AR-2A Question/Dulling Sound

[john5]

I recently came into two 1962 AR-2as, and neither worked from the usual potentiometer problems. I opened one up two weeks or so ago and resoldered the two leads connecting to each pot's wiper to connection #1, and once put back together it sounded great just listening in mono for about 5 days. Now, a couple of weeks later, I feel the very top end is really rolled off, and I'm a little perplexed as to what to do first since I've read the caps inside shouldn't be replaced, but I'm wondering if them potentially failing could cause this to happen.

I'd love to not have to open this one back up but will if I have to, of course. I have no way to measure response but I'm pretty certain the overall sound has changed and become slightly more warm over two weeks, without the top end snap they had when I first worked on them. Where should I start?

I'd almost swear the sound changed when I installed the grille cloth, which is the 18 Count Lambswool Linen recommended elsewhere on the internet for AR restorations, but I'm hesitant to rip the front off again just to see.

(And, yes - I'll get the LPs off the edge before they warp, that was temporary.)

[RoyC]

Welcome to CSP, John...

Assuming everything is OK with your amp and associated electronics, there is no way to even begin checking out your speakers without removing the grills. Being hesitant to "rip the front off again" suggests you may have glued them on. Hope not...Velcro is your friend in the world of AR restorations.

Are your tweeters functioning? Are the jumpers connected properly on the 2as' rear terminals? Do both speakers sound the same? If they sounded acceptable at first, it is not at all likely the capacitors are suddenly causing the "rolled off" issue you describe. The grill cloth you used is the best available, and not known to cause the issue either.

I'm not clear as to what you did with the pots. The 2a's tweeter pots are connected to 3 wires, and the dual midrange driver pots are connected to two (with one unused terminal).

Roy

[john5]

No, I'd used carpet tape and then just reinserted the frame, but it buckled somewhat when I initially took it out and then worsened when I finally removed it again yesterday...was just hoping to avoid removing them. As it's turned out, it was the grille cloth, maybe my ears just got used to hearing them without and I didn't like the sound with them in front of the tweeter. Not pretty, but happily listening again without the cloth!