I received a query from a gentleman in Europe about 1.875 in/s 4-track tapes. He was frustrated in finding a good machine for transferring them. Apparently, they have many of these tapes. Here are my suggestions.
Perhaps the easiest answer is to find a Studer-Revox C274 with low speed options. They were made.
Two other options.
(1) the Sony APR-5000 will go to 1.88 in/s by using its -50% varispeed. Most of the ones I’ve had do an adequate job at that speed, but I’ve been cautioned by the ex-Sony guys on my Sony APR mailing list that this is way outside of design spec. I use Nortronics in-line 4-track heads, but I’m also in the middle of building a staggered 1/3, 2/4 head assembly since that will improve inter-program crosstalk. None of these heads do really well due to gap length considerations. I suspect (I haven’t done the math) that you want a 50 micro-inch or shorter gap to do this well.
(2) The Racal Store 4DS instrumentation recorder which has constant-flux playback equalization (needs to be filtered in the computer afterward) and is not fantastic for S/N ratio actually goes to 15/16 in/s and is a 4-track machine. The previous two entries here feature this interesting machine. I did invest in three of them (the one in the pictures is the prettiest) as well as a 1/2-inch 7-track 7DS.
Someday, I might get a C274 logger…but I prefer adapting versatile transports to specific applications rather than collecting dedicated-per-format machines.