Saturday, February 16th, 2019 01:33 pm
The OB-8 featured 8-voice polyphony, a VCF that was switchable between 2-pole and
4-pole, and the Oberheim "parallel buss" system which allowed it to interface with the
DMX drum machine and the DSX digital sequencer.
"Oberheim's OB Series instruments, including the OB-X, OB-Xa and OB-SX were, if not
the foundations, certainly the walls on which the company was built. This was
Oberheim's high spot, its heyday. And the OB-8 was the last of the series. OB synths all
have a certain warmth and richness, and although Tom Oberheim himself has gone on
record as saying he feels that the OB-8 is "too perfect" (well!) and lacks the grit of the
earlier models this is still a very human-sounding instrument. These synths were all
embraced by the R&B and dance merchants.
"The OB-8 has two VCOs per voice, each with sawtooth, pulse and triangle waveforms.
Oscillators can be tuned separately and then shackled together in hard sync for searing,
hollow lead line sounds. The OB-8 departs somewhat from the earlier OB designs in its
filter section, offering a choice of two-pole or the more drastic four-pole filter slopes. An
ADSR envelope generator is reserved for the filter. The filter is certainly precise, which
probably accounts for Tom Oberheim's slight retrospective misgivings on the
"LFO modulation can be in triangle, square, positive or negative ramp or sample-and-
hold waveshapes and can be used to modulate VCO frequency or pulse width, the VCF
cutoff frequency or the VCA. Deeper into the programming pages, you'll find additional
LFO functions for changing the LFO sweep to half-steps and "unsyncing" the LFO for
"The LFO can also effectively track the keyboard and thus speed up as you play higher
and higher. Portamento options of smooth or quantized travel and even polyphonic
portamento are also found here. Plenty of neat tricks and a taste of things to come,
when Oberheim went fully modulation-crazy on the Matrix-12 and the Xpander.
"Here on the OB-8, Oberheim (rightly) felt that such in-depth features could frighten off
the prospective programmer and so hid these advanced features in a "Page 2" mode.
This mode simply activates a second set of programming parameters under the control
of the regular panel knobs and switches once you double-press the Page 2/Chord
button. The nervous could then, and probably most often did, avoid the heavy
programming stuff and just get on with the playing. The Page 2 concept caught on to
such an extent that it somewhat rebounded on Oberheim, which subsequently had to
offer a new front-panel screen which signposted these secondary, hidden functions.
Oberheim charged $150 for this "upgrade," says synth guru and OB-8 owner Craig
Anderton, who decided to forgo the charge in favor of memorizing the commands. Now,
he says, not a little bemused, he has a more collectible unit because of it.
"The OB-8 came out on the cusp of MIDI -- just before it, in fact -- and so MIDI was
offered as a retrofit; it became standard from software revision D onwards. It was
obviously a bit of a rush job, since even the official MIDI version can only communicate
on channels 1-9, with just program, program dump and lever information being
transmitted (in addition to note data, of course). A ray of sunshine here is that in split
mode, two sounds will send out on separate channels.
"Patches come in either single or doubled/layered mode, with internal storage for 120 of
the former and 24 of the latter. A cassette interface was the original method of external
patch storage, though the MIDI iersion does allow patch data to be dumped and loaded
"The OB-8 represents a good blend of a player's and a programmer's instrument. The
flipper-type pitch and mod wheel isn't to everyone's liking, true, but the keyboard is firm
and the sounds feel playable. And there's a highly groovy arpeggiator that can be
clocked externally (via arpeggiator clock input jack, thus probably not directly via MIDI) if
"The OB-8 was the hub of Oberheim's "System," comprising the OB-8 keyboard, DMX
drum machine and DSX sequencer. It was quite the system to have for a brief period,
until MIDI arrived and blew the need for such restricted practices to smithereens. You
don't buy Oberheim synths for precision accuracy and reliability, but the OB-8 was by
far the most stable of the OB range and, when it did go out, the easiest to service."
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