Echolplex problems

[Chris Chovit <cho@gomez.jpl.nasa.gov>]

Hello all,

Well, I think its about time to bring up some of the problems I've been
having with the Oberheim echolplex.  I'd like to make sure that I'm not
alone, and maybe someone can suggest some solutions.  There are two main
problems I've run across, one of which has been solved, but I'll mention it
anyways, in case someone else is experiencing the same thing:

1.  The brother sync (which allows multiple echoplexes to be synced
together, and also allows any of the linked units to be the "master") does
not work with more than three units, although the manual would lead you to
believe that it does.  When I tried to sync my two units with my brother's
(he's really my brother!) two units, I experienced some weirdness:  None of
the units would receive the sync pulse from any of the other units.  After
successfuly syncing every combination of "three unit" setups, and checking
my cables, I determined that the individual units were operating OK -- but
when 4 units were "brother synced" together, the sync would not work
properly.  After bringing this to Kim's attention, he discovered a design
flaw:  it turns out this problem can be solved with a simple resistor swap.
(Kim, perhaps you can restate the details of this for others who may be
attempting to sync 4 or more units together).

2.  I have tried to sync my echoplex to a MIDI sequencer, by programming
the sequencer to send out the two record pulses (which define the loop
length) via MIDI NOTE ON messages.  However, after a few minutes, the
echolplex loop begins to "drift" away from the sequencer.  How can I solve
this problem?  Is there a way to keep the echoplex synced to the sequencer
indefinetly.

(I have successfully gotten past this by syncing the sequencer off the
echoplex, but this does not suit my purposes as well).

3.  I guess I should mention another minor bug, when using the brother
sync:  Often the echolplexes do not Power ON correctly, when connected to
other units via the brother sync.  In this case, I need to unplug all the
brother sync cables, power on the units, then plug the brother sync cables
back in.

4.  I guess I would also like to take this opportunity to perform a little
"Oberheim bashing":  While the echoplex units are quite remarkable, and
bugs are to be expected from such new technology, I am quite unsatisfied
with Oberheim's customer service.  They do not answer their phones.  Many
times they have not returned my calls.  They have denied that these bugs
exist.  My brother and I sent in our units months ago, to be upgraded, and
we haven't heard one word from them regarding their status -- they won't
return our calls!  (for all I know, $2000 worth of out equipment was lost
in the mail!).  Anyways, enough about that.  My goal isn't really to bash
Oberheim -- but I want to make my experiences known.

By the way, this last item does not apply to my dealings with Kim.  He has
been quite helpful, and I really appreciate his service!

Keep on loopin'!

- Chris


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Chris Chovit
cho@gomez.jpl.nasa.gov
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