Restoring my DIY AR-3a Pair

[DonQuixote99]

The Heath cabinets are more decorative on the outside, but once you get the woofers out you'll see that they aren't as heavily braced on the inside as AR's version. The Heath kit versions were sold at lower price points than their AR equivalents, and since they used the same drivers and almost the same crossover components (the Heaths used different caps), the cost reductions were almost all in the cabinetry.

And in assembly labor....

But adding a bit of bracing sounds like a plan.

 

[GD70]

Back to this project a little. My plan is to try to acquire someone's dead midrange, so I can get the grill and damping off it to restore that one of mine to a condition matching the other.

And it looks like the tweeter solution is to buy a pair of the HiVi tweeters, prob from Parts Express: http://www.parts-express.com/hivi-q1r-1-1-8-textile-dome-tweeter--297-417

BUT I'm not sure what size inductor to put in parallel with it. Parts Express and some folks here say .07mh 18 guage (and I assume guage isn't critical). Other people here, however, say .05mh? Is there a current consensus on that inductor spec?

And too, I haven't totally dismissed the idea of these more expensive drivers, "Factory Acoustic Research Speaker Dome Tweeter Part # 12000840 (12151300)," available from Simply Speakers: http://www.simplyspeakers.com/acoustic-research-replacement-tweeter-12000840.html

I'm attracted to the higher power-handling capability of these, but I don't like the extensive list of applications. How can the same part be right for all those different speakers?

Contact Roy C. about the HiVi tweeter swap and inductor coil, may need a cap as well.

I used them in my LST-2 restoration, which needed 6 tweeters! I had to swap a cap out as well. They sound great, and Roy said were the close to the original sound.

Glenn

 

[centsless]

The Heath cabinets are more decorative on the outside, but once you get the woofers out you'll see that they aren't as heavily braced on the inside as AR's version. The Heath kit versions were sold at lower price points than their AR equivalents, and since they used the same drivers and almost the same crossover components (the Heaths used different caps), the cost reductions were almost all in the cabinetry.

That is untrue. I have both and the quality is superb. The difference in price was the Heathkit came as a kit..and the buyer assembled the parts with a detailed manual. The cabs came from a furniture maker.

I like the idea of a home novice...(got my mint set from a retired electrical engineer)..putting together a pair of speakers with love and care and everything done precisely....and love having the manual showing his checkpoints marked off...great history with it.

I have done six to seven sets of AR3's and A's and I got to tell ya.....the craftmanship from the factory workers was questionable in some of the pairs I had....such as tweeters with bent tabs at screws where it wasn't set properly in the recessed hole. The recessed hole for the tweeter is off to the side on some pairs... just things done that an assembly line worker would do.

 

[DonQuixote99]

Contact Roy C. about the HiVi tweeter swap and inductor coil, may need a cap as well.

I used them in my LST-2 restoration, which needed 6 tweeters! I had to swap a cap out as well. They sound great, and Roy said were the close to the original sound.

Glenn

I took this advice, and Mr. Roy's been kind enough to answer back. The answer is .05 *or* .07, with .07 giving more forward tweeter sound.

BTW, one would want a .1mh inductor with the Simply Speakers offering, which is the GFA tweeter.

 

[DonQuixote99]

Midrange Grill Transplant

My naked midrange is now properly damped and grilled. Big Good Karma to the two AKers who cooperated to fix me up with a dead donor unit for free!

Pics show:

1. My working midrange as it came to me:

2. Grill 1/2 removed from donor unit. I used heat from hairdryer to soften glue, and just pryed around with small screwdriver.

3. The removed grill, from back. It was held-on by either by epoxy or a sort of plastic tape, can't really say. There's paper underneath.

4. Damping still stuck to donor unit. It's just a fluffy little disk of fiberglass, compressed some by the grill when it's on. I just pulled it off and rubber-cemented it on to the working midrange.

5. Working midrange with its new grill glued-on. Used Aleene's Tacky Glue. Prepared grill for reattachment by picking off large bits of old attachment, and then flattening flange with hammer and anvil.

The project continues....

 

[GD70]

Looks great! Pics are invaluable for future use by others with the same dilemma.

Glenn

 

[Fairlane]

Great work!

Any of us could need your midrange repair guide down the road
Kudos to the members that helped with the donor unit!

 

[DonQuixote99]

Thank-you gents. There was nothing about this that was any sort of a technical challenge, or required special crafty skill or anything. But I did have to bravely venture into undocumented ground, as far as I could find. So I fixed that.

 

[gkimeng]

I have both and the quality is superb.

I doubt anyone would notice the difference. ARs were always very overdesigned structurally, and since Heath's relationship with AR was no secret, neither company would have wanted the end product to be noticeably inferior.

Kits were never really about savings, but about the DIY hobby. The cost of putting together the kit with its consumer-friendly packaging and instruction manuals, and the cost of maintaining the kind of builder support that Heath used to provide in its heyday would have more than made up for the difference in assembly labor. Of course, AR also spent a lot on their customer support, paying for shipping of defective speakers both ways and doing the repair work (Heath would have just sent replacements for defective parts), so it may all have evened up in the end. And assuming the hobbyist was reasonably competent, there's no replacement for the kind of care that goes into building something that's going to be yours.