AR-2A Restoration-PICS

You can remove the crossover board from the cabinet. Trace the four corners so easier placement later.

I use a 5 gal bucket stirrer stick and a hammer to release the board. Tap gently moving around the outside slowly. Then it will be a snap to work on.
Use a screw and silicone to reattach once finished.
 
Thanks for the tip. I've been very careful not to touch anything if at all possible. When I took the grills off there was a ton of dust underneath. I used an air compressor (gently) to blow off the dust. Question - If the paper cones are that fragile, will they be able to produce decent sound? Or should they be replaced? Thanks for this thread - it's been invaluable for starting this project.
The mids will sound fine. You can also look on fleabay for a pair that were used in the Heathkit version, which hold up much better with age as I noted in the comparison pics. Another pair of AR mids will pretty much be in the same condition as yours. Either way, protect them.
 
Sorry for the late reply, life sometimes gets in the way. Just opened up the other speaker yesterday, serial #D8291, and found 3 more oil caps in it, but the sizes are different. Photos below. And yes, the grille cloth does have the gold thread in it - does that have any significance? Once again, thanks for your input and knowledge. As per Drugolf's suggestion, I'll be starting a new thread about replacing the pots for these speakers soon.
View attachment 1217911 View attachment 1217912 View attachment 1217913 View attachment 1217914

Very nice...and yes...the gold thread makes them more rare and desirable. I wouldn't mess with the oil caps at all. And yes...I tore a hole in a mid by just trying to clean it not realizing how fragile they are. Good luck on getting these nice babies sounding guuud!..;)
 
The 2As in this post were restored for me by GD70. You'll really enjoy them when they are done. Mine are in nearly daily use.
 
In the AR-3a restoration guide on Classic Speaker Pages, they suggest installing a .27-.33ohm resistor when replacing caps with modern metalized pp caps to match the ESR of the original caps. I'm recapping an early set of Heath AS-2A's. I haven't cracked them open yet, but the manual has paper looking caps, not oil. understand ESR but don't really understand crossover electronics well. I didn't see resistors installed in the original restore (sorry if I missed). Any advice on whether I need to do this here?
 
In the AR-3a restoration guide on Classic Speaker Pages, they suggest installing a .27-.33ohm resistor when replacing caps with modern metalized pp caps to match the ESR of the original caps. I'm recapping an early set of Heath AS-2A's. I haven't cracked them open yet, but the manual has paper looking caps, not oil. understand ESR but don't really understand crossover electronics well. I didn't see resistors installed in the original restore (sorry if I missed). Any advice on whether I need to do this here?
I didn't install resistors, just replaced the caps of the same values. They sounded very good when completed.
You could experiment, and temporarily install the resistors and listen with and without, and see which you prefer.
Glenn
 
In the AR-3a restoration guide on Classic Speaker Pages, they suggest installing a .27-.33ohm resistor when replacing caps with modern metalized pp caps to match the ESR of the original caps.
This is advice that might be worth adhering to for the 3a restoration, but generally I think you'd like to be able to tap into all of the performance from the aged and original tweet and mid of the 2a speaker. If your pots are cleaned and performing well, these would still allow you to dial back the high and mid frequencies. Modern film caps will work well here.
 
This is advice that might be worth adhering to for the 3a restoration, but generally I think you'd like to be able to tap into all of the performance from the aged and original tweet and mid of the 2a speaker. If your pots are cleaned and performing well, these would still allow you to dial back the high and mid frequencies. Modern film caps will work well here.

I am not exactly sure why anyone would want to preserve a high ESR for a cap in this application. The lower the ESR, the more efficient the cap and the less heat is produced in the process. Heat is wasted energy which leads to distortion. I would always go for the lowest ESR possible across the entire usable frequency band of the cap. My 2 cents.
 
I am not exactly sure why anyone would want to preserve a high ESR for a cap in this application.
Yeah, I basically agree with this, too, and my comment was meant to steer the conversation away from the 3a and back to the 2a which uses a very different tweeter and is even older than the 3a. On and on and on people debate the wonders that abound from various capacitor choices when re-capping vintage speakers, but rarely does the discussion acknowledge the diminished output that has occurred over time with these 50-year-old tweeters. As the tweeters have typically become more reticent with age, I agree that a cap choice exhibiting low ESR is probably a very wise move.
 
Yeah, I basically agree with this, too, and my comment was meant to steer the conversation away from the 3a and back to the 2a which uses a very different tweeter and is even older than the 3a. On and on and on people debate the wonders that abound from various capacitor choices when re-capping vintage speakers, but rarely does the discussion acknowledge the diminished output that has occurred over time with these 50-year-old tweeters. As the tweeters have typically become more reticent with age, I agree that a cap choice exhibiting low ESR is probably a very wise move.

100% agree. the components are 50 years old. following the design intent from 50 years ago probably won't result in aural time travel. Drivers are a wear item, they will perform differently from Day 1 to Day 10,001, caps aside.

Unless the owner of the system has a spec sheet of the drivers from the 1960s to compare yesterday's measurements to today's, then worrying about that factor is sort of a nonissue as well.

However, we do know what the cap values were, and we do know that caps degrade and the results can be measured. So, general practice of replacing caps with good quality parts is valid, in my book. How crazy someone goes costs is another story. But to my point above, I always try to seek a budget minded film cap with as low an ESR as possible, and one that maintains a relatively low level throughout the performance band it's being used in.
 
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Drivers are a wear item, they will perform differently from Day 1 to Day 10,001, caps aside.
Yep, your entire post #131 is terrific, and of all parts in a typical loudspeaker, I'd suggest that the drivers suffer the most obvious wear-n-tear. And yes, I've seen your justifications for cap choices with several projects, and your reasons are always well-founded and sensible with regards to budget.
 
I'm also replacing the tweeters with the HiVi Q1R from Parts-Express. Again, the consensus is to add a .07mh 18 gauge inductor in parallel with this to fit into the AR-3a design. (.05 is as close as I can get). Any thoughts on whether this is necessary on the AR-2A crossover? Or can I just dial back the pot?
 
Took a little over an hour to sand the cabs
Thanks for this Glen, it's very helpful.
A really basic question: what grit do you start with for stripping the veneer? I'm inclined to be conservative and start above 200 but perhaps that's too cautious.
 
Thanks for this Glen, it's very helpful.
A really basic question: what grit do you start with for stripping the veneer? I'm inclined to be conservative and start above 200 but perhaps that's too cautious.
Hey Scott,
I start with 220 grit, then go to 320. Go very slow and light with the palm sander.
Glenn
 
9E064326-3233-4D5D-9928-80D640E2D976.jpeg D47E2A58-E54D-4585-9B4E-DBBC08CB532C.jpeg Neighbor purchased at auction. Brought them over, can you say roached? Road kill? Cabs, speakers, pots...shot. On the plus side, they are AR 2A’s. Did open up and cross-overs appear intact and it was cureous the fiberglass insulation was in cubed squares and all covered in muslin cloth. So two questions, how do you get the grill off and secondly, is restoring worth it (beside personal satisfaction)? The one speaker with grill removed appeared to be table saw access. “Lovely”.
 
The grills are secured with small nails or staples- a lot of small nails or
staples.

They are definitely nice speakers when restored, but it depends on how
much "nice" is worth to the owner.
 
View attachment 1501732 View attachment 1501733 Neighbor purchased at auction. Brought them over, can you say roached? Road kill? Cabs, speakers, pots...shot. On the plus side, they are AR 2A’s. Did open up and cross-overs appear intact and it was cureous the fiberglass insulation was in cubed squares and all covered in muslin cloth. So two questions, how do you get the grill off and secondly, is restoring worth it (beside personal satisfaction)? The one speaker with grill removed appeared to be table saw access. “Lovely”.
That's a shame. They are a very nice sounding speaker when restored. I'd keep a look out for an empty cab in good shape and swap the drivers to the better cab, if you plan to work on these.
 
View attachment 1501732 View attachment 1501733 Neighbor purchased at auction. Brought them over, can you say roached? Road kill? Cabs, speakers, pots...shot. On the plus side, they are AR 2A’s. Did open up and cross-overs appear intact and it was cureous the fiberglass insulation was in cubed squares and all covered in muslin cloth. So two questions, how do you get the grill off and secondly, is restoring worth it (beside personal satisfaction)? The one speaker with grill removed appeared to be table saw access. “Lovely”.

well worthy of repair.
 
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