Tempted by R2R?
I'f you are loaded, go the Otari (other pro deck), 15 IPS 2 Track, with a professional lined up to maintain it. The sound is far far better than any cable tweak, or batch of tweaks you could make.
For me and my 'well off' but not loaded crowd: Modest ProSumer deck to play 7-1/2" IPS, primarily pre-recorded tapes.
I went thru each era of Teacs:
1st. the early Stainless Steel face-plates with real wood end panels. Variations: Two 4 channel forward decks I restored and gave to musician friends. 2 Track to play my historic 2 Track Stereo Pre-Recorded Tapes from 1956-1958. After a while gave the deck to a musician and just gave the 2 track tapes to my friend with the pair of 2 Track Otari's.
btw, he can play the 'in-line' stereo tapes on his Otari, but not the 'staggared' stereo tapes (take a mono deck, add an adjacent head to make it 2 channel, now the left and right signals are physically separated by something like 1.25" distance between the heads/tracks. My Inherited Viking 2 track stereo deck (came in the Fisher President II I inherited from my uncle Johnny, along with the 2 track tapes) has an extra head, to select in-line or staggered. I have it downstairs with hard to find new belts waiting. Needs a new case, it was mounted in a drawer.
2nd. Next the beige plastic front panels, with plastic cases.
3rd. Finally the aluminum face plates, silver or mine anodized black. Plastic cases with optional 'wood look' surrounds (chip-board, wrapped with paper printed to look like wood). That is the end of the line X1000r and my X2000r's.
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I went thru: Single play, then reverse play, then 6 heads auto-reverse, start with that!
Many years back, I bought over 500 pre-recorded R2R tapes, 7"/7-1/2 IPS. Let's say the shipping cost more than the tape often, they were not expensive like today.
Mine have been stored in conditioned space, slightly slanted shelves: boxes edge to edge, and they still sound amazing, no bleed thru, strong signal strength, not stretching, bad edges. Except the 1st few feet each end, the tape is often brittle, a snap will break there, perhaps beat up edges. I add new polyester leaders to both ends, using a simple manual tape splicer. I add metal reverse strips, (the auto-reverse decks have sensors).
I sold about 150 of them, eBay, unconditional return/refund. Only 1 refund, seemed like USPS had a destructo challenge that day.
Many are over 60 years old, mine still sound better than my Vinyl, everyone here agrees.