Re: [SlimDevices: Audiophiles] External DAC on Transporter: best output option
Golden Earring wrote: > I was however under the impression that some amplifiers don't like > ultrasonic frequencies & that sticking them in can induce non-linearity > audible as IM distortion. Is this not correct? Yes, that is correct. Also applies to loudspeakers. "To try to judge the real from the false will always be hard. In this fast-growing art of 'high fidelity' the quackery will bear a solid gilt edge that will fool many people" - Paul W Klipsch, 1953 Julf's Profile: http://forums.slimdevices.com/member.php?userid=42050 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] External DAC on Transporter: best output option
Julf wrote: > Again, the "9th harmonic" is a totally arbitrary limit that results in a > *visually* nice square wave. For *sound*, what matters is *audible* > harmonics. There is no point in feeding the amp frequencies above 20 kHz > or so. Hi Julf! Well, I have to agree that there is no point. If you can believe the specs, my amp is -0.5dB at 200,000Hz, my tweeters -6dB at 40,000Hz & my 62 year old ears are hanging in there, maybe SOMETHING (i.e. -?dB) at 15,000Hz at best (although I did catch the top tone on a sweep test the other week which surprised me - it came immediately after a spoken intro so it was definitely the highest one (& a very thin "whistle") but I don't know exactly what frequency it was. Anyway, I'm sure that I've NEVER been able to hear above 20,000Hz even as a teenager before bit started falling off. I was however under the impression that some amplifiers don't like ultrasonic frequencies & that sticking them in can induce non-linearity audible as IM distortion. Is this not correct? Dave :) Golden Earring's Profile: http://forums.slimdevices.com/member.php?userid=66646 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] External DAC on Transporter: best output option
Golden Earring wrote: > Well I haven't got one so I don't know, but I suppose some electronic > gizmo capable of summing a fundamental tone with specific amplitudes of > its odd harmonics up to the 9th would get close in practical terms if my > textbook is correct. My point is that 9th harmonics can be pretty high > frequencies to chuck into some amplifiers. Or am I wrong about that? Again, the "9th harmonic" is a totally arbitrary limit that results in a *visually* nice square wave. For *sound*, what matters is *audible* harmonics. There is no point in feeding the amp frequencies above 20 kHz or so. "To try to judge the real from the false will always be hard. In this fast-growing art of 'high fidelity' the quackery will bear a solid gilt edge that will fool many people" - Paul W Klipsch, 1953 Julf's Profile: http://forums.slimdevices.com/member.php?userid=42050 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] External DAC on Transporter: best output option
drmatt wrote: > What signal generator can create a square wave? That's right, a > theoretical one with infinite bandwidth! > > Sent from my ONEPLUS A3003 using Tapatalk Hi Doc! Well I haven't got one so I don't know, but I suppose some electronic gizmo capable of summing a fundamental tone with specific amplitudes of its odd harmonics up to the 9th would get close in practical terms if my textbook is correct. My point is that 9th harmonics can be pretty high frequencies to chuck into some amplifiers. Or am I wrong about that? Dave :) Golden Earring's Profile: http://forums.slimdevices.com/member.php?userid=66646 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] External DAC on Transporter: best output option
arnyk wrote: > The cheapest , easiest way to do ABX tests is with one of the software > ABX comparators. I strongly recommend getting some experience and > listener training with one of those before trying ABX tests running on > real hardware. > > Just about any kind of physical ABX can be transported to the realm of > software ABX, but you have to have some faith in science to do so. You > have to believe that: > > (1) You have to believe that it is possible for digital recordings to be > sonically blameless. > > (2) ADCs exist which are sonically blameless. If that is true then you > can record audio signals and the recordings will representative of > reality. > > (3) DACs exist which are sonically blameless. If that is true then you > can record audio signals and the recordings will representative of > reality. > > These are all scientifically true, but I know that I am often dealing > with people that doubt established science. Morning Arny! I can understand what you are saying, but given that I'm trying to compare 2 DAC's doesn't your assumption 3 sort of assume away my comparison? I know that you don't expect me to detect anything objective in my proposed DBT (& I'm prepared to accept the objective evidence of my test, so I'm not being close-minded, probably more like bloody-minded!) but surely if everyone assumed that all currently accepted scientific hypotheses are correct they could never be falsified because nobody would ever carry out an experiment that *-might-* falsify them. The whole thrust of the scientific method is that all hypotheses remain provisional, at least to some extent. Even Conservation Of Energy, Laws of Thermodynamics, etc. As previously noted, Einstein spent about 30 years trying to find a flaw in Quantum Mechanics although he didn't succeed. He wasn't being a bad scientist by trying, he just appears to have backed the wrong horse, like Sir Fred Hoyle did with his Steady State alternative to Big Bang. Maybe in 100 years time this will all appear differently. Alain Aspect probably wouldn't have carried out his 1982 (got it right this time) "action at a distance" experiment had the dispute between Bohr & Einstein not been so passionate & protracted. I don't have much of an alternative theory to whichever hypothesis you're deriving your conclusions from, it's just that I still feel like I'm hearing something that you're adamant I can't be hearing & I want to experiment. What's wrong with that? 99.% I'm doomed to failure, 0.0001% I might get a Nobel Prize like those Bell engineers :D (of course I'm not serious). Dave :) Golden Earring's Profile: http://forums.slimdevices.com/member.php?userid=66646 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] External DAC on Transporter: best output option
What signal generator can create a square wave? That's right, a theoretical one with infinite bandwidth! Sent from my ONEPLUS A3003 using Tapatalk -- Hardware: 3x Touch, 1x Radio, 2x Receivers, 1 HP Microserver NAS with Debian+LMS 7.9.0 Music: ~1300 CDs, as 450 GB of 16/44k FLACs. No less than 3x 24/44k albums.. drmatt's Profile: http://forums.slimdevices.com/member.php?userid=59498 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] External DAC on Transporter: best output option
Julf wrote: > A slightly rounded square wave. Hi Julf! Sorry, had to clean up & medicate, then I've been working on the post above. "All Right Now". What I meant was a square wave from a signal generator which I presume IS pretty much square, but even if you truncate at the ninth harmonic it would still include some fairly high frequencies that not all amplifiers would be comfy with, surely? Dave :) (they're working now - equally strange) Golden Earring's Profile: http://forums.slimdevices.com/member.php?userid=66646 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] External DAC on Transporter: best output option
Hi all! Whilst we're working on the detailed design (& possible remote computerised control) of our ABX switch box, I thought I'd put down my ideas so far on the practical aspects of the DBT. These are the Rules Of Engagement: 1. Level matching to 0.1dB or better for each balanced input of the switch box will be set using a dual mono 1kHz sinusoidal test tone by means of trimmers *-inside-* the box which should not need to be opened during the test in case the cat gets out. Panel members will be able to verify that this has been done correctly by observing measurements taken from the output of the switch box. There is obviously no separate input for "X", but the fact that the switch box is functioning correctly (i.e. adhering to the same level settings when switched to "X") may also be checked, together with the "A" & "B" signal levels, at any time during the test on request by a panel member in the same manner. This level-matching will be checked again the same way mid-way through & at the end in any event. 2. I shall preselect a selection of well-recorded & diverse programme material from my eclectic selection of 6,500 albums (say 20 tracks) designed to cover a wide range of genres, AAD/ADD/DDD material, and lossless formats (16/44.1; 24/44.1 or 24/48; and 24/96 or 24/192). Obviously any 24/192 will be transcoded to 24/96 by LMS before onward transmission to my Transporter. Participants will also be encouraged to bring a *-small-* number of tracks of their own lossless material, which I shall be pleased to include at this preliminary stage for the listening panel as a whole to consider whilst the final shorter list is being determined (see Rule 3). 3. All of this programme material will be used for an initial acclimatisation phase of the test. Any specific tracks which are not to the musical taste of members of the listening panel can be identified & eliminated at this stage, although the requirement for a variety of genres, recording methods & formats will remain paramount. So anyone who only likes Country & Western will be in for a rough time. I would hope that we will be able to retain around 10 individual tracks for the actual test as a result of the listening panel's expressed preferences. My adjudicator's decision on the final selection will however be binding if the panel are unable to agree on the selection themselves. 4. There is no rule 4. 5. The acclimatisation period will be of fixed duration, say 90 minutes. If any panel members are unable to detect -*any*- differences between the known sources "A" & "B" after this time, they will be given a further 30 minutes of acclimatisation during which they can call the programme material from our final selection of 10 tracks, either jointly or severally (in the event that this pertains to more than 1 panel member). If they are *-still-* unable to distinguish the known sources, they will be assigned alternative roles (operator, scrutineer, or chief tea-maker - there are separate rules for that btw :cool: , or even gofer) because their further participation in the test would be pointless - they could only make blind guesses. Panel members will be encouraged to describe the subjective differences they think that can detect between "A" & "B" in best "Stereophile" tradition as colourfully as their erudition will permit (because we're all curious) & which source they prefer from a musical standpoint. These comments will be reported along with their subsequent relative success (or failure) rate over the course of the objective test to identify "X" under double-blind conditions, although I promise to do this anonymously. More to come, & I may need to edit this because I'm formalising my ideas as I type it. I don't want to bust the word count. Dave (cheerful, but emoticons have packed up - strange) Golden Earring's Profile: http://forums.slimdevices.com/member.php?userid=66646 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] SPDIF is evil
Golden Earring wrote: > > Relaxing into the music now (Emmylou Harris + Mark Knopfler today, All > The Roadrunning That's exactly what I was doing yesterday, appreciating the technology uncritically with one of my favorite albums. LMS on a dedicated server (FitPC3) Transporter (Ethernet) - main listening, Onkyo receiver, Paradigm speakers Touch (WiFi) - home theater 5.1, Sony receiver, Energy speakers Boom 1 (WiFi) - work-space Boom 2 (WiFi) - various (deck, garage, etc.) Radio (WiFi) - home office Control - Squeeze Control (Android mobile), 2 Controllers (seldom used), Squeeze Remote (on Surface Pro 4) Touch x 1 - spare UE Radio x 1 - spare Boom x 1 - spare Controller x 1 - Spare Duet Receiver (backup) RonM's Profile: http://forums.slimdevices.com/member.php?userid=17029 View this thread: http://forums.slimdevices.com/showthread.php?t=71464 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] External DAC on Transporter: best output option
Golden Earring wrote: > > > P.S. My new friend is investigating the possibility of using readily > available & cheap USB-controlled internal relays in our switching box > design which might enable us to dispense with Wombat's services & move > between trials when the panel are ready using a computer program that > could generate a random assignment of "X" & keep track of the panel's > responses to each trial. This might make it possible for the listeners > to switch A/B as often as they wanted, together with switching to X for > comparison at will, & then record their decision regarding X & press > "next" to initiate the next trial. We could printout the %age correct > for each listener for the whole test & program in the statistical > analysis also. Be good if we could pull that off, switch box would be > completely re-usable for future testing with the same listeners or > different ones... The cheapest , easiest way to do ABX tests is with one of the software ABX comparators. I strongly recommend getting some experience and listener training with one of those before trying ABX tests running on real hardware. Just about any kind of physical ABX can be transported to the realm of software ABX, but you have to have some faith in science to do so. You have to believe that: (1) You have to believe that it is possible for digital recordings to be sonically blameless. (2) ADCs exist which are sonically blameless. If that is true then you can record audio signals and the recordings will representative of reality. (3) DACs exist which are sonically blameless. If that is true then you can record audio signals and the recordings will representative of reality. These are all scientifically true, but I know that I am often dealing with people that doubt established science. arnyk's Profile: http://forums.slimdevices.com/member.php?userid=64365 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] External DAC on Transporter: best output option
Golden Earring wrote: > OK, but what are you subjecting your amplifier to if you stick an actual > square wave from a signal generator through it? A slightly rounded square wave. > BTW, I don't actually like the sound of square waves myself! Does it matter? You never find a pure square wave in nature. > What is the significance of that? I read that if the waveform didn't > actually complete a cycle it was essentially undefined. Perhaps I'm > reading the wrong book? Well, yes, a fourier transform is only defined for a cyclical waveform, so you have to have at least one full cycle. > I've been creeping around under my car putting rust converter on rusty > bits, i.e. pretty much everything, & my back's screaming... I feel your pain - it is messy too. "To try to judge the real from the false will always be hard. In this fast-growing art of 'high fidelity' the quackery will bear a solid gilt edge that will fool many people" - Paul W Klipsch, 1953 Julf's Profile: http://forums.slimdevices.com/member.php?userid=42050 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
