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Old 31st December 2006, 09:33 PM   #11
john65b is offline john65b  United States
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I have restored four of these maggie MGAs in the past couple years. The biggest thing here is if your mylar is torn, don't even bother trying to fix them. A small tear is OK, but larger areas will not sound right at all. It will buzz like a buzzsaw.

First, read here...

http://www.integracoustics.com/MUG/MUG/tweaks/alex.html


I did not run a current through the wires to keep them down as I used a "new" adhesive. Read on...

Small tears need to be taped with scotch tape or similar. It is important to bring those two sections of mylar as close together as possible before you tape. as you do not want any slack in the mylar. I thought I could tighten the slack on one particularly large tear with a hair dryer...well it worked, till the mylar cooled down and then the slack returned...some here would shoot anyone with such an idea...I had little to lose (these MGAs were less than $100), but didn't quite work out.

The tweeter voice coil is usually corrodes away and requires replacement. Bass wires just come loose and need to be reglued. Wipe down the old crap glue with Acetone. The old glue will come right off, and the wires will lift off the mylar....

Now what I have done would most likely have a few here in an uproar, but has worked perfectly for me...I bought a small spool of Copper 36 gauge Magnet wire to replace the tweeter coil. This is not the original replacement aluminum, and the resistance (thus impedance) will be a bit slightly different, but it worked perfectly for me since I replaced both tweeter coils. Forget the scotchguard 77 Adhesive. Never worked for me, and leave a gunk that just weighs down the diaphrapm. I used (Ahem...) Weldwood from Home Depot as an adhesive. Worked like a charm. Run the wire thu a gob of it and lay the wires along the mylar. Use very little Weldwood, as this stuff is sticky as hell, and will weigh down the diaphragm if too much is applied...I went up and down the length of the speaker using a wodden peg jig. Using Welwood adhesive, these wires will never come loose again. I used it on the bass wires too. The last thing I did was a thin brush coating of the blue stuff from magnepan (Milloxane) You need to order this from magnean and it is cheap. Milloxane is not really just for gluing, but it also will filter out UV rays which will harm the mylar... Magnepan will not send out Milloxane in the winter due to its ability to set up and not return to a liquid phase.

All in all it took the better part of a weekend to restore a pair of SMGAs, and the learning curve is not so bad.... They all sounded excellent!

I sold all four pairs and made enough money to buy a pair of MMGs and build a few gainclone amps. The MMGs have an aluminum ribbon instead of wire, and are much more diffcult to repair, but I have yet to hear anyone saying their coils have come loose on their MMG's - they use a much better glue these days... I like the MMGs a little more than the SMGAs, they sound more focused and clear...and are a bit smaller too...


Just my 2 cents boys and squirrels, again YMMV...
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Old 31st December 2006, 10:50 PM   #12
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From my experience with 3M 77 (art projects with the kids, etc.) I don't think it would be appropriate for Magneplanar repair.
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Old 31st December 2006, 11:45 PM   #13
john65b is offline john65b  United States
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Believe it or not, it is whart Magnepan was recommending a few years back for the repair of wired voice coils...
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Old 3rd January 2007, 03:32 AM   #14
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I am making the call to Magnepan tomorrow!
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Old 9th January 2007, 12:49 AM   #15
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hey, I got everything from Magnapan exept for the Water-based glue, is there any way I can do without it? I bought alot of both weldwood, and super 77 (in case I needed it). its too cold out to ship the water-based glue, and I haven't found a hardware store that carries the generic 3M 30NF, i'll keep looking.

I did all of the acetone stuff today pretty strong stuff, the only problem is that the only place for the speakers to sit while the fumes die down is the gargage, which is a burning 30 degrees (farenheit) right now.

will I be okay with just the Weldwood? or it with the super 77? or do I need to wait 6 %$%^*(*&(*&(&^%R^# months before I can use my new speakers!

-Moose
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Old 9th January 2007, 04:47 PM   #16
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Google is your friend - for example,

http://www.1stchoiceindustrial.com/d...medium=froogle

or try yellow pages for a contractor tool / supply store near you.
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Old 9th January 2007, 07:20 PM   #17
john65b is offline john65b  United States
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I would pass on the 3M 77, but definitely use the Milloxane. It blocks harmfull UV.

Now I think you can get away with coating the Milloxane later in a few months when they start delivering it again...
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Old 10th January 2007, 02:03 AM   #18
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I just repaired a pair of SMGa speakers using regular contact cement - the type that comes in a metal can with a brush attached to the lid. I tried this and Weldwood in an experiment before atacking the speakers (very similar).

Beware to get a good fresh bottle of Weldwood. The first bottle I bought had separated and was useless - it had clearly "gone off" and would not apply or work properly.

The method is similar to that described by others on the Maggie User Group website (Audio assylum...) and seems to be foolproof. The only unpleasent part is stripping the old adhesive with solvent. Luckily, only the bass wires needed any attention on my speakers, the treble sections were undamaged.

Ed
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Old 10th January 2007, 02:15 AM   #19
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I did the first tweeter with weldwood today, its drying right now, but it seems to hold extreemly well, I am excited to get these up and running
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Old 10th January 2007, 03:45 AM   #20
john65b is offline john65b  United States
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Yes, fresh weldwood is key. I glued some wood parts together a few months back with an old can of weldwood and it still has not dried and held...

Use just enough weldwood to keep the wire onto the mylar. You don't really want to have globs of goo, but I would sweat it too much if you already have some here and there..
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