While 32/16 may have worked...the source was likely 32/12
http://www.solorb.com/dat-heads/digests/V6.200/D295#Msg1{19} What's the rundown on Long Play mode?
Long-play tapes are recorded at 32kHz, but there are two 32kHz
standards.
The 32 kHz Long Play standard uses a non-linear 12-bit quantization
scheme. That's how they get 92 dB or whatever out of 12 bits - the
buckets at the quiet end of the spectrum are bigger. This means that
you'll theoretically get more distortion at low recording levels than
you would ordinarily. That and the fact that frequency response is
limited to 16 kHz are the trade-offs you make to get twice the time for
your hard-earned DAT dollar. This is because you are storing less data
per second of sound, so you get 240 minutes out of a 120 minute tape.
The other 32kHz standard is a 16-bit one that is (apparently) only used
by the broadcast industry. You get no tape savings as a trade-off of
losing half an octave of music. This is the 32kHz standard supported by
the Panasonic SV-3700 - however, you can only record in 32kHz 16-bit
mode through the AES/EBU digital interface. So unless you have digital
broadcast equipment with an AES/EBU port, you won't have much use for
this mode.