The Marantz CD-50 is basically the same machine. The circles (your 'blobs') and their associated wire links are shown on the circuit board on page 17 of the service manual, which should reveal their purpose.
I found the circles on the page of the SM, saw that they are listed under mechanical parts, saw on the schematic that some traces terminate under the circle, but cannot find that symbol's description. Googling the part number did not reveal anything. I'm ready for my next clue!
I appreciate the help, but I'm getting lost.
1. Is the ground plane on both sides of the board?
2. If the back side of my board has 3 components, one of which is a SAA7310GP, does it qualify as a double-sided or stacked board?
3. Do need to drill a hole through the blobs and solder the ends of a wire to each side of the board?
No, the ground plane is only on one side (the one with the blobs).
Double-sided just means it has copper on two sides; the location of components is another matter.
There are traces on the other side of the board under the blobs. Drill through them and you'll short those traces out.
@poynton I know you had recommended the "griplet mod" in previous threads, but looking back, it seems all of those threads concerned the CD 104, so it may be I can quit worring about them!
@Galu Originally, the 650Hz wobble frequency was so loud I could hear it over the music (I sit close to the machine). I took it apart to replace some caps, and now it won't recognize a disc. I'm not throwing in the towel yet, however.