlate to the notion that minimum phase filters are 'bad' since they are all post-ringing. I'm not sold by Rob Watts' arguments yet either. I haven't seen an AES paper to confirm some of the claims. So I cannot make a conclusion as to who we should believe. What I can say is that Archimago has contradicted himself between two articles on filters. His views have shifted with time. I think his more recent personal conclusions are better, but that doesn't take away from the idea that he may post an article today saying one thing, and another in 2 years time saying something else again.
  7. Metatron

    DAC Off Part 2: Qutest vs RME ADI-2 DAC

    I don't know what more you want. It's been established most on here preferred the poorer measuring RME to the Chord Qutest. That more than a few are euphonophiles. And that Keith wishes to keep pointing it out in the hope you try his stuff. If you want specs or features, RTFM.
  8. Metatron

    DAC Off Part 2: Qutest vs RME ADI-2 DAC

    To be fair, Keith let Archimago and Troll do the speaking this time around, except for the Chord comment. Archimago's third point is very good. Many an audiophile is a euphonophile. And if we are euphonophiles, then Keith doesn't have that much kit we'd want. I know I like the 2nd harmonics in my Pass amp which is otherwise impeccably clean. Keith, what was that about curing RFI with ferrets? How do you get them to stay on the cable? Is it a shish kebab arrangement?
  9. Metatron

    DAC Off Part 2: Qutest vs RME ADI-2 DAC

    I'm not Keith, but none of these are perfectly recreating the original analog signal. Since that is the goal, they all are a distortion compared to the analog signal itself. If one says we start with the digital recording, then we have no analog reference. How convenient. A bit like Camverton's comment on misusing stats and measurement; arguments to reframe context can also do the same. But then all digital is imperfect, just to what degree. A 4k image made of square pixels still looks mighty fine. On NOS, you get perfect phase, while OS you don't. The approaches trade what to distort. Engineers got hell bent on perfecting FR and eliminating harmonic distortion by sacrificing perfect phase response with OS. Yet, as you noted, none of these filters actually achieve that without some unwanted effect. That unwanted effect can only correctly be described as distortion.
  10. Metatron

    DAC Off Part 2: Qutest vs RME ADI-2 DAC

    The dog is a female Basset pup, 5 months old just 2 days ago. This was a face shot while she was resting on a bean bag. Here's a crop of the original. EDIT: She slept through Bach - the famous organ works as performed by Peter Hurford. She's also got used to being able to sleep through The Glitch Mob.
  11. Metatron

    DAC Off Part 2: Qutest vs RME ADI-2 DAC

    @Camverton I couldn't agree further with any of the points you made. All on point. Repped. I too auditioned the D&D8C and found much the same. My existing speakers in-room response was actually better (smoother) above 1kHz, but both had high amounts of roll-off from an unknown cause since my room isn't currently damped - only the sofa can damp. I couldn't really add that much boost via DSP, so opted against it. I come from the school that one should limit the amount of boost to about 6dB or less and otherwise only cut the peaks.
  12. Metatron

    DAC Off Part 2: Qutest vs RME ADI-2 DAC

    I have a feeling that if I heard the RME, I might prefer it to Chord products. But it measures worse than the Qutest. By measurement definition it's less transparent. Part of me is a pedant (like Keith and his 'hifi' definition) and I quite like the SQ of the Qutest which I've already heard, so if I preferred the RME I'm starting to think I'm adding salt and pepper and moving away from transparency. F*** it's gotta be the Chord and not demoing the RME
  13. Metatron

    DAC Off Part 2: Qutest vs RME ADI-2 DAC

    Indeed. And some people like that. You could be a master chef and say it doesn't need salt or pepper, but people will discern differently and act differently. So why keep pushing people to accept the idea that perfection is 'transparency' to the recording (no salt/pepper)? It's their money, their choice and you have no right to force an alternate view or choice upon them. As I said earlier, I believe you mean well and are a helpful chap, but the endless push that people should only accept transparent products (because that's what you aim to sell) is frustrating and tiresome when it seems partly served with comments that intimate they are uneducated. To quote you yesterday... They already understand and know, but they like salt and pepper. Leave them to their freedom of choice.
  14. Metatron

    DAC Off Part 2: Qutest vs RME ADI-2 DAC

    Very much like saying salt and pepper are useless to flavour food, it should always be as it is served. FWIW, you raised the notion of faithfulness with your continuation to push faithfulness to the record as the only definition of 'hi-fi'. People listen to music to enjoy it, much like adding salt and pepper to a meal to make it preferable to how it was served. You seem to reject this out of hand and get despondent that people exercise freedom of choice. Or you disparage such choice as 'effects' - which to be honest, it is - but it's their choice. You need to stop pushing people to require transparency to a recording, especially if it's crap when reproduced transparently. There aren't always alternate versions of recordings - so that's a moot point.
  15. Metatron

    DAC Off Part 2: Qutest vs RME ADI-2 DAC

    Different but related subjects. (Live performance -> Capture -> Mixing/mastering -> Recorded Master -> Record Copies -> Playback Chain). If the notion of fidelity or faithfulness is screwed up before the playback chain, then a transparent playback chain will let you know it! Hence why people buy kit that is not transparent. Garbage In, Garbage Out.