I tried some things last night.
I checked the tone arm cable connection. The connectors good. I cleaned up the RCA ends on the cable. The cable is in good shape, but it seems like some cheap thing you would get at Radio Shack for $5.
I cleaned the inputs on the Sansui. I used electrical contact cleaner and a Q-tip.
I plugged into Phono 2. It did not seem any different from phono 1, but I did notice there is a tiny cross talk between the two phono inputs.
I removed the stylus, took some pictures, cleaned it, put it back on. I also checked the movement of the stylus with a toothpick. The stylus seems to move fine, it has maybe a 2 or 3mm range of motion.
I hooked everything up to a different receiver.
I grounded the deck, arm was already grounded.
I played four different albums. While playing these, I also played the same song through my phone on the aux input, so I could switch back and fourth between them and have a reference for the sound of each song.
The first whole album, Acid Bath's "Paegan Terrorism Tactics" (new pressing, has been played maybe once), sounded like garbage. Highs were harsh, mids sounded like they were running through a distortion pedal and the drums and bass guitar were there but they were quiet and had not punch, attack or drive. They were very muffled compared to the streaming mp3 and there was so little definition in the drums, you couldn't make out the individual beats.
Next I played The Police. I think it is a greatest hits album (Dollar bin used album). "Roxanne" is the first song, and it sounded just the same as the previous album. The next song though, message in a bottle actually sounded fairly decent. The highs were less harsh, the mids were clear, and the low kick drum was there, but there was still nothing in the lower midrange or upper low end.
Next I played Sufjan Stevens "Common Feel The Illinois!" (New pressing clean and in great shape). It actually sounded pretty decent. Switching back and forth between sources, I could tell that the record had better highs and mids and was smoother overall with a greater range (obviously). But it still lacked that low end that I am getting from other sources. Overall the Music just didn't have much presence, punch or drive to it and didn't sound like it was all there. (Describing sound is hard!).
Lastly I played My Life With The Thrill Kill Cult's "Confessions of a Knife". Sounded the same as the previous album.
So I guess overall it actually sounds a little bit better, not quite as harsh or fatiguing, but still bad. I had a friend over as well and on all occasions he felt that the Mp3 sounded better without me telling him which source was which.
