Pioneer SX-1980 Exterior Restoration

[FireGuruMN]

A while back I finally bit the bullet and bought a Pioneer SX-1980 off ePray for too much money. It was sold as not working--for parts but "powers on". Which was fine with me. It showed up a bit later in far worse shape than the epray pictures. It was packed in a box the same size as the amplifier with shredded paper and pool noodles for packing material. There was shredded paper all over inside that amp. Eventually I got significant money back from the gorilla that packaged it and even went through the drama of filing a claim against FedEx since some FedEx had obviously tried to repair the package after the original shipping. But lets get past all that. Here is the beauty shot of how it turned out:

 

[FireGuruMN]

And don't worry, my favorite electronics repair god has gone through the entire electronic package and made it all just as nice. Entire new power supply from Canada. New filter caps (I tested the old ones and they still have tiny ESR and correct capacitance. Cool). All sorts of new transistor and capacitor thingies. . He even rounded up some missing knobs and feet.


But I'm not here to talk about the electronics. There are countless videos and posts that will do a far better job than I ever will. I'm talking WOOD. And even some METAL.
First the wood cover. My cover fell apart when I unscrewed it. And the finish was never going to recover so it was time to veneer. The cover lines up EXACTLY flush with the faceplate so it is not acceptable (to me) to just put veneer over the existing.
So I sanded the old veneer away. This would be super easy in a drum sander but I'm in a garage. So my choice was a random orbit 6" sander. 120 grit. The beauty is you know exactly when you have sanded off the old veneer because the color changes:
Then it was time to glue the pieces together. I highly suggest screwing the pieces to the amplifier so you know it will fit when the glue dries. The seams in the rough plywood
do not have to be tight because they are getting veneered over.

A little Gorilla taps is perfect to hold the joints together. Or you can temporary blocks for clamps but it's just a case, not a speaker. Notice the repair on the top. There was a shallow spot that I filled in with some scrap veneer and sanded. I could not get any wood putty or such to work there.
Continued. . .

 

[FireGuruMN]

I had a pretty deep gouge out of one of the mitered corners. So I tried some JBWeld wood putty/epoxy/goo.

I prepared the case by clamping a scrap of plywood with housewrap tape on it. Glue and stuff does not stick to this tape. I use it when pouring giant epoxy tables. So it must be good enough for this.

Cut off a small chunk and work it until the two material blend together into one color. Work it in with a putty knife.

Let it set and sand it up a little as needed. Takes about 2 hours to be sandable. Then it's just like wood. I fell in love with "quilted" or "figured" walnut when I was working on speakers and I have some scraps just big enough for this case. Don't use the figured stuff if you want a "traditional" look. Just get some plain old veneer. But I gave up on traditional a long time ago. I don't have pictures but lay the case out on your veneer and trace it out with about 1/4" extra all around. If you want a "waterfall" edge where the grain flows all around the case then go less than 1/4" if your dare. And yes, YOU DO WANT a waterfall edge. MARK each corner on the case and on the veneer on both sides of the case. It is not fun trying to match grain when everything is covered with glue. Choose a factory edge where the case meets the front faceplate. There is a "flange" in the wood on that side and I could not figure a way to router or cut off the veneer after it was glued on. And factory edges are always better. I was absolutely not in the mood for all the drama associated with contact cement so I chose to just use wood glue. That allowed me to exactly line up the factory edge when the time came. COVER the entire surface in glue. I used tite-bond number 2 I think. Any wood glue is fine.
I used my awesome Rockler glue spreader brush thingy I got for xmas. It was actually nice.

Get all your Rockler bandy clamps and a solid perfectly flat board ready. The board should not be too much wider than the case. Put the veneer in place and make sure all the glue is making contact and there are no nasty bumps. Then clamp it up:

Start with the sides. That way the visible edges of the veneer will be on the sides of the case. It seems trivial but in the end it is very noticeable (to me).
Continued. . .

 

[FireGuruMN]

Let the glue cure over night. There is a BIG difference between glue "setting up" and "curing". Always let it cure before working on it.
I trimmed off the majority of the excess with a scissors. I find that the router gets angry if the bit is making contact on both sides.

Then I used a flush trim bit on a little router. Set the bit as shallow as possible so that if you do not hold the router base perfectly flat you will minimize the gouge you take out of the veneer. The router bit will leave a tiny edge of paper that I clean up with a solid sanding block. Do not use a spongy block as it will dull the edge.

Then mask off the sides and glue up the top. The masking will keep the glue off the side veneer and also keep the bearing on the router from making any marks. I find all my bearings are glued up and I don't always notice when they are sticking.

You can see the flange in the above picture.
Glue on the top and use all the clamps you have to hold it in place. Let the clue cure and trim with a router. See if it still fits:

You can probably see the figuring in the walnut now. After 3 or so coats of poly that figure will become somewhat iridescent (if that is the right word). It seems to move when you view it at different angles. Waterfall edges!!

You can see why having the exposed veneer edge on the side is worth a little planning. Now it is time to drill out the screw holes that the veneer covered up. Use a tiny bit and mark the center of the hole from the back side of the case. Be as precise as possible. Maybe even use a brad point bit the size of the hold and just tap the tip through. I though of that just now. . .
Regardless you will not have enough thickness of veneer to hold your forstner bit centered. So drill a hole in a scrap board and use that to center the forstner bit as you are drilling. I think I used a bit that was a little too big. Measure yours first.

Continued. . .

 

[FireGuruMN]

A little glass work now. By some miracle the faceplate glass was not broken. But it was detached. So I scraped all the old blue off with a razor and polished it up and got ready to reattach it. I don't know what the brown goo was that they used to attach the glass originally. And I probably don't want to know that California thinks it causes cancer. I used this stuff:


Hopefully I won't need the mold protection.
Figure out which side is "up" on your glass. The hole for the tuning knob is not centered vertically. It's very close but not quite.

Just a few dabs:

If you get some squeezing out onto the glass, JUST LET IT DRY and cut if out with a razer blade. The metal faceplate automatically centers the glass vertically but there are no mechanical stops for left to right centering. So just line it up equally with the metal and all is well.

 

[FireGuruMN]

Time for some METAL!
Of course some of my heatsinks were broken. And some were bent. I was able to bend all my bent ones back to "straight enough" for the girls I go with. Yes, it is possible that they will break when you are trying to bend it back in to place. But if it breaks, it needed replacing anyway. .
Now, I am not a metal worker so be aware that your opinion of my skills is not welcome. Unless it is positive of course.
I did not take many pictures of the process so get ready for too many words. I had some scrap aluminum from an old HK receiver that I scrapped. It was just the right thinkness but I needed to taper it down to match the fins on the 1980. I have no metal working tools to speak of. But in many ways you can work with aluminum like wood. Just don't expect your blades to last too long. I started with an angle grinder to remove the bulk of the metal. Here is what I got to:

The finish if very rough. I held it up to the cracked fin and marked it with a sharpie. Then I used my band say (14tpi blade) to cut the profile. Then I took it to my bench belt sander and sanded it much smoother.

I considered using JB weld to attach it to the fin but I have no experience with that. But I do have a lot of "thick" superglue for wood working so I got out that bottle. I also have the "quick set" spray that will cure the glue in seconds.

Amazingly the glue seems to be holding very well. I was even able to use my belt sander to even out some of the edges where it was too tall. Then a few shots of spray paint and it's good to go. You have no idea how many times I went through how to do this repair. But in the end it all worked out. Until someone drops it again.
Continued. . .

 

[FireGuruMN]

Back to wood.
I don't know what evil was unleashed on these trim pieces. Like it was dragged across a green floor 100 feet?

I tried sanding them down but they got too small and the corners were rounded. And they are just blocks of wood so they got replaced:

Left side are the now ones I made and right side are the originals. The grain is clearer on the new ones I think. I cut these on a table saw and left them just a little too think and a little too long so I had enough material so I could sand them smooth. When ever you are going to have end grain exposed make sure you sand it to 240 or higher or it will look bad. Either way expect it to get way darker than the face of the wood so avoid getting stain on it if possible. I put poly on my ends BEFORE staining. Speaking of stain. I tried a few options and ended up with "light walnut" danish oil. I tried some "neutral" restoring oil but it looked bland. Imagine that. The light walnut warmed up the color just enough.


I let it setup over night. I had to bring the case inside with air conditioning because we are having a heat wave in October in Minnesota (they cancelled the marathon. OMG).
The humidity was preventing the stain from drying. Then I put on 3 coats of wipe on satin polyurethane. You do NOT have to use poly. It's just a personal preference for appearance and durability. Then it was time to find all my screws and knobs from 6 months ago.

 

[FireGuruMN]

In case you didn't believe me:

 

[FireGuruMN]

Just like all good projects. Two screws left over. Apparently they go on some switch places. I'm not dealing with it for now. And I ended up with one power knob (with out the plastic) instead of a mute knob. So I pulled on of of a SX-780 for now. I'll sort it out later.

Just some beauty shots:

I think I've got a loose LED by the tuning knob. Hmmm.


At some point I remember flattening out the bottom plate. It had more than Colorado. And a few shots of black spray paint on various pieces of sheet metal as I went along.

Now, if my audio hoarding spreadsheet is correct, I have the entire SX-??80 product line is my house somewhere. If I can find them all. 580, 680, 780, 880, 980, 1080, 1280, 1980. I'll have to get a family photo. I even have HPM-100, 60, 40 to include the cousins. Sorry, none of the SX-50 series. I like power meters!. But I hear the 50's are better built. . .

TTFN.

 

[Fairlane]

Beautiful work there. Truly a labor of love.
How does it sound now?

 

[FireGuruMN]

How does it sound now?

I'll let you know when I get it to the media room in the basement. For now its on the dining room table just so I can get on with other projects in the garage. I probably have to wait for my son to come over so we can 2 man lift it down the stairs. My bones don't work so well anymore.

 

[ivandezande]

Crazy to see what it started at to now!

 

[FireGuruMN]

I found them all! Woohoo!

 

[SDsailor7]

Beautiful work and beautiful receiver! congratulations!

 

[Watthour]

Great effort. The end result is it's own reward.

If you ever get into another one that has a damaged heat sink, there is a relatively easy way to repair it stronger than adhesive or epoxy, and maintain its thermal conductivity.

Of course, it could be TIG welded, but short of that it could be soldered/brazed at a low temperature with a specific alloy and flux, and the critical part of this is the flux. Since you stated earlier that you didn't care what California thinks about various chemicals (even though they know everything - just ask them) you would only need to provide sufficient ventilation to avoid their wrath.

I posted this previously for repairs that are stronger than the base material.

Repairing bent or broken external heatsink fins?

Yes. And its hard and brittle stuff. I'll fix it for the member.

audiokarma.org

Unless you constantly crank it up to eleven, what you have should work well to dissipate heat. As long as it doesn't warm up and soften the adhesive, it should hang in there, too.

 

[Blue Shadow]

I considered using JB weld to attach it to the fin

JBWeld is a good conductor of heat. That is what I would have used.

But what you have looks great, nice work.

 

[gallileo60]

Wow, you did some truly amazing wood work, I wish i had a tenth of your skill...Some of you guys really know your $hit, and it shows...Some many beautiful Pioneers, so little time, and money....Congrats.....Tom

 

[rulnacco]

I found them all! Woohoo!

Holy mother of god! What a set. I'm totally envious. Congrats!! Oh, and the restoration on that 1980 was top-notch, too.

 

[TomSc]

Very nice work and that's an amazing stack of silver Pioneer!