Restoring my 3's

[ar_pro]

Clean, and neat...nice work, David.

[VintageMan]

This week I will be working on my AR3a's.

I hope I'm going to be just as pleased with mine as you are with yours

Nice job!

What did you use as a spacer for the L-pads?

[DavidDru]

Spacer.. Clarify spacer. Where? There is a washer between the lpad and the wood.

[DavidDru]

Clean, and neat...nice work, David.

I moved the wires around a bit to straighten it up more after taking the photo but the new size of the lPads does change things up a bit. I really couldn't fit the resistors on the crossover, but no biggy.

[VintageMan]

Spacer.. Clarify spacer. Where? There is a washer between the lpad and the wood.

That is what I mean

[owlsplace]

I moved the wires around a bit to straighten it up more after taking the photo but the new size of the lPads does change things up a bit. I really couldn't fit the resistors on the crossover, but no biggy.

Were the pots originally wired using female spade connectors or soldered?

[DavidDru]

Were the pots originally wired using female spade connectors or soldered?

Soldered.

[DavidDru]

Nice work.

I spied an Allison One in the photo. How do those sound?

The Allisons are very nice. Very important to get the most out of them is to position them in the room correctly. I'm close.

[JKent]

What did you use as a spacer for the L-pads?

Your L-Pads are from Madisound: https://www.madisoundspeakerstore.com/l-pads-attenuators/yung-lp15-3/4-15w-8-ohm-l-pad/

Unlike the ones from PE, which have a 3/8" (9.5mm) shaft the ones from Mad have 3/4" (19mm) shafts.

So... You will need a spacer, about 10mm thick.

Also, you have to be careful of how you wire the L-pads. There are diagrams posted here someplace but I'll email instructions to you.

-Kent

PS: Here's a photo from Roy showing how to wire the L-pad (and one option for attaching the resistor). Roy explains it best, as follows:

When using an l-pad, it is important to make sure the original polarity is observed. Below are photos showing the original AR-3a midrange pot and a replacement l-pad with the appropriate connections. The original pot terminals and the replacement l-pad terminals are labeled differently (1, B, 2 for the pot and 3,2,1 for the l-pad). I have indicated the corresponding pot tabs on the l-pad. This is how l-pads would be connected with or without the added resistor.

Adding the resistor as shown between the l-pad's #2 and #1 tabs is the same as placing it on the back of the driver (mid or tweeter) and connecting it between the + and - terminals. The resistor simply changes the circuit impedance to make the l-pad duplicate pot settings between *just off* maximum to about 1/2 revolution back. The "white dot" setting is easily emulated, and the required 15 to 16 ohms across the + and - side of the level control is maintained. (The resistor can also be placed between the tabs on the front of the cabinet for front-wired models.) My personal preference is a straight l-pad on the tweeter (no resistor) for slightly greater tweeter output, and the original pot or l-pad/25 ohm resistor arrangement on the mid.

The only real concern when using l-pads is that the "maximum" setting removes the series and parallel resistance, consequently directing more power to the drivers, so care must be taken if the user's preferred setting happens to be maximum/fully increased.

[DavidDru]

So yes, mine is wired as shown in that attachment of JKents on the right. Of course there are 2 yellow wires on each of these and as I stated for whatever reason my resistor is physically larger and can't quite reach back to both posts from a mountable location so I combined the yellows and one end of the resistor with an added pigtail which then connects to post 1. Moral of the story here is if you can find the smaller mills resistors, maybe go that route. Overall not difficult, just need to think and map it out including mounting location, wire lengths etc. As far as orientation of the LPad I am figuring it does not matter because I will just attach the knobs to the shaft in the correct alignment on the back.

Thanks for the added info JKent. I was wondering how adding a resistor made the LPad extend from 0-8 up to the 0-16 of the original pots. Had planned to ask.

[DavidDru]

Finished #2 yesterday! Listened to both for a while before a rather large lightning storm came barreling in so I unplugged all my gear just in case. Nice. It may have just been me but it sounded to me like #2 needed to open up a bit and catch up to #1 that I used for a couple hours already the night before. As the listening went on for the hour I had them both going it seemed to be less obvious. Unless of course my tweeter is a little weaker on that side or something. I set the lpads at the middle on each and didn't fool with them for now.

I will give them a much more intensive run later this week. I am off to Washington for a little business and where I also happen to have found a pair of rare speakers I am picking up.

[owlsplace]

...

I will give them a much more intensive run later this week. I am off to Washington for a little business and where I also happen to have found a pair of rare speakers I am picking up.

Good decision on ditching the original pots judging by the verdigris on the connectors. Hope the Washington escapade is rewarding

Roger

[DavidDru]

Well, it's official. I am a proud owner of a working restored pair of AR3's! And boy do they sound good.

I been fooling around with the wiring and reconnection of the mids that Roy fixed and had found for me and ended up with issues. Upon putting them back together a few months ago with the LPads, something sounded wrong. Sure enough it turned out one of the leads on the mid range was broken and barely holding on just under the screen. It would come on and go off etc. It took me a while to figure it out and once I did I sent it off to Roy and he quickly did his thing and sent it back. (Thanks Roy)

In the meantime I got busy with other stuff with the family as summers often do when you have kids and I just wasn't able to spend any quality time getting the speakers back together. I was able to dig in a few times over the last couple weeks and finally got it all back together last night.

I kept going back and forth on weather or not to solder the wires to the LPad or not and ended up doing it. Adding the resistors made things a bit cumbersome with some rather big wire connections so soldering where I could was actually helpful once I figured out the best way to lay it all out with the added resistors and the Lpads that are larger than the pots.

I decided not to add a resistor in line with the tweeter based on a recommendation from Roy. His thought is these old tweeters need a little help so no need to throttle things back by adding a resistor.

All that's left are the grilles as described earlier in the thread. Stands too. I will post pictures soon although I didn't take any as I put the crossover and wiring all back together this last attempt. Oops.

More listening impressions too after I let them run a couple days on the new caps. Although they sound damn good already.

[VintageMan]

Don't you just L.O.V.E those AR3's?

I did the same with mine and only added the resistor to the mid's.

Also made stands based on the original, but then 60cm high.

[DavidDru]

I brought this up earlier in the process but now for the repair of the grille frames that had been broken on one end each prior my acquisition of them (see how I blamed someone else there).

I need ideas from the treehouse here. Jeff (lakecat) had some success with the Gorilla plastic glue and a section of coat hanger. Seems to make sense and I will start there.

Seems to me the fabric pulls pretty good on the frame. I would rather not take it off if I don't have to since I am trying to save it as original.

[JKent]

Agree--don't take it off. AND be very careful with the glue. I have not used Gorilla plastic glue (did not even know about it). Think I used Plas-T-Pair, which worked well (it welds the plastic). BUT when I re-attached the saran to the plastic frame, using Aleene's 7800, some got onto the grille material (saran) and left a stain.

-Kent

[DavidDru]

Point taken Kent. I picked up a similar product to what you used to "weld" it in J-B Weld. I will probably use some wax paper in the area to protect it from going where I don't want it to. Trick is finding a bonding material(glue) that works strong on plastic and metal.

I picked up a piece of threaded steel rod (like a machine screw) to use as a splint.

I'll take some photos when I do it today. Yesterday ended up raking leaves and prepping yard for the coming winter months. Yeah!

[JKent]

I picked up a similar product to what you used to "weld" it in J-B Weld.

J-B Weld is an excellent epoxy product. I use that often and I like their "Wood Weld" for cabinet repair. But Plas-T-Pair is different. It's a solvent-based product, like model airplane glue, that dissolves the plastic so when you join 2 pieces the plastic is literally welded in a way analogous to welding metal.

Steel rod sounds like overkill to me. I think Masonite or wood would be sufficient.

Just my 2 cents.

Kent

[DavidDru]

The melt and bond thing is what most of the PVC pipe glue does we use in irrigation work. Wonder if it really any different than that Pas-t-pair stuff you found. hmmm.

I also wonder if we couldn't just melt and reform the area of the crack with an old soldering tip. First line it up with clamps and melt away?

The metal rod is only a little thicker than a hanger. Just wanted something a bit more rigid.

[DavidDru]

In trying to get a good clamp on the frame, the saran fabric is making things very difficult. It is so taught that it bends the frame a bit and pulls on the end just enough that it is hard to get a good straight alignment with the clamps. Do you guys usually take the fabric off to do this?

[rjr513]

imho I think you better off to replace with new frames and saran maybe Kent has some extra saran left from original order, you can pm Kent for details also see Kents documentation on installing the AR3 grille attached.

Replacing the AR3 Grille 4.pdf

[DavidDru]

So I went ahead and built new frames. Now, has anyone re-used the old saran? Mine are in good shape and will just fit on the frames I built after taking them off the old plastic frames carefully. What ya think?

I did get some new mellotone fabric from JKent, but it is of course white while the old is brown/gold.

[K6cdxkms]

I did not post this on my rebuild ,however for those of you out there that are redoing the pots ,

after you clean the pots, place them in strong alcohol and let them sit in the solution for a couple of hours.

This will dissolve the rosin from the solder joint that has leached down into the ceramic which is causing the corrosion.

One other point after soldering is done on the pots you need to wash them again to remove the left over rosin again.

This means that you do all of the soldering on the pots when they are broken apart ,the after soaking and drying rebuild with silicon grease for lube,

One other point , the wire resistor will not be smooth as an new style pot, it is a wound wire that only has ~0.2-0.4 ohm diff from wound wire to wound wire.

Just some food for thought.

V/R,

Ken

[GD70]

Just read through the thread and your 3's look gorgeous! Very nice work!

How are the grills coming along?

When I was restoring my 3's, I contacted Kent about the original grill fabric, but ended up not getting it. My grills have the 3A linen fabric and decided to leave them as is.

I'm usually a stickler for originality, so may decide to get some of the fabric and make a set of grills at some point.

Glenn

[GD70]

Thoughts on your original grill repairs, if you haven't done them yet.

Since the fabric has session, pulling the short sides in, try using a piece of wood to gently push them back out to original position,maybe using a hair dryer at a safe distance to soften the fabric a bit to make stretching it easier.

Once in original shape, I would sand the plastic frame surfaces, use epoxy and a small amount of light fiberglass as extra support. It won't be too thick, but verystrong. Once cured, remove the wood support..I also would place wax paper between the frame and grill fabric.

Good luck!

Glenn