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ar 2ax worthwhile restore?

simplynuts

simplynuts

Super Member
I picked up a set roadside that I haven't tested yet. Grills and nameplates look nice some scratches on cab that will disappear after light sanding. I read that the pots go south and usually this is why they get tossed. Is it better to replace them or find a resistor value that works and replace them if they are bad? Impression of these speakers? I owned or own large advents, klh sixes, dynaco a50 and 25 etc.
 
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I have a single AR2Ax for a mono system in my bedroom. It's one of my favorites....I really love it's colored, vintage sound, especially for jazz and vocal....(I prefer its sound to the Dynaco A25 and the Advents...the joys of having a separate midrange). Great bass and midrange.

You can bypass the bad pots by moving the center connection of the pot to one of the arms (one side will give you full output). The 4uf and 6uf caps probably should be replaced.
 
Check out Ozmoid's thread on restoring these puppies. They are incredible speakers. I went from Dynaco A-25 to pair of 1965 vintage 2AX's - the ones with the redish larger tweeter and non-foam surrounds. After '70 they updated them quite a bit changing tweeter, crossovers, then woofer. All interpretations are outstanding and very well worth putting the effort into fixing.

Don't pitch the pots till you get a look at them. If the corrosion isn't too bad you can use dremel with wire wheel and get them back to working condition - though they usually will have dead spots it's a way to try them as they were designed then tweak from there.

The later models moved from rock wool to fiberglass stuffing. The rock wool on the older models has high sulfur content and pots will be worse on these. Later model pots are usually very salvageable.

Good luck and enjoy. I think you'll be pleasantly supised at how ood these speakers are. Here's a pic of my babies completly original. Note older models had solid wood surrounding front edge.

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I like mine. I restored a pair along with some 4x. Make a great double stack if you get the chance.

Definitely get the old caps outa there. Bypass the pots. I really find they are useless. The 2ax is much smoother then the advents and the highs roll off early. They are a very non-fatiguing speaker, and I can't see a reason for needing to turn down the highs and mids
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I have the early version with the larger tweeter and the cloth woofer surrounds and I think they sound very nice. If you have any time it would be better to fix or replace the pots than to bypass. I used a 25 ohm rheostat (potentiometer) from Radio Shack and I think it sounds good. I didn't have time to do any extensive comparison with original pots, however. I wouldn't replace the caps if the speakers sound good. I replaced caps in one of mine and I don't notice any difference between that and the original.
 
I'm in the middle of restoring a pair. The foam on one woofer had dried & cracked but the other was fine - weird. One tweeter (black small dome) was dead. Pots seemed a little dirty but I haven't cleaned them yet.

The biggest hurdle was pulling the damn grill. Don't tear the grill cloth, break the grill board or gouge the cabinet. I mangled a number of kitchen implements before finding success.

Go to the thrift store and buy two thin butterknives. Take a pair of pliers and give one knife a little curl on the end so it can grab the grill when you pry. Use the hook knife to pry up the grill (near the top of the woofer) and before it slips down, insert the other knife next to the hook and slowly lift. The ancient glue should fail and the grill will pop up. Repeat on the other side then work your way up and down to pop the corner glue joints.

I love my AR-4 but these might steal the crown. I also have to restore a pair of Heath AS-2 which are more like the AR-2 with the double mids (all four are dead). GordonW says to replace them with a single cone mid.
 
I'll just throw in that I really, really like the pair of 2ax that I restored (completely refinished, refoamed, new poly caps, dremeled the pots). I run the tweeter pots at full out, the mid pots just a hair below full, and waffle back and forth on adding a slight treble boost on the tone controls. I made some 8" stands that dramatically improved the overall balance, though YMMV. I'm also feeding them 150wpc.

Worth restoring? Hell yes!
 
gonzothegreat said:
I also have to restore a pair of Heath AS-2 which are more like the AR-2 with the double mids (all four are dead). GordonW says to replace them with a single cone mid.
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Naw, go for the full resto......if not, you don't have Heath AS-2's anymore. I have some AR-2's that are nice to listen to. Full original in all their past glory.

Those double mids can be had for pretty cheap too.

Just my thoughts.......I like the vintage speakers to be original, warts and all, cause that's how they were :D
 
Thanks for the feedback guys. Now if my wife doesn't see that I snuck them in the house from the garage I might have a chance. Shacky my set looks identical to yours with the front edge, grill cloth and AR inc nameplates. These are much heavier than my original large advents anfd I think the cabs are not particle board. I will test them and let you guys know. I will put some pics up to too. I also want to restore a pair of allison cd6's i also found that need new surrounds. I played them low and was impressed by the bass from a small speaker. I have a guy I buy surrounds from who is selling out his stock, maybe I should buy him out and ask you guys what you need to pad down my inventory if I do. He charge me around $7 a pair for advent 10 inchers with some glue. This included shipping. anyone interested/ I have never had anyone complain about my repairs using his stock. I wold love to find out where these guys buy the surrounds that they make a killing on.
 
Good news that they are the older model. Surroounds should be cloth and can userubber cement to get good air seal again. On the down side if rock wool stuffing the pots may be worse than average wear.

I restored a later set with 4 screw woofer. While they are very good and probably more accurate, I like the older set up. Midrange is super sweet.

I first tried using 8 ohm l-pads to replace pots. Wasn't happy and went back in with set of cleaned up pots I got here at AK. The l-pads sounded like there was a hole in midrange. I'm far from an expert but my thought is the higher crossover points on older model are more suseptable to the change from original 15 ohm pots to 8 ohm l-pads. They do look like solid wood with veneer on all but front edge. The solid wood around front makes fixing dings a lot easier.
 
Shacky, I tried my set and neither mid or tweeter plays in both speakers. sounds like the pads died . I will try the trick to pull off the grill suggested earlier. Maybe they need a mild cleaning or wires came loose?
 
Simplynuts, Joe knows what he's talking about!!

Vast majority of the time, those pots are the problem. Massive corrosion causes the pots to add resistance where none was ever intended. End result is the mid and tweeter are starved for current.

Cleaning the pots is problematical as often the wipers are corroded so bad that little metal is left on the wipers.

The mod below will repair the problem permanently and actually move you closer to a flat frequency response on modern media (CD's, MP3's, DVD's, FM, etc.)

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Alternatively, if you really must have those controls, Roy has designed a very clever and a very cost effective substitute using 8 ohm L-pads:


Pot Solution

If you want to retain the ability to adjust frequency balance, Roy's solution is, IMHO, the best solution as well as the low cost solution. Modern pots, besides being very expensive, are often open in the back and I just don't like the idea of an exposed heat source in a closed box. Roy's solution will give you more than enough adjustment as typically you run the pots pretty close to full on. Final advantage is you lose essentially nothing in terms of power handling.

Hope this helps ....

Regards,
Jerry
 
simplynuts said:
Shacky, I tried my set and neither mid or tweeter plays in both speakers. sounds like the pads died . I will try the trick to pull off the grill suggested earlier. Maybe they need a mild cleaning or wires came loose?
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The pots are easy to take apart once you break into the cab. Follow Oxmoid's links to cleaning and breaking in. Whe you get to the pots and open them use the dremel with wire wheel. If they are too far gone you'll know - there will likely be holes and such in metal from heavy pitting. You will see lots of opinions on what to do if pots are shot. Also check out Classicspeakers.net. Depending on how much you want to invest in hese you can get aftermarket pots but they'll run at least $15 a piece and you need 4 of them. I'm a believer that the 15 ohm pots play a major role in the crossover ciruit and eliminating changes original design. But many here are happy with results of bypassing, eliminating or using 8 ohm L-Pads. YMMV.

Option Onplane mentioned modifying L-Pad to make them more like the 15 ohm pots sounds like good option though I have no experience. Pots (or Potentiometer, rheostats) are different in design than L-Pads.
 
I got the grill off but can't get the woofer out to get at the pots. The sapce around the woofer is tight and they use what looks like caulking to hold it in. I didn't do a great job on the first grill and cracked it pulling it off the second faired better. getting inside these speakers is like getting into Fort Knox. What is the trick to getting the woofer out? Thanks guys. anyone interested in buying surrounds for 6 8 and 10 inch speakers? My supplier is selling out his lot.
 
That caulk will give way - I used screwdriver in tight space around edge. Caredul it's easy to crack the wood. AR didn't design these to be easy. :no:

Too bad about the grill. Mine were already off when I bought them. But I see how much glue they used.
 
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