Popular Post gmgraves Posted October 14, 2018 Popular Post Share Posted October 14, 2018 On 10/11/2018 at 6:23 AM, Geeksterlab said: Enquête : Vinyle (bonne qualité), vs DSD256 natif? Merci pour votre participation ! As a format, Native DSD wins. In fact, as a format under any circumstances, DSD wins. Vinyl has many problems. First of all, while it is possible to inscribe frequencies up to 50KHz onto a vinyl record, as JVC found out with their multiplexed "quadraphonic" scheme, CD-4, even when using special vinyl compounds and special cartridges with special stylus shapes (Shibata), the 30 KHz subcarrier simply did not last for very many plays. Secondly, even under the best of conditions, vinyl struggles to obtain a dynamic range of 60 dB, and that's when pristine, new, out of the sleeve using top-grade virgin vinyl. Then of course, there are the various manufacturing defects: Off-center holes, warped discs, under-fill (where the vinyl "puck" did not evenly fill the record mold), noisy "regrind" (where formerly made and not sold records are reground to add to the vinyl mix for a new batch of records), etc. Add to that the fact that records cut from analog masters have very little on them above 15 KHz (that's the limit of the ability to maintain analog tape recorders due to the limitations in tape head alignment and the inevitable self-erasure of high frequencies on the tapes). Then, of course, there's the inevitable slow decline of the record as it is played over and over again. Records can last for decades, I have some that are more than 50 years old. And while they are still playable and enjoyable, when compared to a CD or a high-res LPCM download of the same material, it is obvious that some of the "sparkle" on the top end is gone and that the vinyl version is us unmistakably very noisy in comparison. In spite of those serious shortcomings vinyl has a number of euphonic colorations that make the sound of a vinyl LP very serendipitously musical. That's not to say that it's accurate to the master tape; it can't be. Most people are totally unaware of the artistry and craftsmanship that go into mastering an LP. It's not easy and it's not straightforward. First of all, there's the cutting head. This thing is sort of a phono cartridge in reverse. it takes the incoming signal and converts it to a physical representation of that signal by causing the cutting stylus to trace that signal onto the blank lacquer disc. The lacquer may be soft, but it's not THAT soft. The cutting stylus has to have a lot of power behind it to allow it to keep-up with a signal comprised of frequencies from 20 Hz to 15 KHz. So, high power amplifiers are used to drive the cutting head. In the early stereo days when Mercury was recording those still beloved "Living Presence" recordings Mercury used two 60 WPC McIntosh amps to drive their Westrex brand cutting heads. Since then of course, complete recording lathe setups have been available turn-key from companies like Neumann, JVC, and Ortofon using sold-state amps of varying power and design. Most lathes use Ortofon heads, mostly because they have service facilities here in the States and in Europe. They can turn a blown or damaged cutting head around in hours. Cutting heads use so much power, and are so inefficient that virtually all professional cutter heads are water cooled. It is axiomatic of a cutter head that they have very little dynamic range and require a great many Watts to start them moving at all, and just a few more to burn one out. How can something with so little dynamic range cut a record with 55 dB+ of dynamic range? The answer is the skill of the mastering engineer coupled with the RIAA eq curve. Modern cutting rigs have automatic pitch control, whereby loud passages result in fewer grooves per inch, and soft passages result in more grooves per inch. That was controlled, in the past, by a read head on the mastering tape that was positioned by some fixed advance in front of the head providing the actual record signal. The advanced head told the lathe carriage whether to widen or narrow the pitch in advance of the actual record signal reaching the cutting head itself! Today, the advance head is replaced by digital delay circuitry to delay the musical signal by the interval needed to control the pitch of the grooves. Finally, record cutters need ultrasonic filters to keep-out UHF signals and oscillations which could blow the cutter and acceleration limiters to keep the cutter head from trying to move too fast and too far thus avoiding the stylus cutting through the "lands" into an adjacent groove which would ruin the entire master. It's a wonder that we consumers end-up with anything listenable at all!. Digital is both easier and better, but again, Just as it's possible to make to a lousy LP, it's possible to make a lousy DSD, CD, or LPCM download or music Blu-Ray! It's all in the care and execution at each step of the process. sandyk, Sam Lord and Ralf11 1 2 George Link to comment
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