I discovered the excellent sound of pre-recorded reel to reel tapes in 2012 and now thanks to Ebay I have an extensive library of tapes. (see this website – reel to reel)
I use a Technics RS1500. The playback heads are wired with Mogami cable and exit the machine to feed a CYMER tape head preamplifier. I asked Elson Silva of CYMER to make me a preamp (without line stage) and he did. It’s based on the Marantz 7c and sounds magnificent. It uses two 12AX7 and a 12AT7 per channel; the power supply is outboard. It is dual mono. I use the tubes I recommend for the Doge 8 (see that section).
I have used the Bottlehead kit which sounded pretty bad. So bad in fact that I sent it back for a check up. Bottlehead said it sounded great. Here it was rolled off in the highs, muddy in the mids and woefully noisy.
As a stop gap I used a Shure M64E, surprisingly good considering what it is and how old it is.
There is a real scarcity of preamps for tape heads, so I urge you to invest in Elson’s. It is not expensive either ($AU1200). Contact him on firstname.lastname@example.org
I have no financial affiliation with Elson.