I think there have been a couple of misunderstandings, but also there will be a few things we disagree on. Such as whether re-copying the demos is even worth while. I'll try to go in order based on your reply. You're right, I didn't get that saturnine was talking about the original recordings. Although I do know that recordings are made on several tracks for the purpose of mixing and editing, I just didn't see how it could matter. But yes, the quality of the Matt Good demo was not likely to be first-rate, after all it was just a demo, right? I think I can glean that from the mp3s of the songs. Remember I said that they were heavy on the treble.
About the reason I want to make copies at the high sample and bit rates, the goal was less for obtaining lost high frequency response and more to obtain accuracy and details. I look at it like there are two things that aren't great about the mp3s: They are mp3, which means the treble response is characteristic of all mp3 sounds in that it has a warbling, chopped and reconstructed sound to it, though admittedly it is less dramatic then I make it sound. The other is that the sample rate of the recordings is 44.1KHz. Standard cd quality, but inadequate for obtaining undistorted copies of the sound. I think this leads to the next section.
Do we know what sort of a deck and DAC were used to convert the demos to cd and then mp3? Let me say that despite all this talk of high sample rates and bit rates and such, that I would in fact be happy with obtaining cd-quality versions of this demo tape. It would at least do away with the compression sound the mp3s introduce. Plus it would have adequate response. Most of my music collection is cd quality, and I keep it on my computer with lossless compression so I don't hear anomalies and so it is still editable without losing a generation of quality.
Thankfully my hardware does seem to be up to the task of recording in two channels at 192KHz with a 32bit rate. Four channels is limited to 96KHz at 24bit rate. This is just the digital I'm talking about, I am aware that the amplifiers (pre-in and output) are nowhere near top quality. They are just class C or D amplifiers I'm sure for the sake of power efficiency and to reduce costs. It's ghastly really - the things those kinds of amps do to the sound is awful! But I make do with what I have, and the digital side it seems is okay. Not, as you say, as good as professional equipment, but I have spent many hours listening closely to the recordings I've made at the maximum resolution when editing out noise from vinyl and I can say there have been no noticeable skips or jumps, however minute. I also had a good close look at the individual samples as I zoomed in to manually remove clicks, and the sound form was definitely not upsampled from 96KHz. The DAC is made by Intel under the name HD Audio. I know this introduces it's own cheapness to the quality of sound, but the resolution is certainly high and the results with recordings of almost previously unplayed Philips vinyl of classical pressed in the early 70's is very nice. The sound is close enough to the original vinyl that I can barely tell the difference, and I think the remaining indicator is the fact that the laptop's amp is being used as a pre-out.
Just looked back at your post and the part about recording silence. I have recorded silence and there is indeed a slight noise. By slight I mean that it is too low for my receiver at home to duplicate at full volume. (The receiver is a modestly powered Sansui G5500). I only know it's there when I zoom in until I can see the individual samples; it's very low and doesn't register on the vu meters in Audacity. I have read somewhere that the electrical noise can't be eliminated entirely from DACs, even when the chip has been well grounded.
Ideally I would have a better quality DAC that connects via usb or firewire. One that handles the same high sample rate but on four channels simultaneously would be awesome - my dad and I have a quad receiver we could hook up again. Ah the 70's....
Okay moving along here... About the differences between cd and cassette, I think you might be incorporating other things than sound quality in the argument for cd's. What cd's offer for the most part is convenience. Much much more practical to have a cd to take along or copy to computer than a tape! And yes, tapes do age. But I was talking about the quality of the sound. Okay, tape has a background hiss. A generation is lost when duplicated or even played back. But a high quality recording on a high quality cassette has a more accurate reproduction of high frequencies when played on high quality equipment than the best cds on high quality equipment - I admit though that that is my opinion, and it may even be mine alone. My argument is this: The artifacts and distortion introduced by tape are sort of akin to that introduced by tube valves in amplifiers: It still has all the high frequencies, it still has almost all of the detail, and it sounds good. The artifacts and distortion introduced by cd digital is different. No background noise, which is awesome, but the sound lacks the frequency range and detail, at least in the upper treble range. Do we always hear this? No. Compare the two, assuming both the cassette and cd are as accurate a duplication of the original as possible, and I find the cassette sounds better.
But not by much. We are dealing with admittedly small points that, as you say, most people don't notice let alone care about. The old cassettes I have that are dying are not worth copying to digital. I only copy cassettes that have content that isn't available, such as one I copied a couple of years ago that was a copy of a copy of a radio broadcast by the CBC of a jazz band called the Rainbow Gardens Jazz Orchestra. I've since found an unplayed record by them and copied it to high resolution digital. Rare stuff. Anyway, the reason my tapes are all dying is because they were indeed poor quality. Very few pre-recorded tapes were made to good standards. Philips classical was an exception. On the other hand Denon made the very best broadcast cassettess from the 70's to the early 90's, and those are still just fine after all this time. My dad still has a few from when he worked in Radio and they are only just beginning to deteriorate in sound, but mechanically they are still good.
That reminds me - you ever want to hear tape that will give cd a run for it's money hunt up a broadcast Akai reel-to-reel and get some 1-inch tape platters! Wow! The bandwidth and detail are hard to beat.
Just reread part of your post, about mixing down to 44.1 or 48k digital after recording to tape during a session. I agree that that limits the detail available to copy from the demo tape, but - this is just a hypothetical here - would copying a tape whose source was 48k to digital at 48k not introduce some odd sounds where the sample rates didn't align? I guess the tape would sort of suppress that.
Finally, I realize cd is here to stay for a while yet, and that there are compelling reasons besides the fact that it's a very widely adopted standard. I'm saying that higher resolutions are now available for a lot less money than ever before, and that the resulting definition would benefit a number of people who can tell the difference, or who want to edit and modify the sound and require more detail. Musicians perhaps? People who play with the sounds as much as members of Massive Attack might find the extra resolution gives them more freedom to alter the sound of their compositions. But ultimately I came here to seek out someone with a copy of an old demo so that I could see what detail I could squeeze out of it while hopefully preserving it in a lossless digital format. Even if it's just cd resolution it would be nice to have.
I hope I haven't come across as a snob or a jerk. If anybody has a tape or cd copy of the demo please consider allowing me to copy it. Sorry I can't offer money compensation - I would if I was better off these days. In any case, I hope everybody has a good valentine's day ;) Thanks for your time.