We're talking 'bout secondhand consumer gear here.

S/N ratio only starts to count if you recap and recalibrate. Something the OP might not do...

Personally, I don't like Sony gear. Too many parts that are no longer available. Some parts that weren't available on the open market even when the stuff was new. I've worked for Sony pro service.

 

I disagree. S/N ratio starts as soon as you acquired a specific cassette tape. You are stuck with theS/N ratio specs of the device. The higher, the better. This all translate to better sound quality.

 

@FrankWhite23 Another fact for you to consider prior t making a decision is that not all cassette tapes are made equally. Some heads are not "compatible" with metal tapes, specially when it comes time to recording. Playback should not a problem if the deck can handle 70uS eq. Therefore, you must be careful. Also a 90 minutes tape is thinner than a 60 minutes tape. Theoretically, there is a 3-4db difference in noise level favoring the wider tape.