Ho Hum another AR-3a restoration

[kirk57]

Hi all-

I just wanted to post to introduce myself and say I've acquired some AR-3a (later ones circa 1973-4).

The restoration process has begun; so far, I've fixed some minor veneer dents using the water/steam trick, and stripped off the old finish which had darkened with age and cigarette smoke. I will use teak oil and Howard's Feed 'n' Wax to finish. I was quite happy with the results doing this with a pair of Rectilinear IIIs.

Woofers have been refoamed already. Next up, I need to replace the 150 uF NPE caps as one of them has drifted up to 166 uF (the other is still spot-on) and also will replace the 6 uF with Dayton films. The 50 uF caps are both within spec so I'll leave those, and may bypass the larger NPEs with small value Daytons. I know this affects the ESR of the caps, so I will measure the ESR first (yes, I have an ESR meter)

I intend to bypass the tweeter pots entirely. The midrange pots seem to be working OK; I'll give them a shot of de-oxit in any case. Grille cloth will need to be replaced, that I'll get from Carl. Badges are intact, just need cleaning.

I started my audiophile journey with Smaller Advents in 1976, and I currently also have AR 4x and KLH 17, a complete model 20 setup in my (fairly large)collection . The current main speakers are Rectilinear III which I like quite a lot. I do have other, more modern speakers (Dynaudio towers) but after putting the Rectilinears in the system for 'evaluation', they never left! I also spent a couple of years with large Magnepans, which I've concluded don't work very well in my listening room due to it's odd dimensions

2 questions:

- My main amp is a MacCormack DNA 1.0 Deluxe which is over 300 wpc into 4 ohms. I don't really listen at high levels much, so (assuming I don't do something stupid with sends a huge surge to the speakers) this should be OK? Is anybody using this much power with their AR-3a?

- I'm toying with the idea of fixing some padding, similar in concept to the 'acoustic blanket', to the front baffle, with cutouts for the mids and tweeters, to possibly realize improvements in imaging. Has anyone tried this approach?

Well, that's the story here. Just wanted to let you know another pair will be coming back from the dead.

Kirk

[Carlspeak]

Welcome aboard Kirk and good luck with your restoration.

I don't think your high power amps are a problem. The 3a's like some headroom to shine. If you are concerned, you may want to consider fusing the 3a's as a precautionary measure. The library has a comprehensive AR document how how to accomplish this. Fuses aren't 100% effective but possibly could save those valuable 3/4 inch dome tweeters.

The 3a's are a pretty laid back speaker. As such I don't think an acoutic blanket will help much. I haven't tried one myself. But there's no harm in you giving it a try. After all, this is a hobby. Experiment!