Hi all,

I'm beginning the process of recapping my SP-3500 speakers and I have the first crossover out and I've noticed that on the tone controls for the mid/high-range there's something...I don't know what it is.

It kind of looks like corrosion but it sort of rubs off with my finger. it also kind of scrapes off with a pocket knife, but before I actually removed any meaningful amount I figured I better make sure its not grease or somehow otherwise supposed to be there. I kinda think it might be grease, since there's bare nice metal under it, but...I dunno...a second opinion is good. I know I read a thread recommending a de-oxit cleaning of those pots, but I don't have any and forgot to order some with my last partsexpress order...I assume this would remove whatever this is, grease, corrosion, or otherwise.

I've attached a peek-ture! (apologies for the horrible cell-phone pic, but it's all I have here) Hopefully someone can tell what I'm talking about :)

http://i30.tinypic.com/eb651y.jpg

sorry, had to use tinypic because for some reason firefox isn't handling the picture form redirect/pop up properly

Thanks!

Well, I finished the recap! Everything works great and now I'm much more impressed with the sound of these monsters. Before, the midrange seemed really harsh and overbearing to me and now it's much smoother - I was listening to some of my more articulate metal like Ayreon and Borknagar and let me say these are the best sounding pair of speakers I have right now - let me tell you, the way the tweeters and midranges are set up really produces the most believable stereo imaging of any of the stuff I have.

The bass didn't really improve much, but then again, that's for the best since I live in an apartment and my neighbors probably already hate me.

For the record, I used:

Jantzen 15uF 400V Crosscap (Parts Express # 027-936) x 2
Jantzen 2.2uF 400V Z-Standard Capacitor (Parts Express # 027-266) x 2
Jantzen 4.7uF 400V Z-Standard Capacitor (Parts Express # 027-274) x 4

Certainly well worth the cost of the upgrade!

I'm still curious about the weird stuff on the tone controls, though...disassembling them again wouldn't take long...hopefully alcohol and q-tips can clean whatever it is off of them if I do indeed need to clean them...

I have recapped eight pairs of Sansui SP-3500's now and all but one pair had the same stuff you mention. Its just oxidation. I use some deoxit on a mascara brush to remove the better part of it. The only important area to remove it from is where the wipers actually touch the metal below.

If you look close you will see a very small solid copper line where the actual contact takes place. That is, unless, you or the previous owner never fiddled with the tone controls and kept them all in one place.

Here was my cart for the last recap:

2 027-536 SOLEN 2.2uF-400VDC POLYPROPYLENE CAPACITOR
4 027-552 SOLEN 4.7uF-400VDC POLYPROPYLENE CAPACITOR
2 027-576 SOLEN 15.0uF-400VDC POLYPROPYLENE CAPACITOR

ps It's awesome that yours have that original tag coming out from the emblems. None that I have seen in person still have that! I am sure it will increase the volume if you ever go to sell them.

Here is some literature you might want to include too - maybe a color laser copy laminated would be good to keep with them.
http://www.classicsansui.net/images/Literature/Speakers/SP3500%201.jpg
http://www.classicsansui.net/images/Literature/Speakers/SP3500%202.jpg

That was kind of what I was thinking...until it kind of rubbed off like grease on my fingers. Still, I'll be getting it out of there next chance I get.

Thanks, and the vintage literature is pretty sweet!

Oh, and I love the tag, too! Only one of them still has it, but it's definitely neato. The grilles are in pretty sad shape and the cabinets have a few more than their fair share of scratches and scuffs - I think the previous owner had been storing them in their garage for...probably a long time. The drivers are all in great shape; only had to re-glue one of the woofer surrounds right after I got them (one must have been subject to much more sunlight or something for the glue to fail on only one).

They'll probably not ever be worth any money, but they rock, and they were cheap ($35 on CL)!

Thats a great deal. They go for around $200 on eBay.

I have on several occasions removed the grilles and sanded them down to bare wood and then repainted them. I use brown spraypaint but you could also restain them if you are so inclined.

On two pair I ripped off the foul brown grille cloth and replaced it with a nice deep burgundy grille cloth. Drastically increased the WAF because they then matched the bedroom color scheme.

The things we do for love... ;)

Yeah, I'd love to do that with the grilles, but the problem isn't so simple - mine are actually missing some pieces (probably about 6-10 little chunks out of the lattice on each one). What's left is still also a candidate for refinishing.

If I were a competent woodworker, maybe I could fashion some pieces that looked close enough to put in there and stain the same color and maybe you wouldn't be able to notice. Oh well, though, they seem to sound a little better sans grilles and with the screws they're a pain to take on and off anyway. If I ever do try to restore them, you can be sure I'd be buying one of those grille magnet kits :D