What am I hearing???


~~~~Hello,
I hope someone can explain why on some cd's the long piano notes sound slightly warbled. Not the normal vibration from the piano's wires. Am I hearing laser trying to track info on a non-concentric disc? I noticed a lot of cd's data area slightly non-concentric to edge of disc. Shouldn't the laser be able to trace imperfections? Warranty time? Starting to bug me, RATS!

Just The Facts
By
fbi
Good explanation Stehno.

One reason for time smearing in cables (or any device passing an electrical signal) is the dielectric effect of the insulation layer. Since no insulation except a vacuum is perfect, some of the signal will travel through the insulation instead of through the wire itself. The propagation speed of the signal through different materials is different, so by the time it gets to the other end of the cable the effects can be audible. It is easily audible if you compare, for example, zip cord to a decent speaker cable.

Mechanical time smearing often occurs in LP playback. TT designers go to great lengths (or should do anyway) to make sure their decks run at perfectly stable speed. Any deviation is audible in instrumental timbres long before it gets to the point of pitch-wavering.

Fbi - you say this problem is only on SOME CD's. Any chance you're hearing tape stretch or tape deck motor irregularities from original analog recordings of less than stellar quality? Try the suspect CD's on another player before assuming there's something wrong with yours.
Stehno wrote:
"In essence, a poorly designed cable will produce or generate the exact same (moment in time) musical signal muliple times before the signal completes it's travels to the other end of the cable."

Not quite. Smearing in cables has to do with the dielectric absorption. It is simply charge stored in the cable dielectric that releases more slowly than air would.

Now, transmission-line reflections will cause a digital signal edge to reflect back and forth between the source and destination multiple times if the cable is low-loss.

I would suspect that an audible warble from a CDP is probably bad jitter or WOW from the transport mechanism. The servo is not keeping pace with the rotation.
The most probable explanation is that you are listening to CDs originally recorded to analogue tape, and what you're hearing is the speed variation of that tape.

Things it is definitely not:
--non-concentric CDs
--laser problems
--"time-smearing" of cables
--transport "wow"

None of those things can cause the effect you are hearing.
I have what i believe is a similar problem...i notice it only on piano music, it sounds like the tweater of my left speaker is distorting, simmilar in sound to when a speaker clips, only not nearly as loud, but audible from my listening location...it also seems to be frequency dependent..ie. only occures, or occures to a much great level within a certain frequency range.

when i first noticed the problem i returned the speaker and they replaced the tweeter with a new one, but the problem persists...

my system is

totem arros
nad c350
kimber 8pr cable
eichmann express 4 interconnect
dennon dcd 3520 cd player

any idea what it could be...I wouldn't think two tweeters could both exhibit the same problem unless its a design flaw with that model of speaker (unlikely)... i thought mabey the piano notes happened to fall right around the crossover point of the speakers and that somehow caused the distortion...

any ideas...
Following the logic of using your headphones to isolate the problem,use a cd player you know is good and substitute it for your cd player to see if it your source or not.