Lewm,
"I cannot imagine how "knocking" the cartridge out of alignment could produce the phenomenon that you described."
It can easily do that. The groove in a record is shaped like a V. The info for the right and left channels are on each side of the wall. If the cart is not aligned properly, it may not be fully able to touch both walls the amount it needs to produce full resolution, causing an intermittent problem. I also said "or something similar". Things like not having enough tracking force, anti skating and SRA, can also contribute as well. If the problem is alignment related, it can very well be a combination of the above. Or, like you say, it may be something else entirely.
As far as your CD player goes, that seems like an interesting problem, as well. I think you need to find out what is different about Bill Thalmann's workbench than your equipment rack. (I know that sounds like a smart ass remark, but its not.) There really may be some difference you are not aware of that is causing the problem. It could even be temperature related. Just by taking it out of your system for a while may let it cool long enough for to work.
"I cannot imagine how "knocking" the cartridge out of alignment could produce the phenomenon that you described."
It can easily do that. The groove in a record is shaped like a V. The info for the right and left channels are on each side of the wall. If the cart is not aligned properly, it may not be fully able to touch both walls the amount it needs to produce full resolution, causing an intermittent problem. I also said "or something similar". Things like not having enough tracking force, anti skating and SRA, can also contribute as well. If the problem is alignment related, it can very well be a combination of the above. Or, like you say, it may be something else entirely.
As far as your CD player goes, that seems like an interesting problem, as well. I think you need to find out what is different about Bill Thalmann's workbench than your equipment rack. (I know that sounds like a smart ass remark, but its not.) There really may be some difference you are not aware of that is causing the problem. It could even be temperature related. Just by taking it out of your system for a while may let it cool long enough for to work.