The Tascam MS-16 was made as a single-speed machine, 15 or 30ips but not both.
Interestingly, the capstan servo can run (by changing jumpers) at 7.5, 15, or 30 ips. I have modified my machine with a DP3T switch on the outside to do this, for varispeed FX.
However, the audio cards do not...