After the bigga DT-2001 (1988) based on the Alpine mechanism used by all Teac and Tascam DAT recorders, Onkyo made another effort at DAT with a... rebadged Technics SV-DA10. Cheaper but therefore sporting the ultra-reliable RAA1001 mechanism.
Being from 1990 (like the DTC-55ES), the DT-9000 has SCMS.
The rest, bar the jog/shuttle function of the original, is an SV-DA10, FL display included - but it does have two independent 1bit a/d ICs.
The audio stages were however developed by Onkyo and not straight imports from the Technics SV-3700 / SV-3900 / SV-4100 / SV-DA10 / SV-D900 series.
The later DT-901 also was Technics-based : Onkyo remained an "extra" regarding DAT and never developed anything on its own.