Comments for Vinyl vs. CD - A Running Commentary - Parts 1 - 5 at http://www.hometheaterhifi.com , comment 1 to 84 out of 20 comments http://www.hometheaterhifi.com Fri, 10 Feb 2012 01:10:03 +0100 FeedCreator 1.7.3 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-4610 CD vs LPs... The battle still goes on. - For me once upon a time in the late 90s till about 2008, LPs were a cheap medium (Even cheaper than tapes & CDs). - I discovered the Clash, realised that Foreigner was a hard rock band, The Band was not a generic term ;-) and the thrill to get your hands on a mint unopened Joni Mitchell or stumble on a Bruce Springsteen box set of live performances for a few bucks only because the pawn store had no idea what their true value was.. - Hacking my Technics SL-D3 to get the best of what it could deliver And I think that's the charm of vinyl. Theres always scope to push the bar a little further. Atleast for an audiophile ;-). Digital on the other hand - like it, hate it - For sure you can't live without it. The sheer pervasiveness cannot be ignored. In my opinion the next commercial format to supplant CDs could possibly put the Digital vs Analog rhetorics will be effectively put to rest. - Aaron Wed, 08 Jun 2011 19:19:10 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-3363 John: With the resurgence of LP's, it's great that you are taking the time to take on the analog-vs-digital source quality argument in-depth – and to educate the current generation of hi-fi enthusiasts to the finer points of turntable setup. Since I was actively involved in hi-fi audio for quite some time when turntables evolved into THE source for high-end audio in the early '70's (and eventually took over as a store manager for a McIntosh dealer in the Midwest), I was intimately familiar with the settings and finesse involved in the proper set-up of a turntable/tonearm/cartridge system. I may be a little rusty on some of the terms, but I would like to offer the following feedback/clarification – please feel free to respond (or not). First, skating force really has nothing to do with “centripetal force” – it is a consequence of the geometry between the tonearm pivot and the stylus/LP contact point, and is caused by friction between the stylus and the LP. That friction force, essentially tangent to the groove being tracked at any given moment, is not directed toward the fixed pivot point of the tonearm, but to the outside. As a result, a slight 'torque' is applied to the tonearm assembly which induces the tonearm to drift toward the turntable spindle. Tonearms (back then) induced an opposing 'anti-skating compensation' torque, using either a small counterweight like the McIntosh turntable in your article (a more desirable means due to its predictable and constant force) or a small spring mechanism (less desirable due to being less predictable and not truly constant). I also seem to recall that someone even devised an anti-skating compensation system utilizing magnets but cannot recall who it was or if it was in a trial or final product. In any case, both the skating force (and the anti-skating force used to counteract it) were directly dependant on the tracking force applied to the cartridge (spring systems were typically adjusted via a small knob with markings matching cartridge tracking force settings; counterweight systems were typically adjusted by altering the distance from the tonearm pivot to the counterweight attachment point, with attachment points provided to match various tracking force settings). Ergo, skating force clearly correlates directly with tracking force. Secondly, with tracking forces slowly falling back then as cartridge technology evolved, anti-skating compensation was becoming less pronounced as a factor affecting turntable accuracy/performance (my last two cartridges, moving-coil units, were: an Ortofon with a 1.0-1.25 gram tracking force, and a Bang & Olufsen with a 1.5-gram tracking force – both around half of that noted for the McIntosh turntable). Those interested in as much precision as possible regarding turntable setup at the time (as I was), could verify anti-skating compensation empirically and, if the turntable was so capable, fine-tune it – one would merely place a smooth (ungrooved) 'LP' on the turntable (available for this purpose at that time), start the turntable, place the stylus on the surface of the disc, watch for the tonearm to drift toward/away from the turntable spindle, and adjust as needed to minimize the drift in either direction. Next, I didn't notice cartridge 'overhang' mentioned in your article. This specification (as I recall) was given by the turntable and/or tonearm manufacturer. It was intended to help achieve better symmetry between the stylus 'arc' (that described by the stylus as the tonearm swings across the LP) and the point of tangential alignment (“azimuth”) of the cartridge (which should be aligned at a point midway between the innermost and outermost grooves on the LP). This keeps the unavoidable azimuth error to a minimum across the LP by “zeroing” it in mid-arc. Lastly, I want to note that, when viewed in cross-section, stereo LP grooves have a 90-degree V-shaped profile, with each of the groove’s two edges containing information for one of the two stereo channels. Each edge, when modulated, undulates perpendicular to its surface and parallel to the other edge – which, by virtue of groove geometry, provides the primary separation between each channel’s discreet information. Because of the 90-degree V-shaped grooves, the primary motion of the stylus is not up-and-down, but movement in a diagonal direction (at 45-degrees to the LP surface) – an up-and-down motion is realized only when information is delivered to the stylus from both channels simultaneously, thereby causing the two primary (diagonal) motions to combine into a vertical motion. I hope this all makes sense, and sorry to ramble on. - G. Steenbergen Sat, 26 Jun 2010 11:05:17 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-2643 I'm just over 30 now, but have been listening to vinyl since my early 20's, though on a fairly entry level setup as vinyl goes. Sure, there are occasional pops and other sounds that shouldn't be there, but when I compare it directly to the same CD, I find the vinyl to sound more natural, warmer, and more like real life. Is vinyl convenient? Of course not. Records can warp and break, they need to be cleaned, they take up a lot of room, and I can't easily rip a copy to listen to at my computer or on my iPhone. However, I don't think any of us would keep buying it unless we thought it had a more lifelike sound that a CD can offer. No one is going to compare a $3,000 turntable to a $10 CD player, though not because the $10 CD player is inherently better as you seem to suggest. Both formats have weaknesses and strengths, and they are different and some of the weaknesses of one format are too much for someone to deal with. Your photograph argument would be much better if you compared film to digital photography. Both take a picture, but both have pros and cons about them. Film is a pain to work with, harder to develop, and more expensive, but to me it has that wonderful grain quality that looks so much better to me than digital photos. Of course, I use a DSLR instead of a film camera since, despite the fact that I might like the image from film more, it's too much of a pain for me to deal with in my life, but just because I choose to go with digital for some reasons, doesn't make it superior to film automatically, or make someone that chooses film wrong. Having a debate about this isn't pointless, it's enlightening for people on both ends of the spectrum. I find all music formats have a place in my life (I own hundreds of CD's, and I acquire mp3's if there is no other way to obtain the music I'm after), and while I wish there was a format that was always better than another one, there isn't as far as I can tell. But saying that vinyl is automatically worse because of the random pop or click is flawed. At CEDIA this year I heard one of the best demonstrations I have heard, using Martin Logan's CLX panels, with Descent subwoofers, and Diana Krall - Live in Paris from a McIntosh turntable. I certainly heard some pops and clicks while they played it, as that turntable picked up everything, but I also heard a dead black background, and a completely natural voice and piano coming to me from the speakers. It was more natural than any CD's I've heard, and I'd happily deal with the pops and clicks to hear something that sounds so natural all the time. - ChrisHeinonen Sun, 24 Jan 2010 22:41:15 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-2638 I'm in my mid twenties and I find the pops and clicks of LPs horrendous. I can't stand it. I think people who listen to LPs are crazy. You get rid of them with a $3,000 dollar turntable? I can get rid of them with a $10 CD player. Maybe CD's sound horrible. Maybe they don't capture everything LP's do? You know what? I DON'T CARE you think CDs sound horrible. I fricken enjoy it. Just like you DON'T CARE that I think LPs sound horrible. You fricken enjoy it. Just like 12 year olds DON'T CARE we both think their MP3s sound horrible. They fricken enjoy it. It's all about the fricken enjoyment. Get out there and fricken enjoy your music. This emotion filled/technical detail filled debate drivel is pointless. This is about as stupid as comparing the realism of paintings to photographs. Back to this fascinating article. - Daniel Thu, 21 Jan 2010 10:55:04 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-1677 There has just been a study published that found that most young people tested prefer low bit rate MP3 over higher res formats essentially because they have listened to MP3 so much and for so long that they are accustomed to this sound and even though the "cognescenti" have ruled that it is inferior. I postulate that this also the reason that may people stil prefer the distorted sound of vinyl.... habit. This is a legacy format for anyone over 25 or 30 years of age and the plethora of distortions in vinyl have become a "comfort food" for them. So pick your distortion preference - vinyl or CD. Chacun a son gout! - Bob L Thu, 19 Mar 2009 04:14:00 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-1606 anyone who starts off with the claim that dithering and aliasing of 24-bit audio is actually not a bad thing knows almost nothing about sound and should immediately be ignored. Anyone who thinks that upsampling a compressed 16-bit CD up to a trillion bits will somehow bring back information that was destroyed is fooling himself and needs to watch more upconverted DVDs and compare them to good Blu-Ray. Anyone who makes the blanket statement that vinyl and tube lovers are enjoying the "distortion" of the medium is an imbecile. I enjoy the deeper soundstage, greater resolution, better detail, and more realistic timbre of vinyl. Distortion DOES NOT enhance resolution, detail, timbre, and soundstaging depth. Distortion is nasty, much like most digital sounds. Anyone who thinks that original master digital recordings are anything special needs to learn the basics of how digital recording actually works. Even at the master level, digital recording is horribly flawed and aliased/dithered, whereas analog recordings are not. In the end, you take a flawed digital recording, then compress to it a terribly flawed medium like CD, and then upconvert it through a consumer level DAC (even a $2K DAC), and you STILL think that digital is the better sonic format? LOL. - Blod Thu, 26 Feb 2009 23:22:13 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-1430 Whether or not YOU like the unarguably distinct sound of Vinyl over Digital is a matter of preference, and there cannot be a right answer there. As to which format provides a higher fidelity representation of the original waveform, there is no debate. It's like creationism vs evolution or climate change vs "co2 is good" A bunch of science on one side and a bunch of emotion on the other. - George Sun, 18 Jan 2009 02:16:59 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-1377 Great dialogue. As many have noted, much of this is academic – and of literally no import in the real world, or in my listening room. Let me explain. Both digital and analog have become so good that it’s ridiculous. A strong example of either one can be – literally – breathtaking. Which one you prefer is determined by which one got the larger share of your budget. I’ll give you five-to-one that that every person on this page who says CD is superior spent far more on their digital set-up; every person who prefers analog dropped more on their turntable. To whit: my CD player cost less that $1,000. On the other hand, my turntable – once you add in the cartridge and the fancy-pants interconnects – set me back about three grand. Can you guess which one sounds better? Folks, the complaints are ALL legit. My turntable has some pops. Sometimes a CD sounds a bit tinny. And with more investment, I can make either one sound better than the other. Except for those of us who live in a world of unlimited money (checked your 401-K lately?), this is the only answer of any real-world significance. - Cliff Sun, 04 Jan 2009 06:55:54 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-1129 Anyone who has read this far has learned that high end turntables can be very expensive. Add to that the cost of a suitable tonearm, cartridge and pre pre amp (if you're using the preferred MC cartridge) and you're easily in the 30k plus range. An alternative is the ELP turntable. Not cheap except by these standards, it runs about 10k. Its an elegant approach, playing the LP with laser beams. The record slides in and out on a tray similar to but obviously much larger than a CD tray. The laser beams read a much smaller part of the groove than a cartridge stylus, which is good. Its depth in the groove is adjustable, so that you maybe can find an unworn part of the groove. Obviously the laser beam does not wear the record any further. It also has features that let one track effortlessly to a given cut and adjust turntable speed with CD like remote control. The playing of a record is very different. Clear surface problems can be minimized or even ignored by the laser beam. They claim, and it makes sense but I've never had occasion to try it, that it can play though an actual crack in the record. On the downside, dust which would be pushed aside by a stylus is obviously not. And the dust is "played" with a pop or a tick. Records can not be too clean on this machine. It plays into a normal MM style phone input, no additional preamp needed. And for those digitiphobes, the signal is strictly analog. And last, Micheal Fremer, one of Stereophile's "golden ears" and a vinyl lover, gave it an A rating several years ago, legitimately putting it in the stratospheric range in terms of performance. - Bruce Stram Sat, 11 Oct 2008 03:40:46 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-1123 I own a mastering operation and I cut custom disks for people who want them, as well as masters for production. Through experience before digital, during digital, and now at the full circle stage my $.02 is that analog recordings inherently sound "better" because the technology used to make and reproduce them behaves in respect to response more like our ears do, plain and simple. Digital, on the other hand, now that computers and processors are capable of much higher sample rates than they were when CD's were introduced, can produce results similar to the best analog equipment. Remember at the time CD's were first marketed, we had 'Pong' and 'Ms. Pac Man' not the high end games of today because microprocessors simply weren't capable of handling that much data, especially in a stream as required for audio recording and reproduction. It worked, but not at the level of analog of the time. Fast forward to today, and digital equipment does make a good origination and editing medium at the higher sampling rates - I'd much rather 'cut' and 'paste' than literally, well, cut and paste like we used to. However for a distribution medium, the LP wins because the CD limits frequency response because of the sampling technology available at their introduction which is still the same to this day, and other formats such as SACD or DVD-A are getting closer, but still have limitations and issues as with any format, but lack the character and sound quality of an LP. Disks cut on our system and many others that are being brought back on line around the world to meet the new demand have a sparkle and warmth that digital recording haven't had. As stated with the newer sampling rates available (over 100 kHz) the quality is getting closer and those are the rates we use to originate, then transfer to disk the new recordings we make. Whether original recordings or transfers from tape, we use the high sample rates which have to be busted down to 44.1 to make a CD of the same material (most customers want both formats), and you end up losing information and quality because of that. In my opinion, there really isn't a "which is better" it's more a question of which is the better way to originate and edit, and which is the better way to copy and distribute. Both technologies have good and bad characteristics, but what we've found is that digital work at a high sample rate for origination is a great media to record and master with, but then output to a lacquer disk and you have two winning products. Finally, my recollection of the CD's introduction was mainly to address surface noise as records had been commonplace items for years and were subsequently used and abused. Noiseless recording was finally possible - that was the digital advantage of the time. Somewhat greater dynamics played a part, but I recall most of the emphasis was on noise. If you take care of your records, keep them clean, play them on a good turntable with a good stylus, ground your turntable, and put the vinyl slab back in the sleeve when you're through, you don't have the "ticks and pops" people cried about because they didn't treat their records with respect. Now that CD's are as common as LP's once were, look at what happens when your CD gets damaged. I'd much rather hear a passing click or pop if my disk did get damaged, rather than the d-d-d-d-d-d-d-d-d repeating and subsequent ejecting of a CD when it gets damaged. - E.M. Wed, 08 Oct 2008 18:27:46 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-970 First off, I'll state I'm firmly in the digital measures better and therefore must be better camp. I want to hear the closest account of the original possible, if the recording needed loads of 2nd order harmonics, the engineer's would have added it. I have approx. 1000 albums, so I consider myself very familiar with the vinyl sound. However when I used to play records (back in the 80's), my system did not have the ability to reproduce the lowest octaves. My system today has a pair of SVS Ultra subs, and my speakers are fairly flat down to 35hz. When I recently attempted to play vinyl on this system, I couldn't get any SPL without a violent reaction from the subs, and of course the subs would excite the tonearm and make things worse very quickly. Even at levels low enough to not excite the tonearm, the subsonic noise being reproduced by the subs was enough to make you sick to your stomach....and given the deflection of the woofers, wasting alot of amplifier power as well. In the time of powerful subwoofers how are people dealing with this while playing vinyl? I have all my speakers on a concrete floor, TT as well. I just can't understand how and why people are willing to deal with all the mechanical noise when it can be completely avoided. Needless to say I'll be sticking with digital. - binary rules Mon, 25 Aug 2008 11:25:29 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-911 Mr. badcock, with all due respect, your comparison isn't fair and, for that matter, isn't really relevant. You are comparing turntables made by niche manufacturers to CD players made by mass market manufacturers. There are CD players that are made by niche manufacturers such as Linn (Scotland), Meridian (England), and Krell (USA) that are also made in the same types of factories that pay highly skilled employees well enough to allow for decent living in Western society. Likewise, there are also mass market turntables from AudioTechnica, Stanton, and Gemini that are likely made by those "near slaves" you talk about. You also ask about how the "money you spend reflect your own personal values?" Well, in the case of personal expenditures, you are either an elitist who spends a lot of money on a Bix or a cheapskate who spends little on a Circuit City scratch-n-dent special on a Teac. Either way, you can't win which begs the question: why bring the question of ethical values in the mix since both aren't so separate in that regard? As for relevance, your comment does not contribute to the technical scope of the discussions and, rather, seems as an attack against those who may prefer CD or who may prefer vinyl but acknowledges that it's advantages are due to inherent inaccuracies compared to the original master. - Ashram Thu, 24 Jul 2008 23:09:08 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-904 If 12 kHz running through analog to digital conversion is so bad across the board, what's the performance of 12 kHz running through an analog to analog converter when it's the kind that converts electrical signal to mechanical groove? Since it costs about the same as a CD or LP, I suggest any audiophile visit an audiologist or hearing aid supplier with a special request of extending measurement of each ear's sensitivity to 12 kHz. On Apr 29 I posted a link showing 48 to 44.1 converter performance. Here's another more comprehensive one showing huge differences between 96 to 44.1 converters: http://src.infinitewave.ca/ The default graphs showing sweeps should have a completely dark background and no "tail" at the upper end. There is a 1 kHz test from the pull-down menu. Note that the scale goes to about -185 dB. The point again is that without knowing whhat's in a randomly selected recording chain other than how bad its weakest link is, talking about everything else in it has no point. - Nick P. Wed, 23 Jul 2008 13:24:29 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-898 Most quality turntables are made in Germany (Clearaudio), United States (Sota), England (Rega), and made in factories that support their employees enough to have families. Consider where most CD players are made... by near slaves living lives that are at best difficult by most western standards, and typically working much longer days and more days a week. Much of the vinyl thing is more than a sound thing; it is a quality and lifestyle issue. Myself; I am proud to see my audio devices produced by craftsman as compared to low wage fast food type drones. Naturally, this will sound different to some people. Besides, aren't CDs nice and shiny? Pretty, pretty. You can even see your reflection in them. Does the money you spend reflect your own personal values? I give the CD 5-10 more years as a medium. The LP? Ha, it will still be around in 50. - Robert Badcock Mon, 21 Jul 2008 22:46:07 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-891 I do have a few questions regarding the source. Aren't analog master tapes typically loaded with second order distortion? Wouldn't that mean that an exact copy of the tape would also contain significant second order distortion? Wouldn't this also mean that a vinyl copy of an analog tape would be adding second order to second order? Wouldn't this also mean that a pure digital recording that never touched tape and went straight to disc would have the lowest distortion currently available, and technically the best sound? - JM Wed, 16 Jul 2008 09:41:09 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-890 John, I am just reiterating what Tom stated in the question and answer session found in Sound and Vision. Not sure of his pedigree, but I thought that he graduated from MIT. He claims that the signal at 12K is clearly altered. I suppose I am more inclined to believe the opinion of an engineer, producer, guitarist, recording engineer, mastering engineer, etc. more than that of most others. To imply that engineering, sound engineering, is somehow static, I think is not quite right. Obviously, as we gain the capacity to measure the phenomena, we come to new understandings. Quantum mechanics makes proposals much different than those that I learned in Chemistry, and I am not that old. I am not sure how Tom might be measuring the signal, and I don't know that we can necessarily ask him to explain further. Note, however, JEJ's comment seems to reaffirm Tom's contention. I often see these types of comments from musicians. - JM Wed, 16 Jul 2008 09:31:23 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-889 I haven't listened to any LPs that were mastered from a digital recording. I suppose I will eventually, but right now, I have my hands full just trying to decipher the differences between LPs from analog tapes and CDs. Funny you should mention cymbals, because I hear a very big difference with that instrument between the LP and CD versions (analog tape master). I play drums, and the LP version of cymbals sounds much more realistic. - JEJ Wed, 16 Jul 2008 07:26:36 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-886 JM: I'm curious, was Tom Scholz not in attendance in engineering school when they taught the Nyquist/Shannon Sampling Theorems? This isn't exactly new stuff here, it dates back to the first half of the 20th century. Were Mr. Scholz in engineering training in the 1920s he would be celebrating his 100th birthday very soon, and not a member of Boston in the 1970s. A 12K fundamental will pass completely unaltered by the process with a 44.1K sampling rate. This will then be exactly reproduced at the output following the output filter. Realistically, most signals are not pure sine waves, and any harmonic of a 12K fundamental will be above the input low-pass filter of the analog system. That said, I don't know of many signals in music that have a 12K fundamental. The highest note on a piano is just under 4200 Hz if we are using an A4 = 440Hz tuning. You'd have to be above the 3rd order for this to be skipped by an output LPF. This exceeds the range of all musical instrument fundamentals in western music. I'm sorry, I'm not quite as knowledgeable about eastern music to discuss that with any significant level of detail. So we have every instruments fundamental covered -- with the noted exception of a few percussion instruments, of greatest interest which would be the cymbal and the triangle. There are also intentional colorations of some instruments such as a harmon muted trumpet which can produce content above 20K. It should be noted that the harmon muted trumpet produces less than 2% of its energy above 20K. This would only hold true for close-in mic'ing of the instruments however. Once you get out to more along the lines of 5-8 feet the ultrasonics become almost immeasurable. I would be remiss if I did not point out that 2nd order distortion is highly euphonic, it occurs at an exact frequency doubling of the fundamental, which is a much richer sound than the raw fundamental. Try this experiment -- play a middle C on piano. Now play a middle C a very light High C. Guess which sounds richer? Guess what 2nd order distortion does? It will reinforce at octave intervals all the way up the chain. So, you get 2nd order distortion of the fundamental, 2nd order, 3rd order ad infinitum -- or at least to the limits of the system. That this is a distortion cannot be argued. Whether or not one finds that distortion to be euphonic is quite another issue entirely, but it is (ipso facto) not accurate to the source. - John Kotches Tue, 15 Jul 2008 18:43:25 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-885 I am not sure that the point that he was trying to make was that there was an anomaly at 12K. I believe that the point was that a 16/44 conversion distorts the waveform in general. He chose 12K because he noted that this is a frequency that most of us can hear. He also noted the affect on cymbals, violins, and even electric guitars. Not good and audible. Sadly, there are number of records available that were mastered from digital sources, even cds. Some were even mastered from downloads. Why not measure those. I suspect that your findings will not vary, but I don't really know. Then listen and compare the vinyl and cd version. When we ran this latter test, and we found ourselves typically preferring the cd version. Vinyl second order distortion may well exist, but it couldn't mask the problems with digital very well. Absolutely no one preferred the cd version to any pure analog equivalent. - JM Tue, 15 Jul 2008 16:07:47 +0100 http://www.hometheaterhifi.com/technical-articles/426-a-secrets-technical-article.html#comment-882 The bottom line for the sound is the original signal along with whatever distortion spectrum comes out along with it. For the vinyl, if all that comes out is the original, plus second order harmonics, plus noise, then that is all there is to make the sound. There is no magic invisible component. Everything in the electronic signal that makes the sound is measurable. There may be a 12 kHz problem in the D/A conversion, and there appears to be a 5 kHz problem with Class A operation, but it is all measurable. There could be IM differences with LPs, but I can't find a test LP with IM test tones, such as 250-8020 Hz or 50-7000 Hz. I would suggest 50-7000 Hz, recorded at - 20 dB and 0 dB, in both channels simultaneously, each channel individually, and also with 50 Hz in one channel and 7000 Hz in the other channel. We also need LP tracks with frequency sweeps in steps rather than continuous, because an Audio Precision test instrument requires stepped sweeps. Perhaps 60 steps, 2 seconds each, from 10 Hz to 30 kHz. Also, maybe an additional stepped frequency sweep with no RIAA curve applied. That would let us measure the frequency response directly from the cartridge, although it might only work with high output cartridges. Maybe there are some problems with certain frequencies in vinyl, like the 12 kHz issue in D/A conversion and 5 kHz issue in Class A. That is the purpose of our article series. We are trying to find out what the differences are. - JEJ Tue, 15 Jul 2008 07:47:37 +0100