AR3a Restoration capacitor question

[Kendall]

I am starting a restoration of a circa 1975 AR3a pair of speakers. I’m hoping a good cleaning of the pots will make all the mids and hi’s work all the time. I will also replace all the capacitors and my question is it a bad idea to replace the 6.0uF Sprague (AR/E/8095 6-50VNP) cap with a 6.2uF 250V Dayton? At least at Parts Express I’m not having any luck finding a 6.0uF cap. Thanks in advance!

 

[gkimeng]

Sprague Compulytics have been tested and found to still be within spec. Unless the can shows signs of swelling or leakage, you can leave it be.

 

[GD70]

I'd replace those. I restored a set a couple years ago, and the Spragues were pretty far out of spec, to my surprise.
Go with these. You'll be fine. Roy C., who is one of the co-authors of the AR-3a restoration guide told me this is what he uses in his restorations.

Glenn

 

[macyjrm]

If you plan to keep them, I believe replacing the pots would be wise. They are a well known weak point in the various AR speakers of this vintage. It would be a shame to go through all the effort to remove the woofers and pots, properly clean the pots, replace the caps, and then reinstall all correctly only to have the pots go bad soon again. Trust the voice of experience. I also believe the new pots allow a little more sparkle on the high frequency spectrum.

 

[Kendall]

If you plan to keep them, I believe replacing the pots would be wise. They are a well known weak point in the various AR speakers of this vintage. It would be a shame to go through all the effort to remove the woofers and pots, properly clean the pots, replace the caps, and then reinstall all correctly only to have the pots go bad soon again. Trust the voice of experience. I also believe the new pots allow a little more sparkle on the high frequency spectrum.

What would you suggest as a replacement? It seems like it is nigh impossible to get an exact replacement these days. Not sure if I want to go the L-pad route either. Thanks!

 

[macyjrm]

There is an excellent vendor on eBay (no affiliation) by name of vintage-ar. He offers multiple vintage AR items including replacement pots for various AR models. I have three different model pairs of ARs and they all contain at least a few items from his stash. I’m satisfied completely. Not cheap but good quality and service.

 

[Kendall]

I'd replace those. I restored a set a couple years ago, and the Spragues were pretty far out of spec, to my surprise.
Go with these. You'll be fine. Roy C., who is one of the co-authors of the AR-3a restoration guide told me this is what he uses in his restorations.

Glenn
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Thanks Glenn, I found the 6.0uF caps at Madisonsound and will return the 6.2’s I ordered from PE.