I have a Technics RS 1500 that I modified by replacing all the electrolytic capacitors with "Black Gates", and also replacing all the transistors with new ones. Panasonic people are wonderful to do business with; while I didn't get the caps from them, they supplied the new transistors, plus new tape rollers.
As you know, the noise floor is related to the signal level, and that's where you would hear tape hiss. If the signal level is automatically higher than the noise floor, tape hiss will not be heard.
What I'm saying, is that if my music signal is strong at a low level, it will so over ride the noise floor as not to be heard. In the past, when I had that cheap AKAI, I definitely remember tape hiss. I don't know if you know about "Black Gate" capacitors, but they are definitely a game changer, and will command a higher price and a quick sale for any working component that has them.
When I was listening to playback of a brand new record, just a few minutes ago, I heard record noise, that constant low level noise during silence, but no tape hiss; I've been doing this long enough to know the difference.