AR-3a How Old Are These?

[dualref]

I'm working on restoring a pair of -3a's I bought about 10 years ago at an estate sale. They were in pretty good condition but I noticed that the serial numbers are very low. 3a-8179 & 3a-8172. When I opened them up I found rock wool instead of fiberglass. And the capacitors were those big blocky things.

Anyone have a guess? Thanks..

[Carlspeak]

Have you downloaded and read the AR3a restoration document? There are pictures and descriptions in there of various vintage drivers used in the 3a that may help you not only understand your vintage, but also help you with your restoration. There's been over 26,000 downloads so far.

http://www.classicspeakerpages.net/library/acoustic_research/original_models_1954-1974/original_models_schematicss/restoring_the_ar-3a/

[dualref]

Yes, I have downloaded that document. It's very well written and contains just about everything you could want to know about restoring a 3a. And my speakers do conform to the photos he has of the early crossovers.

But I was just wondering if anyone could tell from the serial numbers what model year my speakers were from? That information is not included in that document.

[RoyC]

Yes, I have downloaded that document. It's very well written and contains just about everything you could want to know about restoring a 3a. And my speakers do conform to the photos he has of the early crossovers.

But I was just wondering if anyone could tell from the serial numbers what model year my speakers were from? That information is not included in that document.

Your speakers were manufactured in April or early May of 1968 according to data we collected while writing the restoration document.

Roy

[dualref]

Wow! These must be some of the earliest 3a's around. Forty-Three years old, now that's old. But I am happy to have them.

Roy, you wrote the restoration article? If so than a hearty congratulations to you. That was one of the best audio documents I have ever read. And so easy to understand too. AR up to the Teledyne buy out were my favorite speakers.

I am in the process of replacing the original caps with Solen caps of 3.0uF(x2) 50uF & 100uf. Do you think I should replace the wiring inside the cabinet too seeing as the wiring is so old?

[RoyC]

Wow! These must be some of the earliest 3a's around. Forty-Three years old, now that's old. But I am happy to have them.

Roy, you wrote the restoration article? If so than a hearty congratulations to you. That was one of the best audio documents I have ever read. And so easy to understand too. AR up to the Teledyne buy out were my favorite speakers.

I am in the process of replacing the original caps with Solen caps of 3.0uF(x2) 50uF & 100uf. Do you think I should replace the wiring inside the cabinet too seeing as the wiring is so old?

I was one of six, the others being Ken Kantor, Tom Tyson, John O’Hanlon, Bret Thiel, and Minh Luong. John was the editor, and deserves much credit for putting the information together and crafting the format..

The drivers in the AR cabinets are often stamped with dates, which will provide a good idea of when the speakers were manufactured...assuming the drivers have not been replaced along the way.

The wiring in the cabinet seldom needs replacement unless it has been cut too short, or replaced with lesser quality wire. The type of wire used, tinned marine wire, is still available in all of the original colors. (Btw, I have a stash of it for those who may need small amounts for repairs.) Just make sure there are no breaks.The pot area will require the most effort.

The large cap in the woofer circuit is 150uf, not 100uf. Feel free to send me a PM if you think I can be of assistance.

Roy

[dualref]

Thank you for that correction on the uF. I was typing off the top of my head when I wrote that. Since I can't find a multipart cap, I'm just going to separate 50uf & 150uf caps.

The only thing I have pulled out of my -3a's is the woofers. I haven't pulled the midrange or tweeter. I wasn't planning on removing them.

These 3a's are totally original and haven't been opened since new.

Thanks for the advice on the wiring. The wiring that's in there looks good. But it's nice to know what's used in case I cut something too short.

[danajohnhill]

Dualref,

Good on you for restoring your AR-3as. I, too, have a pair that, until I began their restoration a couple years ago, had not been open since 1969. Smart move leaving the mid-range and tweeter in place. I didn't touch mine, either. If your potentiometers are iffy, I recommend using a Dremel tool to clean them up. And you'll probably want to get some new putty before you close them back up. Good luck.

[dualref]

How did yours sound when you were done restoring them? Were you happy with the result?

Yes, I have the proper putty, new pots have already been installed. I cleaned the old ones up using a dremel, but about a year later they started acting up again so I replaced them, but didn't throw the old ones away. I learned a long time ago when dealing with things that are considered classics, never throw anything away!

I also bought an fiberglass insulation kit for the 3a. Mine originally had that rock wool and it was all at the bottom of the speaker. So I thought I'd upgrade it to fiberglass.

Since the original speaker cloth disintegrated when I removed it from the speaker, about a year ago I bought new speaker cover frames already covered in a fabric that is very close to the original. So when my LCR meter & new caps arrive, I am ready to start!

When I complete this project, I'll post photos if you all would like me to.

[danajohnhill]

I have no previous experience with AR products, so I don't have much to compare my 3as with. But I can say, compared with any other speaker I have owned personally, or used in my work [i am a radio host and producer, and as such spend all day listening to fancy studio monitors], the 3as are far and away my favorite speaker. Mine sound very full and rich, with a bass response that always makes me smile. Lots of people will tell you that the treble response isn't great, and I admit I have the tweeter turned all the way up on mine, but I don't think this is a severely limiting drawback. I have very good hearing [that is, I can still hear very high frequencies], and I don't feel the 3as make me miss a whole lot, treble-wise. How good are the mids? Well, when I was testing the speakers out following my restoration, I went into my CD collection and pulled out as many different kinds of music as I could find to sample. When I was playing Bringing It All Back Home, and "Mr. Tambourine Man" began I shot up in my seat. The acoustic guitar sounded so natural, so real, that I was genuinely amazed. I have played acoustic guitar in my living room a million times, and what I heard on that CD sounded live. I do have to pay attention to my speakers, though. A while back something didn't sound just right to me, and jiggling the tweeter pot made me realize that I had had a dropout. A little turn brought it back. No big deal.

[michiganpat]

Wow! These must be some of the earliest 3a's around. Forty-Three years old, now that's old. But I am happy to have them.

Roy, you wrote the restoration article? If so than a hearty congratulations to you. That was one of the best audio documents I have ever read. And so easy to understand too. AR up to the Teledyne buy out were my favorite speakers.

I am in the process of replacing the original caps with Solen caps of 3.0uF(x2) 50uF & 100uf. Do you think I should replace the wiring inside the cabinet too seeing as the wiring is so old?

The 3a was introduced the same year as the Teledyne buy-out....

I probably wouldn't mess with the wiring...of course, I wouldn't use poly film caps on the 150uF for sure, and probably not the 50uF either...

if I were to use something more than a decent NPE (like a bennic), I'd probably look at the erse PeX metalized polyesters, and buy 16 25uf and parallel them for the 50 and 150uf values, it would be $58 for all of them

http://www.erseaudio.com/Products/PEx250v/25uF-250-volt-Metallized-Polyester-Mylar-Film-Capacitor

[dualref]

6 25uF pots in one cabinet for the 150uf? And two more for the 50uf? Is there a reason for this that you think would sound better? I'm thinking in all those caps and connections there would be a lot of places for signal loss along the way.

And why would the NPE's be better than the poly film caps? This leads back to the "A capacitor is a capacitor is a capacitor" discussion.

Just wondering.

[michiganpat]

honestly, where the big value caps are in the crossover, I don't think 6 paralleled 25uf caps would sound any better or worse than 1 150uF poly or 1 150uf NPE...but that would be the most cost effective way to get all poly film caps, and you'd probably have tighter tolerance (at least printed on spec) than the NPE...

at the same token, I don't think you'd have much of an issue with signal loss, twist the 6 ends together, and solder them...

[Cereza]

dualref,

Congratulations on your restoration project! I won't give you my biological history, only a bit of my beloved AR-3a's. I bought them originally in 1969, I believe. I could pull out the original invoices, but I've since moved down from the bush of Alaska, Bristol Bay, where I had them shipped into. That was after almost 30 years there!

They've been loyal producers of all my vinyl through the AR-amp and turntable of that era. I don't have these two components anymore, but I wish I did!

I guess I will accept that the surrounds and pots probably need help, but my now 72 year old ears say, Naaaaaaaaaay, they're fine! [smile] So okay, you've given me the courage to open them up and see what they look like. I have downloaded the AR-3a restoration from this site and while it seems fairly easy, I'd prefer to let someone more expert than myself do it. Do you know any restoration businesses that would KNOW AND APPRECIATE WHAT THEY ARE WORKING WITH HERE?

Also, congratulations on the very, very early serial numbers! I had yet to read anyone who had any lower than mine, AR-3a numbers 21010 and 21959.

If you or anyone knows the date of manufacture on these, I certainly appreciate knowing. My original invoices would probably tell me that, but I'm relatively certain it'd be in 1968 or abouts.

Enough...love talking about AR speakers and gear! Just am now setting up a second generation of AR stuff...they'll have to shine to convince me they can outdo these beloved members of my family! [AR-9Ls--completely gone through and restored...beautiful}