Strange Oscillation

falconquest,
all good suggestions by other A'gon members. Here's another thing to try - use a black Sharpie to paint the outer rim of the CD (similar concept to using a Stoplight pen). I've done this to some of my favourite music CDs. Since the black line (the width of the Sharpie nib) is along the outer rim where there is no music/data content it will not affect reading the disk. What this black ring on the outer rim does is reduce/eliminate any laser reflection & multiple erroneous pick-up of data during read-back which is one source of distortion.
if it does nothing for you, you can use alcohol & erase this black ring & your CD will be back to its original looks.
Many of my CDs which have a transparent section at the center spindle hole have been colored black using a Sharpie in addition to a black outer ring. It might not make any difference but it helps cut down on laser reflection off the shiny disk. FWIW. YMMV.  

Yes, as Bombaywalla indicated a number of good suggestions have been made. And as the diversity of those suggestions shows, there are a lot of different possibilities that may account for the issue. Some further thoughts:

First, just to be sure, is the MFSL DSOTM truly just a redbook CD, or might it have an SACD layer as well, that may be what has been played without the issue appearing?

Second, given that the problem is both volume sensitive and note sensitive, the only effects I can envision that might be occurring are:

1)The player’s ability to track and/or read the disc is marginal, and vibration may be putting it over the edge when the problematic notes are played at high volume. (I would not assume that the two versions of DSOTM, one of which precipitates the problem and one of which does not, have been mastered identically). Good suggestions have been made above regarding this possibility.

2)Either the power amp or the circuitry in the preamp that is downstream of the volume control may be marginally stable, and certain notes may be putting it over the edge. (Again, I would not assume that the two versions of DSOTM, one of which precipitates the problem and one of which does not, have been mastered identically).

3)The amount of current drawn by the power amp when the problematic notes occur may be affecting the AC line voltage, and that fluctuation in line voltage may be affecting something that is marginal in the system.

Regarding nos. 2 and 3, if I’m not mistaken your power amp can be switched between class A and class AB operation. As an experiment, it may be worth trying it in whichever of those modes you have not been using.

Also, as an experiment it may be worth trying the listen/measure switch that is on the back of the Ayre CDP in whichever position you have not been using.

And it would certainly make sense to try the problematic CDs in the Oppo player you appear to have in your system.

Regarding Williewonka’s suggestion of trying different speaker cables, I agree that the application of excessive load capacitance to the power amp outputs could conceivably be involved. Especially given that your speakers have highly capacitive phase angles at certain frequencies, as well as low impedance. Although it appears from your system description photos that the cable lengths you are using are probably fairly short, which means that the unspecified capacitance of your Morrow cables is probably not especially high. In any event, as an experiment you could reduce the capacitance the cables present to the amp by a factor of two by disconnecting one of the two biwire runs, insulating the disconnected exposed terminations, and using jumpers on the speaker terminals.

Just some thoughts. Regards,
-- Al

falconquest,
an addition to my orig post keeping in mind Almarg's point #1 - if you can get a hold of a CD mat that experiment might also be useful. CD mats are often used to dampen vibration, squelch laser reflections & generally aid in producing clearer, more defined digital playback without overburdening the motor spinning the CD. I think this would be an additional good experiment, if feasible. Thanks.

P.S. to my previous post: My suggestion about cutting the speaker cable capacitance in half (as seen by the amp) assumes that one of the two biwire runs can be disconnected at BOTH ends, while leaving the other run in place and jumpering the high and low frequency speaker terminals. Disconnecting one of the runs at just one end, such as at the speaker terminals, will not result in a significant change to the cable capacitance that is seen by the amp.

Regards,
-- Al
 

It's not the player guys.  Such oscillations are downstream in the preamp or amp.