Roland Space Echo

[Haible Juergen]

	>what is so special about this unit?
	>
	>It is said to be a sound miracle, if it works.

Yes, it is something special. I will never part with mine.
Possible reasons ? I'll give it a try:

(1) Just the right amount of speed variance to create a very subtle
chorusing effect when the delayed signal is mixed with the original.
The "wow and flutter" you often get on cheap cassete decks when they 
grow old. Not much affair on pop music, but annoying for solo piano
parts - you know what I mean. Just the right amount for that chorus
on delay effect. Not *more* wow and flutter, please. I can imagine 
that a broken Space Echo will produce a higher amount of speed
variation - the one that was used by Line 6 to model the DL-4
probably was one of that kind 8-( -, which *might* be interesting
on its own, but the "outer space" sound that fits the name of these devices,
the "magic", is achieved with the sublte, *slight* chorusing of a
good Space Echo, not a broken one.

(2) Tape saturation.
Tape saturation is a very different physical process than limiting
voltages, even when the signals are equalized before the limiting.
It's a pleasant sound - I wouldn't like to miss that.

(3) The electronics
Now, every tape does saturate, but I guess the circuits that drive
the magnetic head and that amplify the returned signal make
a difference, too. For the tape saturation to appear in full beauty,
you'd expect the electronic circuits to limit the signal much 
*later* (at higher levels) than the tape. In other words, lots
of headroom. Disclaimer: I have not measured the headroom,
so this is more guessing than knowing - I'm trying to interpret
what I hear.
Now, *when* the electronics finally do some clipping, that's no
opamps getting stuck at power supply rails, as in many other
delays. The Space Echo is built from discreet transistors, in
class A circuits.

(4) And don't forget the loss in the treble range with each
repetition. (That's easy to emulate of course.)

Martin, as I know that you have a copy of my CD, let me refer to
two titles that might demonstrate the Space Echo Sound:
"A Sultry Night" (Track 11) makes use of the Space Echo's 
chorusing delay, and "Facing The Shadow" (Track 12) has a lot
of Space Echo tape saturation on the organ. (There are other
means of distortion on that track as well, but the smoother
parts are from the Space Echo.)

JH.


> m.c.
> 
> :::User-Agent: Microsoft-Outlook-Express-Macintosh-Edition/5.02.2022
> :::Date: Thu, 08 Jun 2000 09:20:15 -0700
> :::Subject: Roland Space Echo
> :::From: Nick Thompson <rextanka at earthlink.net>
> :::To: Synth-DIY <synth-diy at node12b53.a2000.nl>
> :::Content-transfer-encoding: 7bit
> :::
> :::Hi,
> :::
> :::I hope this is not too off topic.  I have a Roland space echo that is
> not
> :::functional.  Mechanically it seems fine (the tape moves across the
> heads,
> :::the speed control slows and speeds it up).  The reverb part is fine
> too.
> :::The problem here is that sound just builds up into a cacophonous wail.
> :::
> :::I really want to get it working again, is there anyone here here who
> can
> :::work on it and diagnose and fix it?  I tried my local (and usually
> really
> :::great) tech, at musicians service center in San Jose, and he diagnosed
> a bad
> :::erase head.  He said Roland were out of parts, so he would not be able
> to
> :::work on it.  This guy is a usually a great tech - he's bought many an
> old
> :::piece of junk back to life.
> :::
> :::So what I'm looking for is a tech somewhere who has some experience
> working
> :::with tape delays, to attempt to diagnose the problem and (hopefully)
> fix it.
> :::I know there are several service people on the list, and there maybe a
> DIY
> :::person who knows a lot about these.
> :::
> :::If you can email me that would be wonderful.  I don't really want to do
> this
> :::as a diy project myself because I'd really like to have a good chance
> of
> :::making this work again :)  And I can just about do solid state
> electronics,
> :::all of the mechanical elements of this are probably beyond me, as are
> tape
> :::machines.
> :::
> :::Many thanks!!
> :::
> :::Nick