Painting Yamaha NS-690 Speaker Aluminum Faceplates

Sasquatch2

Active Member
I'm restoring a pair of NS-690's. I have the pulled the screens off the mids to restore the soft domes to their original shape(screens pushed in) and noticed some mild powdering on the metal finish. Looks like the original finish was pretty thin. I am thinking about cleaning them off with some Isopropyl alcohol and then refinishing with some new silver paint. Has anyone tried this? Thanks in advance for any input.
 
Same issue with my NS-1000M drivers. I am planing to lightly sand the gray surface and use automotive matching paint to restore it. I do not see any issue with that, if you properly mask the guts of the speaker to avoid any over-spray.
I would have left mine alone if it was just the peeling, but my screens are also pushed in.

Good Luck!
 
I'm restoring a pair of NS-690's. I have the pulled the screens off the mids to restore the soft domes to their original shape(screens pushed in) and noticed some mild powdering on the metal finish. Looks like the original finish was pretty thin. I am thinking about cleaning them off with some Isopropyl alcohol and then refinishing with some new silver paint. Has anyone tried this? Thanks in advance for any input.

Probably look fine. I acquired a pair of 690 tweets a while back. That were oxidized like yours.I just bead blasted the aluminum frames.Then gave them a clear coat of urethane.
 
Probably look fine. I acquired a pair of 690 tweets a while back. That were oxidized like yours.I just bead blasted the aluminum frames.Then gave them a clear coat of urethane.

That is actually the way to go it you have access to a bead blaster.
 
I'm restoring a pair of NS-690's. I have the pulled the screens off the mids to restore the soft domes to their original shape(screens pushed in) and noticed some mild powdering on the metal finish. Looks like the original finish was pretty thin. I am thinking about cleaning them off with some Isopropyl alcohol and then refinishing with some new silver paint. Has anyone tried this? Thanks in advance for any input.

How did you reform the domes? I can't get the dimpling totally gone even with gentle suction on the entire driver

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I fabricated a piece of foam similar to the contour of the dome and inserted it through the back of the magnet to push it back into shape. I let the dome warm up in the sun for a bit to soften it before using the foam. After inserting the foam, I let it sit out for quite a while in the sun and eventually it came back. Allow the unit to cool down to room temp overnight before removing the foam. As you insert the foam you will notice that the dome will move slightly outward so you have to be careful not to apply too much pressure as not the voice coil is moving too. I've done 5 now and the last one was a bit of a toughie so I tried a hair dryer on it to tweak it.....too much heat might ruin everything. It worked fine but caution again on the heat. I also made a template to only expose the dome while it was sitting in the sun so as to minimize heat on the rest of the driver. A template could also be used while using the hair dryer too. I'll add some photos. For more information, there is a thread on this here somewhere "Yamaha NS-690 Mid Repair". I'll find it and post.
 
A couple of pics of the foam insert. This is a piece of soft foam from an old Advent speaker.
 

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One other thing about the mids, sometimes the VC leads will go open. I have a spare mid that read open but when I put the probes on the inside of the leads it read good. That VC wire lead is made of thin bronze foil wrapped around cotton thread. I located the break and was able to flow solder across the break. Fortunately that was a number of years back as the hands are not up to such tasks any more. :)

Another tip, brass door handles that tarnish. I used to polish them and spray them with clear lacquer. That would last maybe three or four months. This last time I used automotive clear coat, works like a charm.
 
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One other thing about the mids, sometimes the VC leads will go open. I have a spare mid that read open but when I put the probes on the inside of the leads it read good. That VC wire lead is made of thin bronze foil wrapped around cotton thread. I located the break and was able to flow solder across the break. Fortunately that was a number of years back as the hands are not up to such tasks any more. :)


Just happy you're still with us, Merrylander! Your knowledge here is such a wealth. :thmbsp:
 
Still hanging in there, switched over to photos and writing and trying to put a drop ceiling in the new playroom. So far I have four generations of framed photos on the playroom walls and 24 and a half chapters of a novel done. Tends to keep Alzheimer's at bay.
 
Merrylander, please PLEASE look into supplementation with alpha lipoic acid and acetyl l-carnitine.

I was asst mgr at GNC for 5 years, minor in athletic training, and this made a serious improvement in my friend's mom, who was late stage.

It will not interfere with any meds, and must be a combo of both. PM if you have any questions.
 
FWIW, a bud put me onto coconut oil. Any thots on that?

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FWIW, a bud put me onto coconut oil. Any thots on that?

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I seem to remember you had a bypass in 2005, or so, right?

Coconut oil is a fantastic source of good fats. Sold lots of it, many good reports. As with anything, do your homework, listen to your body. It boosts your HDL, as long as you use a reputable product, but I'd only use it once or twice a week. For cooking, alternate between it and olive oil, maybe 1 to 4 ratio (1 use of coconut oil to 4 uses of olive oil). Olive oil is still top dog for cooking in my book, but quality coconut oil shows great promise.

For heart probs, I always recommend quality omega 3's (no omega 6's tho, we get far too many, and our ratios are way out of whack) CoQ10 if you have a weak heart, or simply want more energy, and a quality multivitamin. Fiber mops up excess fats and cholesterol, so I always recommend that as well, plus it keeps the colon clean, and that's your escape route for funky stuff.

I haven't taken a B vitamin rich supplement in many months, and been dragging (working in the heat installing solar) and finally got back on my liquid B Complex (sublingual).

The return of natural energy has been amazing.


And now.....back to this amazing repair of a wonderful speaker. Wish I'd seen this before I sold my uglier pair (got a mint pair) to PhoenixFall.

Then again, I'd probably broken something. :yes:
 
A colleague in another forum, Ben Tongue of Blonder Tongue renound recommended CO Q-10 after my quad- bypass.
Back to NS-690 mid drivers, another fine speaker I don't have space for but can't bear letting go, like the DQ-20i.

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