Re: [SlimDevices: Audiophiles] How is Audiodiffmaker meant to work?
I made a CD with the pink noise cited that came with the prog, had to pad it out 1s either side and convert to 44k1 using Audition to get it on the CD. The active part is very short. I then ran this through an Iriver portable CD player and recorded the signal using the Sound Devices 702. I've attached part of the residual. This time no minimum is detectable, though the residual is much lower. The pink noise is not steady noise - a change in tone colour is audible at several points in it and these changes correspond to the spikes, and are curiously repeatable across the channels - the CD source L and R channels are simly duplicated, but the replay and recording are two separate channels. My recording peaks at -33dBFS and the residual is say -76dBFS if you ignore the spikes, -51dBFS if you don't ignore them. System noise is slightly lower than the residual - you can just see the run-in where the noise was padded with silence before. Being charitable to audiodiffmaker the difference between the same thing repeated is -43dB relative to the original - if the spikes are included the difference is -25dB. I don't think this program is repeatable enough to show what it is supposed to show at all. I don't share the belief that all digital paths sound the same but I *do* think the same digital path will sound the same 10 seconds later. I have some scores in the cable and vibration-sensitive department I was hoping to settle with this (and I'm open to testing digital paths that sound apparently different :) However, as it stands this program isn't cutting it. If it *needs* wordclock synchronised across replay and recording systems then audiodiffmaker really ought to say so in big red letters. Though I can synch the SD to an external source and or send wordclock out of it I don't have have a CD player or squeezebox that can do that so I've reached the end of the road with it. As an independent observer I have *not* been able to replicate the results that program is claimed to show. +---+ |Filename: residual.jpg | |Download: http://forums.slimdevices.com/attachment.php?attachmentid=3128| +---+ -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=37352 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Transporter Troubles
occam;219418 Wrote: http://www.ewh.ieee.org/r6/san_francisco/pes/pes_pdf/PGE_Presentation_TransformerHum.pdf The Creek amps were/are well known for their toroid transformers humming with the presence of an dc on mains lines (easily seen with a dual trace scope with both ac and dc coupling), and the elimination of such demonstably eliminates that hum - http://www.diyaudio.com/forums/showthread.php?threadid=104626perpage=25pagenumber=1 OK, it's a fair cop, there appear to be some situations where you do get parasitic DC - I can't really argue with the PGE article, though their DC was on the 230kV HV side. Presumably 4A on that side counts for more than 4A would on someone's long way downstream 110V side since there are proportionally more turns to create a greater magnetic field. -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=30856 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] How is Audiodiffmaker meant to work?
opaqueice;219539 Wrote: And there's also the ADC clock - maybe that drifts for some reason? The ADC clock will drift relative to the playout clock, even assuming the playout is jitterless. Replay clock is presumably determined by the SB1 or the server PC. However, I have used three independent ADC clocks made by widely differing manufacturers - Sound Devices, Toshiba (for the laptop) and Sony for the HiMD. They can't *all* be bad. It is, of course, possible that the SB1 DAC clock is a ropey PLL and it drifts and audiodiffmaker is correctly showing that temporal variation, in a similar vein to Omega's claims - it would be interesting to hit his SB3 with this program, I begin to wonder if the result may not actually be what you might expect... I recorded a 30s chunk, played out at 44k1. That means 1.3 million samples. 'This' (http://www.springerlink.com/content/q257543588327v45/) indicates the short-term stability of crystals is about 1 part in 10^9 but I don't know if that holds for stock parts. If it did I'd not expect to drift more than 1/1000 of a sampling period though I've had enough radio xtals that your could hear in a FM receiver if you ping the xtal with a screwdriver so they are vibration (music perhaps :) sensitive to some extent. It is true that th SB1 is the common element here and maybe I got a Friday afternoon box. I'll repeat on some other piece of digital audio gear to eliminate that last common variable. -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=37352 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Transporter Troubles
NewBuyer;219207 Wrote: In fact, PS Audio advertised an item called a 'HumBuster' (http://www.psaudio.com/products/upchbmoreinfo.asp) that was specifically designed to remove the DC on an AC line. I find it hard to trust the reports of a company that states Because transformers work when the coil magnets switch poles from North to South and back again, 60 times a second, DC forces the input coil to always sit in one direction and this makes the transformer a little crazy so it hums. Harmonics on the mains, typically inserted by nonlinear loads such as phase controlled lamp dimmers, switch-mode power supplies and some linear PSU configurations will make transformer laminations buzz. DC on the mains will be forced through the very low DC resistance on the offending transformers and other devices on that circuit, including the substation transformer. This tends to be very low, less than an ohm for even a small transformer. Sustaining a significant amount of DC on your AC line in the face of these extremely low impedances shunting the line isn't possible without putting a massive amount of energy into it. Which will be turned into heat by your transformers, and wispy curls of smoke -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=30856 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] How is Audiodiffmaker meant to work?
I'd go further and say this program is of extremely limited practical usefulness, at least with external recordings (ie not made by itself). And I'll only give it that qualification rather than a full NFG because I haven't tried that. I recorded the output of the SqueezeBox 1 for 30s using Sound devices 702, then pressed red power off button and then play and play again to start track again. All the while recording the analogue out. Split resulting recording into first section and the second - no questions, no pack drill, these *are* the same thing. Stick this into audiodiffmaker. Result, perfectly audible if bassy track, a short-lived null at about 18s followed by perfectly audible track. Okay, perhaps Sound Devices clock is not stable enough. If that isn't, you average sound card isn't either... So I record simultaneously L of SB1 with the left of the same box but through the Arcam Black Box external DAC. One wired to the L channel of the SD702 and the other to the R channel. Now the clock must be synchronous either side, subject to the small latency spread (about 14 samples @ 44k1). Neither piece of kit is modded in any way. Resultant diff signal is about 30dB down with bass peaking at -15dB. Even I don't expect there to be so much difference between the two. I check for channels switched by repeating with the channels switched - this time diff signal sounds like classic stereo differencing and residual averages higher. OK so I probably got the channels right. For a final sanity check I take a phono y splitter and feed the same signal to both L and R of the recorder, via the selfsame cables. Now we're talking - residual down to -90, some peaking on LF to about -80. So at least satisfactory operation can be achieved if the recordings are not separated in time greatly So the Audio Critic guy is probably wrong in this case. Writing off the time-separated recordings as beyond the capability of the program, the simultaneous recording of the Squeezebox1 LH and the same feeding the Arcam BB1 LH show a difference. Audiodifference as recommended by Audio Critic to prove the converse indicates there is a significant difference at about -30dBFS. As a final sanity check I sent a 440Hz + 1kHz signal peaking at -3dBFS through both bits of kit to see if there was significant clipping or anything else obviously wrong, and both came through OK, though the spectrum of residual spurs were different. -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=37352 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] How is Audiodiffmaker meant to work?
Okay, so I try this again, using my Toshiba laptop and another copy d/l just now. I have to rack the digital gain of the SB1 down to keep it within the input range of the line-in, but I do the same as before. I record the beginning of a track, stop, record it played again. The actual track used is different from the previous tests, I can't stand hearing the other one again. Difference signal peaks at about -35dBFS, this time mainly on the bass and cymbals. Difference is again perfectly recognizeable. Once again there is a short minimum at 18 seconds in, though the recognizeable song never actually goes away. This is done in the original mode the prog is intended, using itself to perform the recording. Then just for the hell of it I repeat with a HiMD recorder set to PCM mode and digitally transferred, and inserted in the same was as with the SD recorder. Residual peaks around -30DBFS mark. So now everything apart from my Squeezebox1 has been substituted - and each of these recordings should be exactly the same - no change between the successive recordings of gear, volume, moon phase, cables, incantations and curses... Now there are a number of possible conclusions: 1) I am lying, my results are the same as yours. Only I know that categorically, but I do have lots of recordings now :) 2) This program is duff - or I have downloaded two duff copies of this program v 1.10 from Audio Critic - one today and the other a couple of days ago 3) My SB1 system is playing up in the same way as Omega claims in this thread, ie its performance is not invariant in time. I'm damned if I can hear it, but then I haven't sat down to listen to a song repeated that hard 4) I have three independent duff recorders, which are mutually conspiring to give a similarly audible signal related problem. 5) Some other combination of effects of the highest audiophile voodoo But the one thing I cannot conclude from this is that this program shows me there is no variation in electronic pathways. It is just not repeatable enough - unless it is in fact repeatable and it is showing my SB1 has condition 3 and I simply don't have Omega's finely tuned hearing and/or my old audio system is masking the difference! I'm not quite ready for that leap, and I favour 2 over 3 at the moment. -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=37352 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Design miss in SB3 digital output? or Slimserver problem ?
schatzy;218599 Wrote: If Omega thinks there is a difference between the first track played and the second played and that it makes a difference turning if off and then back on that is his opinion and no one should or has the right to tell him he is wrong. That is how his ears hear it. Maybe mine do not but that does not make omega wrong. Your atomized world of universal relativity is all fine and dandy. We each hear with our own ears, in our own rooms, though our own minds etc. Unfortunately that sort of philosophy doesn't help us all get together to fix something, because if there is a fault to fix it must be reproducible and observable by more than Omega. The reason why he is taking some flack is because - read the title - he claimed this second playing effect was a DESIGN MISS (implied = FAULT) in the slim devices product. It might be, but if it is a design fault, then it is *repeatable for different observers*. Different observers were unable to repeat it. Omega might still have a sample fault, in which case it will be repeatable - but for him. It will be independently observable, hopefully on test gear, but for his particular box only. Or, perhaps, because his buddy observed it too, for the Swedish version of slimserver, or the SB running on Swedish mains, whatever. It the very least it must be independently observable outside his subjective perception. That means other people must observe it in a controlled setting (= not warmed up by Omega as in here, this thing sounds much better the second time than the first, don'tcha agree?), or measurement should indicate a difference. The particular program advocated for measurement is junk IMO - the Audio Critic guy seems to be just as bad as the hard nut subjectivists, just in the other way IMO - but I can only say that *after* I have tried the program and found the results non-reproducible, compared to the advertised operation. The only people who have been able to reproduce this 'design miss' are Omega and his buddies AFAICS - and there is enough unusual behaviour associated with one of those buddies that there is a strong suspicion they are one and the same person. Omega may have a point - perhaps there is something screwy about how his SB works on his server. But he hasn't gone about trying to get independent confirmation of his results, simply raised the stridency of his claims. Dragging in logically unrelated red herrings like how people failed to realise jitter was an issue in the early days of CD etc doesn't actually strengthen his case. How are Slim Devices meant to fix his problem if a) it hasn't been confirmed to be a problem outside his signal path, and b) neither test equipment nor other *independent* listeners can reproduce his results? He has not in any way *proven* that this is a problem for other SB users. And he hasn't gone about getting independent confirmation that it is a problem with his (or even th Swedish) SB in a particularly organized way that could be used to chase it down. The fault he claims to have clearly is not one that affects other SB users outside his circle of friends in a significant way. -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=36503 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Design miss in SB3 digital output? or Slimserver problem ?
johann;219110 Wrote: ermine, Now you made me feel ashame to be Swedish. ;) I don't know, you have beautiful girls and some decent mobile phones by S E- you guys don't have such a hard time. I didn't like the prices in your bars though :) Seriously, though, there is a precedent for the slimserver possibly having a problem with a Swedish configuration. We already know that some aspects of slimserver have problems with accented characters eg this thread. This is why Agnetha Faltskog needed editing from the EAC rip before the cue sheet would show up to let her appear. It's not totally crazy to wonder whether some key server variable is being missed by a similar parsing routine, which could mean an error peculiar to the Swedish version of Slimserver, which could be a reason why other observers cannot reproduce the 'fault' - because there's no fault to reproduce. Omega still needs to come up with independent corroboration of his observations though. F'rinstance if he can record losslessly the SPDIF out of his SB then audiodiffmaker should work 100% to confirm or repudiate whether the recovered bitstream is the same. He could sniff the network traffic with wireshark, though I would guess hooking the data off by following the stream would be harder. Some hard evidence would be good. Getting more mates or even the whole company he works for to come round and agree with his claim is less useful... -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=36503 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] Transporter Troubles
NewBuyer;219200 Wrote: your AC supply (including possibly some DC on the AC powerline), ? I take it you mean RF on the powerlines? You don't get DC on AC powerlines. If you did, if would quickly get fixed when people notice the wisps of smoke curling up from transformers in their gear. -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=30856 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
[SlimDevices: Audiophiles] How is Audiodiffmaker meant to work?
I saw in this thread reference to audiodiffmaker and wonder if anybody has got this to work right. I have a scummy old squeezebox 1 and I've finally finished ripping my CDs to flac after two years and one HD crash ;) Backup is good to have, and I didn't... I'm not particularly enamoured of the SB1 sound though it's fine for the price, and I run it through an Arcam Black Box using optical - the same BB takes my Arcam CD player via coax. Most of my hifi is from the mid 1980s apart from the speakers and CD playing bits from the 1990s - Audio Research SP8 driving a NAP 250 into Naim SBLs. Has served me very well for the last 15 or so years though somewhat decrepit by modern standards. Anyway, I am in the market for something better than SB1 now I have finished the CDs and I read the arrogant S.O.B. on the Audio Critic referenced by Sean in that thread. The Audio critic reprises the 'all electronics sounds the same' doctrine. I have to give him the benefit of the doubt, if his audiodiffmaker works as he says it does, I should find a difference between the SB1 and the Arcam black box, or there is no audible difference. I tried this, recording the output of the SB1 into my preamp using phono Y connectors to patch the signal at preamp-in into a Sound Devices 702 set to record at 48k 24 bit, then repeating this using the Arcam Black Box fed via SB1 optical SPDIF (which comes out a lot louder than the SB1). The SD702 should be a lot better than a sound card, though it does mean you have to take the signal into audiodiffmaker as a pair of files, which is possible but not the usual way it seems ot be used. Anyway, I expected the difference, if any, to sound hard to hear in a hissy background. It isn't - the difference signal is massive, and sounds like a rather dull copy of the original with the very low frequencies boosted a lot, but I can easily follow the voice. I even tried swapping channels in case I had screwed up there (result, phasey echoey dull copy of the original) and feeding a copy of the original in for both signals (result - silence, phew!) Anybody tried this? I didn't match levels to more than 10dB on the recording because this is what I thought audiodiffmaker should do, I simply made sure they didn't go over the top. According to this, either the Audo Critic's thesis is wrong Every low-distortion electronic signal path sounds like every other. The equipment reviewers who hear differences in soundstaging, front-to-back depth, image height, separation of instruments, etc., etc., between this and that preamplifier, CD player, or power amplifier are totally delusional. and it is wrong quite demonstrably, using the software he recommends to prove the contrary, or I screwed up royally in using audiodiffmaker, or audiodiffmaker doesn't propery compare the two files. I have listened to the source files, they sound like the first 30s of the same track to me. Anybody got experience of this program and testing a squeezebox? I know SB1 was probably not slim devices' finest product, but its output shouldn't be so measurably diferent from its spdif into the Arcam black box! FWIW I had the devil's own job locating Audiodiffmaker on the web - it is 'at the bottom of this page' (http://theaudiocritic.com/blog/index.php?op=ViewArticlearticleId=35blogId=1) -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=37352 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] How is Audiodiffmaker meant to work?
opaqueice;219008 Wrote: The most obvious candidate is bad level matching - maybe audiodiffmaker doesn't do a great job with that. You can test that by changing the level of one of the files with another program (Audacity, say) and then run diffmaker on that modified file plus the other, and see if the difference file is the same as before (it should be if diffmaker works properly). Hmm. I take one of the recordings I made earlier, of the black box section I think, but it shouldn't matter. I then run this into Audition, lower the level by 10dB and compare it with the original. Audition is set to dither at 16bits. Diff needs amplifying by 60dB to reach 0dBFS and is a hissy copy of the original, with the bass jacked up massively. It is, however, perfectly easy to follow the song and hear the words, though there is also plently of signal-dependent noise. This is not what I expect to be the results of nulling out a digital 10dB attenuation, and starts to indicate to me that this program is not as useful as it is cracked up to be. There is, of course, the possibility that Adobe were incompetent in their implemenation of digital loss so jury's out. I then record the output of my SB1 again. Okay so I didn't match levels, I should have recorded two in succession I guess. I compare this with yesterdays. I expect this to give me a null. My section is 30s, a sort of null occurs at 17s and then the diff signal becomes bassy copy of the music. Almost as if the sampling rate changed slightly and one copy is phasing in and out. Okay so maybe Sound Devices should do better, but it's just not reasonable to expect a recorder to drift less than half a clock cycle over 30 seconds - that's less than one part in a million. Audio Critic's pal's software has to have a way to correct for that else the program isn't really useful in the real world. The impression I had gotten from the Audio Critic's cocky promotion of the prog was that this program would correct for linear distortions in time and in amplitude. I guess I can't complain too much, can't beat the $ price, but it has wasted some of my time... opaqueice;219008 Wrote: If it's none of those it's probably really there. Incidentally that's not necessarily so surprising, even from the audio critic's point of view (which I more or less share).). Yeah, no problem. We're all entitled to our religious viewpoints, I'm not even saying mine is right, it worked okay for me. Listening rather than reading specs bought me a stereo I've enjoyed for the last 15-20 years and the key bits even survived the change from records to CDs. What seems to be killing my enjoyment now is the rotten mastering of current pop/rock CDs :( I'd merely picked up on this program because it did seem to be really promising as a way of chasing down true nulls and/or proving the existence of subtle differences. But it seems to find too many differences to be useful to me. I'm not ready for sonic differences in mains leads etc and I was hoping to apply this to some of the more outlandish claims, or find there is something there even though that sort of thing isn't audible to me. Or maybe I am not licensed to drive diffmaker, maybe I need to believe in the invariance of electronic pathways before it'll play... At least I got a null with two copies of the same thing so I can't be doing too much wrong! Thanks for the pointers. I'll give it one more try recording the same thing twice immediately one after the other. I want to get at least one bona fide null out of this program before I toss it! -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=37352 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] New User - Please help with 96K playback
amcluesent;216839 Wrote: 96/24 is confusing! As the GBP:USD rate is so good, I d/l Symphonie Fantastique as a FLAC from HighDefTapeTransfers.com (Meta tags were non-existant BTW). Thank you for the tip to this place! I've never seen the point of paying to d/l crappy compressed music before. Now at least I can see a reason to pa yto d/l, I'll give this place a go. Must be a moral in there for the record companies in there somewhere! -- ermine ermine's Profile: http://forums.slimdevices.com/member.php?userid=12613 View this thread: http://forums.slimdevices.com/showthread.php?t=36986 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
