If rca, did you connect the return lead of the meter directly to the ground sleeve of the rca jack being measured, or to some other presumed ground point, such as chassis?
This was the problem. When I took my measurements yesterday, I connected the return lead to the chassis. When I took the measurements again today, this time with the return lead connected directly to the ground sleeve of the rca jack, the measurements were well within the noise floor of the meter, i.e., fluctuating between 0ACV and .2ACV for both the preamp's output and the amp's input. Thank you, Al, not only for being smart, but also for being able to think like a dummy like me. I will now never forget the phrase "presumed ground point."
It is worth noting that the problems with the Meridian seem to appear when it is powered up for several days at a time. In light of that, I think I will leave it on for a day or two, and then retake the measurements at its outputs.
As far as the diagnosis of the problem, it is appearing less and less likely that my Meridian dealer is correct in his theory that the Pass amp is the cause of the problem, which is consistent with the doubts expressed by many people here. Another relevant observation: I am unaware of Pass customers experiencing reliability problems with the XA30.5, but I know of several Meridian customers experiencing reliability problems with the G68, including several folks whose G68 power supplies have failed. That is circumstantial evidence, but suggestive of the locus of the problem.
I have decided not to return the G68 to Meridian America after all. I am not confident that they can fix the problem, and I do not want to spend thousands of additional dollars for them to attempt a fix (the first repair attempt was $800). Even my Meridian dealer warns that spending more money to try to fix this problem in the G68 might be, to use his words, throwing good money after bad.
So here is MY PRESENT DILEMMA: I would like to simply leave the G68 in the system and get all the remaining life out of it, especially in light of the fact that I just spent $800 on a repair and $1200 on mods to the unit. Then when it fails, in six months or a year, I can rebuild the system with components from other manufacturers. However, my fear is that, by leaving the G68 in the system, I will be risking damage to other components. That fear is based on the recent damage to my center channel.
To decide on the best way to proceed, I need to figure out whether the G68 caused the damage to the center channel, or whether the failure of the center channel is a coincidence. Could the loud "pops" that occasionally make their way to the speakers have damaged the center channel? Or could the G68 have damaged it in some other way?
Anyone have any thoughts about these last questions?
