What would cause distortion in certain CD's

markC · « **on:** 21 Mar 2004, 04:21 am »

I'm getting distortion in the upper frequncy of cetain cd's, (such as Nohra Jones, Stacey Kent and Sahra Mcglaughland). I have always thought that it was the cd itself, but after switching amps,pre and speaks, it is obvious that the constant is my QDS-15,(Nohr CD1) cdp. Other great sounding discs such as Diana Krall, Holly Cole, Mark Knopfler, etc. are fine. Any thoughts??? The distortion sounds like a sssss on vocals.

Tonto Yoder · « **Reply #1 on:** 21 Mar 2004, 06:35 am »

One thought: just because the CD player has been a constant throughout amp/pre etc. switching DOESN'T necessarily mean that the CD itself isn't at fault. The fact that the Cole/Krall/ Knopfler sonics are fine suggests it MAY not be the player's fault. If you were able to audition another player in your system and Norah Jones wasn't sibilant, then the CD player would definitely be the culprit.

What about rolling tubes in the Norh??? That helped me enjoy my own tubed CD player--switching from the stock tubes to fairly warm-sounding Amperex Globes. I wouldn't have described the stock sonics as "distorted" but they could be a tad bright, and the change of tubes made everything sound better (i.e. less fatiguing, more musical etc).

Mad DOg · « **Reply #2 on:** 21 Mar 2004, 11:14 am »

Quote from: Tonto Yoder

One thought: just because the CD player has been a constant throughout amp/pre etc. switching DOESN'T necessarily mean that the CD itself isn't at fault. The fact that the Cole/Krall/ Knopfler sonics are fine suggests it MAY not be the player's fault. If you were able to audition another player in your system and Norah Jones wasn't sibilant, then the CD player would definitely be the culprit...

i'd agree w/ tonto here...the cd recording isn't always perfect, but you need to compare your cdp w/ another that doesn't exhibit the same silbilance to know for sure...

Agrippa · « **Reply #3 on:** 21 Mar 2004, 12:20 pm »

What about the copy protection on those discs? Of the ones you mention, I only know Norah Jones, which I know is protected and has wreaked havoc with a lot of players...

Seems rather unlikely to me that you should experience this with only a few discs, unless the discs themselves are at fault. And if the discs are indeed at fault, then copy protection is certainly the most likely and most frequent perpetrator.

Try burning copies of the offending discs if you can and see if that solves the problem. If so, you know where the problem lies.

Agrippa

bundee1 · « **Reply #4 on:** 21 Mar 2004, 02:48 pm »

Anyone considered that maybe the discs are compressed and have the highs clipped off. This maybe causing the distortion. I know its like that on the 2 disc Fleetwood Mac greatest hits and the Doors 2 disc legacy.

markC · « **Reply #5 on:** 21 Mar 2004, 02:55 pm »

I've tried the offending cd's in my second system with a fairly cheap Panasonic DVD player as the source. No problem, other than the comparable sound quality. As far as tube rolling goes, I've done lots of that and am currently running a pair of CAA black plate Sylvania 5751's-love the sound of these. I remember the same problem when I first bought the Stacy Kent disc and I think I had Svetlana 12ax7's in the player at the time. Burning a copy of the disc sounds like a good idea. I'll head over to a friends this aft and burn a copy. Thanks for the suggestions.

Jon L · « **Reply #6 on:** 21 Mar 2004, 06:48 pm »

Quote from: markC

I've tried the offending cd's in my second system with a fairly cheap Panasonic DVD player as the source. No problem, other than the comparable sound quality. As far as tube rolling goes, I've done lots of that and am currently running a pair of CAA black plate Sylvania 5751's-love the sound of these. I remember the same problem when I first bought the Stacy Kent disc and I think I had Svetlana 12ax7's in the player at the time. Burning a copy of the disc sounds like a good idea. I'll head over to a friends this aft and burn a copy. Thanks for the suggestions.

Try those distortion tracks at Extremely low volume where you can barely hear them (or via a headphone). If the distortion happens only at a certain volume level or louder, it's the vibrations from your speakers/room that's getting in to your CDP's transport mechanism/servo.

BikeWNC · « **Reply #7 on:** 22 Mar 2004, 02:23 am »

On the new Norah Jones cd I definitely hear what I would call heavy ssss's. I took the disc to my car and still hear the same shussing of leading s sound. Same for my HT.

Andy

Scott F. · « **Reply #8 on:** 22 Mar 2004, 03:32 am »

Although rolling the tubes may help, I think it might be covering up another issue. Jitter.

Jitter is a notorious problem that can only be cured by a) a better player or b) a clock upgrade. I think Kevin at DIY offers a clock upgrade kit that is relatively inexpensive.

Another possibility is the your crossover in your speakers. Timing issues between the separate sections of the crossover can cause a nasty sibliance that mimmic exactly what you are talking about. Distorted S's, really hard sounding Ch's and a number of other audible anomolies that happen right at the crossover frequency.

The only cure for crossover distortions are the dreaded full range drivers.
Then the only cure for full range drivers are single ended triodes.
Jeeez, then it really goes downhill from there.

Rob Babcock · « **Reply #9 on:** 22 Mar 2004, 04:02 am »

I think DMason might disagree with you on the last part, Scott F. I might be wrong, but I think I recall him saying he was experimenting with driving full range single driver speakers with a little Tripath amp, with good results.

Sometimes sibilence is just a part of the recording, depending on how its miked...

markC · « **Reply #10 on:** 22 Mar 2004, 04:12 am »

Well, for whatever it's worth or whatever it means, here's what happened this aft. I took Nohra and Stacy over to my friends place to burn copies. Bear in mind that the burner is just that-a cdw. The Stacey Kent cd copied without a problem. However, the Nohra Jones disc took 3 attempts for the computer's cd player to read. After initiating the copy process, we went down to the "lab" where the work on the DIY dac is taking place. After a while we came upstairs to the computer to discover that the writer had rejected the copy process half way through and attempts to correct this failed. When I played the burned copy of Stacey Kent it supplied the same distorted results.

Scott F. · « **Reply #11 on:** 22 Mar 2004, 04:34 am »

You're right of course. No need to go off the deep end with SET's. In fact Martin King gave me a ration because he does his Lowthers with a 150 watt SS amp (or something like that). All of which is absolutely cool.

When I play the Norah Jones and Sarah M on my SET and FRers, I'm not getting any sibliance out of my rig. You are right though, I do have several recordings that do have it (sibliance).

Many of them are overproduced. They compress the digital recording, then ramp the sound up until it goes beyond the 0db mark and begins to clip, then they use a smoothing filter to further clip the sound (even though they think it is just rounding off the square wave they just created by all the previous nonsense).

The end result is a CD that is unlistenable. The latest that I've found like this is Robert Randolph and the Family Band's release Unclassified. Absolutely hideous processing. Great music, horrible mastering. Everybody in the studio involved with this POS should be slapped, really hard.

Another one that comes to mind is Karrin Allyson's Ballads. Great recording, minimal processing, really poor chioce in vocal mic's. Talking to Dennis are Pure Audiophile Records, they had to use a de-esser to remaster this on vinyl (you don't want to know how many S's they had to clip). You can really hear the Sss's on the CD. Pretty nasty actually.

Getting back to markC's issue. Don't underestimate jitter and crossover distortion. They are real and audible. Since his nOrh seems to be the constant in the situation, it sounds as if that could be the culperate. This is just a guess though.

The next logical step would be to borrow a better (or at least different) CD player and see if it still happens. Who knows though. It may well be the copy protection and my player is immune to it.

nathanm · « **Reply #12 on:** 22 Mar 2004, 06:11 pm »

It is most likely the recording and not so much your gear I'd wager. I think there is a spectrum analysis of a Diana Krall disc in the latest Stereophile mag wherein they showed some ugly hash in there, but I don't have the issue in front of me at the moment.

I think they like to goose the high treble on that kind of stuff because it increases the whole "I am being breathed on by a hot babe singer six inches from my face" intimacy thing with the vocal track. A hot mic\sibilant vocal does sound more in your face, but when it starts distorting things can get ugly.

markC · « **Reply #13 on:** 23 Mar 2004, 02:48 am »

Yeah, hot babe breathing on me from 6'' AWAY...BRINGS BACK MEMORIES... anyway back to my middle age life and audio. The thing that bothers me the most is that during the playback without the distortion happening, things sound very good. Vocals are exceptional on the Nora disc, (come away with me) very life like and dimentional within the room. The same can be said for Stacey Kent. And the same notes fry at the same point on the disc every time. And it's from the right tweeter. Oh well, I've still got Diana Krall, Holly Cole, Patricia Barber ,Steely Dan, Mark Knopfler, etc. All of these sound great and with no ssszzz.

ThePointBeing · « **Reply #14 on:** 26 Mar 2004, 03:53 am »

Assuming your equipment is of a certain quality, it is a lack of proper line condition that is causing the negative sibilance that you are hearing. With proper line conditioning you can remove all negative sibilance.

IMO

BikeWNC · « **Reply #15 on:** 27 Mar 2004, 01:35 am »

If your cables are on the floor, especially on carpet, it is possible that over time static charges will change the sonics of your system most often noticed in the high frequencies. If that is the case, power down your system completely, lift the cables off the floor and hear if things improve. I borrowed some clay flower pots from my wife to use as support for the cables.

Andy