Hey: I looked at one of your close-up pics and that reminded me. While you're at it, could you also be sure to clean the stylus with a Magic Eraser before each play, if you can? Just lightly press the Eraser to the stylus in an up/down motion to get all the gunk off. It's the cleaning method du jour nowadays and it's pretty cheap. It really can improve some of the results.If you don't have a ME then a useful alternative is a Q-Tip soaked in rubbing alcohol, but you have to be sure not to get the cantilever too wet as it can wick up to the suspension, and some stylus adhesives do not like getting wet (but that's usually a problem with the high-end carts more than the entry-level ones).
The 1 kHz test sample and Dum Diddly (LP) don't work for me
Also the links for the Gorillaz and Black Eyed Peas samples are all kinds of messed up.
Off the cuff, the bass boost is pretty shocking, to the point that I'm not exactly sure if it could even be caused by a tonearm resonance problem - it might be a mastering change on the LP. It's around 30db@50hz ish.
Hey: I looked at one of your close-up pics and that reminded me. While you're at it, could you also be sure to clean the stylus with a Magic Eraser before each play, if you can?
...amazing how much gunk it could pick up from just one play, depending on the disc.
I only listened to the Steely Dan clips so far, and it made me not miss vinyl. ;> (To be fair, I think the LP version might sound better with some level-matching to the CD version )
Bad news, krab... they're already level-matched.
That was my impression too just by listening to the Gorillaz LP sample vs. the CD. These should be the same masters since the album was put out in 2005.
These are all new LPs, so there should be minimal gunk
Quote from: krabapple on 18 February, 2009, 12:29:36 PMI only listened to the Steely Dan clips so far, and it made me not miss vinyl. ;> (To be fair, I think the LP version might sound better with some level-matching to the CD version )The original plan was to keep match the levels as best as possible. Then I discovered that the USB turntables I'm testing don't allow me to set the levels!I could normalize after the fact but I don't want to give the impression that the samples have been tampered with.
QuoteThese are all new LPs, so there should be minimal gunk.Vinylphiles IME commonly recommend a thorough vaccuum/clean of even brand-new LPs. Maybe it's just one of their rituals, but isn't there supposed to be some kind of 'releasing agent' on new LPs (artifact of the stamping process)?
EDIT: -- hold on -- the Dark Side clips yield the same replaygain value (+1.24 dB) ..but the Dan clips do notHome at Last LP -0.22 dBHome at Last CD -2.88 dB
Magic Eraser is a sponge, not a marker - it's going to be in the cleaning aisle.
Vinylphiles IME commonly recommend a thorough vacuum/clean of even brand-new LPs.
New pics up for Pink Floyd and Steely Dan samples, check the upload thread for the images and details....
It's hard to derive any more from these plots without probably equivalent masters and/or the test record sweeps.
I did pick up the old, reliable Discwasher system, though. I'll clean the test LP, ME the stylus and then post another sample of the silent groove.
That brings up a good question: Which specific tracks make for the best samples? You can read the track list and details for Ultimate and Hi-Fi News are online. Here's what I'm considering:[blockquote]UltimateSide A, Track 1: 1kHz tone (Done)Side A, Track 10: Wow & Flutter test SignalSide B, Track 1: Anti-skating Test, 315Hz sweep to +12dBSide B, Track 4: 1kHz vertical, out-of-phase signalSide B, Track 5: 1kHz to 10Hz sweep at -20dB, verticalSide B, Track 6: Silent groove (will re-do after cleaning)Hi-Fi NewsSide B, Track 7: 20Hz to 20,000Hz sweep[/blockquote]Will that do it or are there any other important tracks? Are there any I shouldn't bother with?
Quote from: Knowzy on 19 February, 2009, 11:27:20 PMI did pick up the old, reliable Discwasher system, though. I'll clean the test LP, ME the stylus and then post another sample of the silent groove.Take that sh*t back
First of all, IMHO, don't clean the test records unless you can see specific issues with them that require cleaning. You're putting a lot of trust into the cleaner to not negatively affect the test record results...
Second, just post the entire needledrops of Ultimate and HFNRR. I can use almost all of the former and most of the latter.
And when you're done with all the tables, please re-record each test record with the first turntable you played it on, to establish how much the results changed as a result of all the plays.
Those are pretty, but they're not remotely resolving enough....Your frequency and time resolution should both be at least a hundred times more greater to get useful results, and that level of detail is simply impossible with spectrograms.
The reference for interpreting wow/flutter is Poul Ladegaard's legendary 1977 paper on mechanical resonances. Specifically look at Fig. 18 on page 7. Those are the sorts of charts you ought to be displaying/interpreting.
I've been meaning to cook up a good quadrature demodulation program for some time, and now is the perfect time.