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Post by Deleted on Oct 8, 2012 20:24:58 GMT
If it happens I expect they will be off a Status Quo album. or "Whatever You Want" You'll have Mike after you!
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Post by Deleted on Oct 8, 2012 21:24:14 GMT
Marc There shouldn't be any need to sacrifice a CD-R. EAC has often said to me something like "this CD can be used for calibration" Alex
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XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
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Post by XTRProf on Oct 9, 2012 0:01:29 GMT
File: AMD - Track03.wav CRC-32: 66f2058b MD4: c191843280dabe4bcc23df1da488f2a8 MD5: 0c07c6782e8d000799cc38cdb54113b4 SHA-1: 17110a3f9cdea92f46b93c9016b9b605fbde540d File: T60 - Track03.wav CRC-32: c7513c97 MD4: 1f6d2d51a2d1759545e4dc3080674a6e MD5: 6a874d20672cf92396f73a00e3183bfa SHA-1: b6089c3c5ee15bba84a14764df4c13d9762c8e63 May I know are the 2 EAC comparsion checksums on the same PC the same after rip although the checksums are different on the 2 PCs? As for CD writing I have number of Yamaha drives with AMQR. I have done comparisons and always found the AMQR setting to result in better reads. It increases the landing point on the pits at the expense of reduced CD run time. This makes it easier for the disk to be read. I would suggest everyone who burns their own CD compilations gets one of those drives or the Plextor equivalent. I await constructive comments !!!. Interesting. So are you suggesting Yamaha and Plextor are the best for ripping CDs? AMQR is only availble on these drives? If that's the case I will get them for purely ripping CDs. What do you think of Samsung writer since you have used lots of writers. Thanks.
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Post by Deleted on Oct 9, 2012 0:35:34 GMT
Ah, no, i'm not stating either way. I still believe it could be possible that identical checksummed files could sound different (based on the statements on RG). I was just explaining why you could have different checksums on the same tracks, ripped on different PC's. If you did the offset calibration, then they should still sound the same as before, but you would have 2 identical files, sounding different. As an aside, I have a compilation CD that I made in 2005 on a previous PC. Although the various tracks were originally ripped using an earlier version of EAC and reported to be error free, they sound woeful after being ripped again, in comparison with fresh rips of those tracks from the same CDs using an internal LG BR writer. Checksums are of course different, so this offers no real proof. If anybody else has old CDs made using an earlier PC, why not try ripping the same tracks on your present PC , and reripping the old CD to see if they sound the same. If EAC said there were no errors at the time of ripping originally,does it really matter if the difference in checksums were due to a couple of non noticed minor errrors, perhaps even due to lead in differences , or a couple of corrected errors ? According to present theory it should NOT result in any real SQ differences between those tracks when played back, or ripped again. As far as I am concerned bit perfect means 5/8 of SFA in this scenario. Alex
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Post by freddypipsqueek on Oct 9, 2012 8:09:22 GMT
AMQR is for writing CDs (see www.yamahamultimedia.com/yec/tech/aam_01.asp). I have found it produces better disks sound quality wise though my tests at the time were using a Sony CDR227ESD and not reading via a PC. I do rate the Yamaha drives for reading but my opinion is mainly based upon their ability to read disks other drives cannot. CDRInfo used to review the reading performance of CD drives but this is not now important (e.g. www.cdrinfo.com/sections/reviews/specific.aspx?ArticleId=5126&PageId=2). Plextors have the best reputation for reading but I have not tried one. On Plextors the technology is not called AMQR but I have read that similar settings are available in plextools. I would recommend that everyone gets a Yamaha AMQR drive and I have found the older external USB units are just as good as the later internal ones; the technology did not change just the writing speeds. I ripped the tracks twice on each machine and got the same checksum. I don't understand checksums well enough but now assume they are individual to each machine and I'm also of the view that both rips (on each machine) were identical. I am not yet entirely sure that the AMD & T60 rips were the same but the data comparison suggest (strongly) they were. I could not tell any difference in sound quality (if there was one) for me to care. I am tempted to pick a single PC and see if stripping it down in hardware and software changes things. It is a long task though. I picked the 2 computers involved because they were at the extremes of my collection. The AMD is loaded and messy and the T60 already stripped down for CPlay. On the software front (and important in my thinking) removing unwanted windows files from the T60 made a noticeable difference in CPlay playback quality. I have not seen any improvement in the "data" reading of the CDs however. Finally I have tried two versions of EAC (.99 & 1) and found the checksums the same. It doesn't follow however that other software or versions will not be different. I am in agreement that CD reading performance may well have improved over time. Again I do not know the technology well enough but I am guessing that whilst CD data reading is verified with checksums and CRC etc, with audio there remains the possibility for misreads; I have one Kate Bush track which was extracted from a scratched CD including significant playback errors. This cannot have been read with any form of checksum or finite error correction. I also wonder if a Blueray writer, with the tolerances involved to write such large disks, finds reading CDs a doddle and thus is more accurate. The jury is still out.
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Deleted
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Post by Deleted on Oct 9, 2012 8:30:06 GMT
Adrian That is incorrect. If the writers are calibrated to the EAC server using the same version of EAC, then the rips should have identical check sums. As an example, I did a series of comparison tests with C.A. member "silverlight" from NYC. One of Geoff's favourite tracks was "Feelin' the Same Way-Norah Jones." We both had the same Hybrid SACD. Not only did we end up with the same checksums for that track, but Geoff said that my rip sounded better than his, and that was before we started sending the .wav files as uncompressed Zips to reduce Filemail server degradation. I also did some tests using Fidelizer. The improvement resulting from using Fidelizer has also been verified in tests involving Marcin, who is a co-developer of the jPlay software for Windows, and John Kenny.
Some time back, Terry O from DIYAudio posted some high resolution scans of the surface of a disc written by a BluRay writer. The pits were far more precise than with normal CD writers. That is why I have 2 LG BR writers, and at least 6 other RG members own LG BR writers.They do have separate lasers, but I believe that the laser assembly is likely to be built to closer tolerances, and the tracking mechanism likely to be superior too.
If you check the cPlay website, you will find that they recommend doing that, jPlay likewise, in fact we also did some rip tests withJ.K. and Marcin using Fidelizer. That is also the reason why I use W7 in Safe Mode for the best quality rips and conversions from .high res .flac DLs to .wav
Regards Alex
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Post by freddypipsqueek on Oct 9, 2012 9:19:33 GMT
I did not calibrate the drives with EAC (Accuraterip). Calibrating the drive gets a checksum from a database and should remove any variances unless you don't believe in checksums (don't answer that). In the case of the T60 the machine has no internet access (to reduce overheads) and thus reference to a server was not possible. In a way I was looking for variances in the rips to see if they affected the sound quality of the rips. To me I did not find any and they did not.
In your tests did Geoff use a different reader and even though he gets the same checksum what accuracy figure, and other readings, did EAC give on completion ??.
I understand your conclusions but my rough and ready approach has not (yet) been able to verify them. You guys may have been able to hear a difference but I have not and I have found no evidence to tell me the files are not the same and thus I am right to conclude they sound the same.
Your points about Blueray players are noted and understood. They make a lot sense to me.
I have checked the Cplay site and spent hours stripping software off machines. A netbook or laptop is ideal - I my case the IBM T60 and better still an IBM X60. It is because of this point that the T60 was an ideal comparator (particularly as it could be battery driven and had an internal CD drive). I couldn't think of a more cut down machine. I have not yet however been able to find a different between the T60 and the AMD for ripping whereas for playback they are in a (totally) different league.
It maybe that your views are correct. It is possible that there are differences. I am not convinced however and in any event I am getting to the view that, if there are, they are too small for me to value them enough.
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Post by Deleted on Oct 9, 2012 9:32:17 GMT
Geoff used a different writer to me. IIRC, we just saw "accurately ripped"which I presume was confirmed by EAC checking with the online database. That would have been around 2 or more years ago now.Geoff purchased an expensive external BluRay writer as a result of our tests P.S. I had to believe in checksums, as I was responsible for a group of Processor Controlled LME ARE11 Telephone Exchanges, and duplicated stores where the checksums no longer matched resulted in quite a few after hours call outs. Attachments:
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