the definative cd lathe test

So who sells these lathes ?

 

I must pick this point up.

Rob says that a 'lathed' disc is visibly different from a non-lathed one. Do you agree that this is the case?

 

This is inarguably the case - the lathed disc has a blackened and bevelled edge

 

agreed lathed disc is apparent.

I was assuming that the listener knows which file is lathed and which not, so dont waste your pedanticity on me please.


If the tests are blind there is no reason why the results should be different, and if not blind there is no reason why they should not be affected equally by bias.

 

Hi Sq - I quite agree.

I rather suspect however, that sending discs to forumites (if that is a word) - few will be doing 'blind comparisons' - rather more likely they will swap them from one to t'other and make a sighted comparison.

I feel this is not due to any wish to prejudice the results, rather that wives and girlfriends etc will not be the least bit interested in disc swapping ... looking on it as some sort of fetish.


I am just waiting for the results of that to happen..

 

Careful, SQ, telling it like it is doesn't half get up peoples noses!

Chris

 

Chris, it's often difficult to get the tone across in online posts, I'm generally lighth-hearted with a hint of don't give a **** if i upset anyone.

 

many thanks for the speedy return of the cd's ..and the interesting listening notes ..

will forward these disc's on hopefully tomorrow ...latest monday

 

lbr, what is track 5 on those discs? I quite like it

 

Sorry, I pulled together a bunch of random tracks and can't remember what was on there now. Can you post up a snippet of the track - I'm sure I'd be able to ID it then?

 

Perhaps it is definitive after all!

Pete kindly posted me the discs which I listened to last night.

On the first playing I thought the lathed disc sounded a tad smoother, just like it had with the CDR test. However after repeating the test several times the results became random.
I can only conclude that using my ears in a sighted test there is no difference.

Next, using the same Meridian 206 via optical out I recorded track 1 from both discs into Audacity, inverted one file and mixed them.
The result as you can see is a perfectly flat line.
Therefore the output from the Meridian using these disc is identical - 100% perfect and they cannot possibly sound different.

If you want to hear the null track a link appears below, but honestly, you will just hear complete silence - not so much as a tick!

Here is the screen shot.
Top shows the two discs with one inverted, bottom shows them mixed together.








Wav file:

http://www.mediafire.com/download.php?tjummwtlmwl


Happy to supply the source files to anyone for verification.

 

Lovely - well done Rob. Not only is ther eno difference, but even old transports are sufficiently 'bit perfect'.

Which may not be the end of discussion for transports , of course, but is a certain vindication of some fundamentals.

 

Yes thank you Rob, good job.

 

A lovely test

Interesting to note also, that the issues with the other null test was either due to non-perfect CD-R recording, or as Martin suggested, some sort of electrical interference like a thermostat.

 

Actually what that proves is that with this cd player and these discs that the cd lathe has no apparent effect on the sound. You can't extend that finding to all lathed discs and all transports without trying them.

Though it may or may not be a reasonable assumption to make...

 

Reasonable to assume that lathing might perhaps be of benefit on a poor or part faulty transport (or poorer than the Meridian).
The Meridian 206 dates form the 1980s and has the old CDM4 mech, and never been serviced.

 

Lathing certainly improved my discs.

No question about it.

Whether that means my A5's transport is ****, don't know.

 

Perhaps.

But I've now seen and heard enough to put the idea to bed, permanently.

 

It's also well worth searching this forum for posts by Tones on this one. He understands the materials and manufacturing processes involved in CD production and maintains that removing the edge from the disk runs a real risk of oxidising the aluminium layer and therefore ruining the disk over time. This is enough of a doubt for me to avoid the whole thing; some tweak that even the golden-eared can't agree makes a difference is just not worth risking buggering up your music collection for. As a second hand vinyl & CD dealer I'd be very reluctant indeed to buy in disks that had been 'lathed', I'd certainly pay a hell of a lot less for them.

Tony.

 

They are worth a hell of a lot less now any way!!

I, too, considered Tones's (Tones'???) arguements fairly thoroughly before going down this route.

The sonic differences were, for me, sufficiently great, coupled with the fact that CD are generally coming down in price, It took the/a gamble.

Time will tell whether I was right or not, but so far so good.

Not golden eared especially, Tony btw , I just liked what heared .