This is an article culled from archive material, circa 1997.

The DPM SP was the first sampler which addressed all of my criticisms
with previous products. It was also one of the first batch of
Peavey's
products aimed at the professional synth/keyboard market.
The SP is expandable with standard SIMMs (up to
32MB), can drive conventional cheap SCSI hard disks, and allows
external graphical wave editing via SCSI transfer. And it was cheaper
than comparable models at the time of launch.
The voice architecture is respectable (16 voices into two stereo
outputs, with dynamic voice allocation, voice reserve and exclusion),
let down only by weak filtering (lowpass only, no resonance). The MIDI
implementation is decent, although system exclusive transfer and
editing only arrived with version 1.4 of the operating system. The file
system in particular is nicely designed, with the ability to load voice
components from other banks, with checksumming used to avoid duplication.
Samples can be transferred using
SMDI (SCSI MIDI Data Exchange), a
"standard" for encapsulating MIDI over SCSI which only
Kurzweil
has chosen to implement as well, on its K2000
series. I used a DPM SP for about a year, editing samples over SCSI with
Passport Designs'
Alchemy on an
Apple PowerBook 170, and found it easy and convenient.
The DPM SX is a dedicated sampling front-end for the DPM SP (which
cannot sample by itself). Since the SX supports SMDI and
MIDI Sample Dump Standard, it is conceivably of use to
owners of other sample-based instruments.
The SX has its own sample RAM, with a maximum of (I believe) 16MB.
However, it only samples in mono; the later
SX II will
sample in stereo,
and will even sample directly into a SP's RAM using SCSI.
There has been talk for at least a year of an
SP Plus sampler with
improved features, including resonant filters. I have not seen one
yet.