Need info on MIDIVERB2 power adaptor..

[David Lee]

Thanks to all for the help.... I looked at a used one during lunch at
GuitarCenter in Dallas. It is infact an AC adaptor at 9v. As it turns out
the MMT8 and the Midiverb use the same AC adaptors (...info from an alesis
tech support email that took 3 days in response). Lucky for me I have an
old MMT8 in the closet that is doing nothing with a perfectly good AC power
supply.

As a backup I am going to order another adaptor from Alesis just to insure
that I get the proper model.
:)

Thanks Gents

David Lee

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From: KA4HJH <terrymbowman at rica.net>
To: synth-diy at mailhost.bpa.nl
Subject: Re: Need info on MIDIVERB2 power adaptor..
Date: Wednesday, June 24, 1998 3:38 PM

>My MIDIVERB2 has gone south on me do to a failed factory 9v power supply.
I
>was hoping someone has one of these units and could tell me the following:
>
>1. Is the + power lead on the tip or the ring of the 2.1mm power
connector?
>2. What is the stock transformers current rating in mA?

You may be able to repair the existing power supply, assuming that it's bad
and not the MIDIVERB2.

First, check the wire and plug very carefully for nicks, pinches, hard
bends, or any other sign of mechanical strain. Even if this is a fairly new
unit it could have gotten damaged somewhere along the way. (This has
happened to me more than once.)

If the wiring looks suspicious, try splicing around it. If the wire is
damaged in the strain relief, you'll have to install a new plug, which is a
problem if you don't know the polarity. If you dare open the MIDIVERB2 you
can probably determine very quickly what the polarity is. Hint: check and
record the polarity of every new gadget you buy while it's still working!
These things have a way of going bad. Make sure the replacement is the
exact same size (I'm thinking of "barrel" connectors here) or you might
cause another problem.

If you get this far without a smoking gun it's probably (probably) an
internal problem. You'll have to crack it open. I use an X-acto razor saw,
the one with something like 64+ teeth per inch. It only takes a few minutes
of judicious sawing to get enough openings to lever it open the rest of the
way with a couple of small screwdrivers. You'd be amazed how easily most of
them pop open (with some loud cracks). Each one is glued together in a
different way so take your time and study it as you go along. Eventually it
will yield.

Now you have a simple power supply to troubleshoot. One of the most common
failures in these things is one of the tiny (very small gauge) secondary
wires breaking off a solder joint. One good drop probably did it. Whatever
the problem, be carefully while handling the guts so you don't accidently
break one of them in the process of fixing the thing.

If you are careful and lucky, you might be able to glue the whole thing
back together once everything is working again without it looking too
chewed up.

Remember, make sure it's not an outside problem before you start sawing.
Otherwise, you really don't have much too lose at this point.

Good luck.

Terry Bowman, KA4HJH
"The Mac Doctor"