AR 3a pick up

[xmas111]

I'll be picking these up tomorrow. I think it's a pretty good bargin.

I'll post again tomorrow after I have them and have a little time to study them.

Always want a set of AR 3a's.

http://johnsweather....posts/ar3a.html

John

[Darrell Peart]

If they are in fact in good shape, I am sure you will more than enjoy them. I have a pair of 3'as set up in my office that I listen to everyday and love !

[xmas111]

Ok, they sound pretty good so far. The woofers have been refoamed and the pots have been replaced. Actually the seller said he replaced the pots and I have no reason to not beleive him. Now I have to decide if I want to rip them apart and replace the crossovers components.

The cabinets are not in great shape but not terrible either. I'll have to decide what I want to do with them later. Just want to listen to them for a little while first.

I'm driving them with a Yaqin MC-100B amp. Not the most power amp but it seems to be pushing them pretty good so far.

John

[dick]

Haven't been on here in many months. Your situation brings me out of the backroom....

The back of the one speaker is regular plywood - see the grain? -- not pressed chips--the incredibly dense wood of the original, and not original as is the other one?? Probably no big deal as long as it is dense plywood, but what plywood today is without gaps other than marine grade? As for pots and other improvements, see Roy C -- my long term seriously guiding speaker guru. Speakers here have L-pads, and Hi Vi tweeters that well might be now out of stock and gone forever--but check out Madison Sound -- the T20-4 tweeters. These tweeters put the 3a's firmly in Speaker Heaven in my not so humbled earful opinion. Not that I'd recommend them <oh yes I do!> -- I have an extra pair tucked away for the day when the current ones fade away. But, no reason to totally despair, there are other HiVi options in case the T20-4's are gone. Also, a NAD 372 amplifier does the job here -- we're vastly pleased. But we'd never over-amp the speakers...they're just too precious. 18 ga. AR speaker wire. Faure piano works now on and sending me, so.... Gotta go listen.

Count your luck stars re: landing a 3a -- I count mine daily!

[Darrell Peart]

The back of the one speaker is regular plywood - see the grain? -- not pressed chips--the incredibly dense wood of the original, and not original as is the other one?? Probably no big deal as long as it is dense plywood, but what plywood today is without gaps other than marine grade?

I believe both cabinets are the same - one has just been sanded clean. Both have particleboard cases and I assume particle board backs - although we can't see to verify that.

It appears that AR-LST's (or 2) in the background. I would like to hear your opinion of how they compare to the 3a’s. I have never heard a pair of LST’s. Because of faceted fronts - I wonder if the LST might have similarities with the Allison One’s ?

[xmas111]

Yes both cabs look the same, the flash from the photo was aimed right at the one speaker making it looks lighter.

Those are LST2's in the background. (I can hope and pray and get some LST's one day... )

I have to say the sound is completely different from the LST2's compared to the 3a's. The LST2's have a much brighter sound, maybe because of the three tweeters and mids compared to the single tweeter and mid in the 3a's.

Both have great sound!

I plan on recapping the 3a's and what else is suggested the the AR 3a Restoration manual. That manual is fantastic, what a great job they did putting it together!

Will see how they compare after restoring the 3a's.

I also have a set of AR9's that I have hooked up to my main system......nothing compares to those monsters!

I'll take pictures when I get the 3a's apart to get everyones opinion on what I should or shouldn't do to them.

I've never heard the Allison One’s so unfortuntely I can't commet on how the LST2's compare.

John

[xmas111]

Thought I would pass this by you guys.

These are the caps and coil I plan on using to rebuild the crossovers.

The valus I got from the AR 3a Restoration Maual.

150mf ----Solen 150 mfd Fast Cap 400V http://www.madisound...-fast-cap-400v/

50mf ------Solen 50 mfd Fast Cap 400V http://www.madisound...-fast-cap-400v/

6mf ------- Solen 6 mfd Fast Cap 400V http://www.madisound...-fast-cap-400v/

I don't know for sure but I'm assuming I have the #7 coil, 1.88 mH so I'll add this one in series to get 2.88mH coil.

1.0 mH coil ------Jantzen 1.0mH 18 AWG Air Core Inductor http://www.parts-exp...r=255-250&DID=7

Does everything look suitable?

Thanks guys,

John

[JKent]

You can get Erse PulseX caps in 6uF, 51uF (close enough) and 150uF. Very nice caps and less expensive than the Solens. The Erse site also sells good air core coils for less than PE. Get all your stuff from Erse and just pay one shipping charge: http://www.erseaudio.com/

150uF film caps are expensive. The Solens are over $40 each, the PulseX are over $38. Some restorers use NPEs for the woofer caps. You could use the Erse film caps for the mids and tweets, but use these 150uF NPEs at under 2 bucks each for the woofers:

http://www.erseaudio.com/Products/NonPolarElectrolytic6DF/ANP10C-05-150-0-PB

Kent

[xmas111]

Hi Kent,

Thank you for the info. I'll definitely go that route. I'm trying to save $$$ like everyone else.

John

[dick]

John...Jeez, checked the backs of my 3a's and they're just like yours: plywood. So I stand corrected. As for coils, I t hnk I left the originals in place.

Kent: Nice info on 3a cap options. I followed CSP advice "way back when" and have, I think, Daytons in mine -- probably 2 years old now and much used. Wonder if/when I might change to others if it is advantageous. Any comments on that?

Dick

PS: after a few years of accidentally getting into this line of aural enhancement, the situation here is: a pair of AR3a's (house), a pair of AR4x's (Advent speakers) -- (bedroom), a pair of KLH 17's (greenhouse), 2 pairs of KLH23's (studio/workshop) which I run all at once.

[danajohnhill]

I like how you put your 3a restoration guide in a binder. Why didn't I think of that?

[xmas111]

I like how you put your 3a restoration guide in a binder. Why didn't I think of that?

Good Eye!

[xmas111]

Thanks to Kent I save about 1/2 the cost for the components.

Bought the following from ERSE. Great place, placed my order at lunch today and it shipped 4 hours later!

They didn't have the 6µF caps in stock so I bought four 3µF caps. 2 in parallel for each speaker. And bought an extra 100µF for the hell of it....cheap enough.

EAC33-18-1000......................2.............1.0mH 18ga EQ -Perfect Lay High Bond Air Core Inductor..................$7.17........$14.34

ANP10C-05-150.0/PB ........... 3.............150.0µF - 100v - 6% D.F. Non- Polarized Electrolytic Capacitors ....... $1.89........$5.67

51µF 250Vdc PulseX Cap ..... 2.............51.0μF 250v PulseX - Metall ized Polypropylene Film Capacitor ........ $11.71......$23.42

3µF 400Vdc PµlseX Cap ....... 4.............3.00μF 400v PulseX - Metalli zed Polypropylene Film Capacitor ........ $2.38........$9.52

Subtotal..........$52.95

Shipping.........$11.60

Tax..................0.00

Total..............$64.55

Thanks again Kent for the heads up.

Another quick question, should I leave the old 150/50µF cap in the cabinet. Not sure if removing could create any problems. It's quite large and would change the volume of empty space in the cabinet.

John

[xmas111]

Hate to keep bothering you guys.....but I assume I shouldn't try to remove the masonite board with the crossover components on.

There's a million staples holding it in place plus it looks like there's some type of glue aslo holding it.

I'm guessing it will break into several pieces and won't be able to be put back. And I'm also guessing the Black circle on the back side of the masionite with the pots and the speaker connectors would be ruined too.

Not a lot of room in the cabinet the do the rewiring but I can do it.....just easier if it could be removed.

John

[JKent]

Hi John

Glad that Erse site worked out for you.

I WOULD remove the old caps.

I would NOT try to remove the Masonite (for the reasons you gave).

And remember when you mount the new inductor: Do NOT use ferrous screws. You can use SOLID brass, stainless steel or nylon tie-wraps.

Working inside the box, through the big woofer hole, is really not a problem. Here's a photo of a 3a crossover rebuilt by crossover expert RoyC.

Also attached is a photo of my 3a xo. This was a royal PITA because I was converting a pair of AR3s to 3a's, so the entire xo had to be built from scratch. It was cramped because I kept all of the components in a confined space (unlike Roy who spread his out a bit) AND because I was using Ohmite pots. They had to be placed inside the project box because they are not sealed. Believe me; L-pads are a much better choice!

Good luck and keep us posted on your progress.

Kent

[xmas111]

Thanks again for the advice Kent.

I'm also going to replace the "nichrome wire". The schematic states it's 0.51 ohm 20 watts. Plan on using two 1.0 ohm 10 watts in parallel. Should they be non-inductive type?

I'll post some pics of the crossovers how they look now when I get home tonight.

John

[JKent]

Hi John

As you can see in the photo, I used two 1 ohm resistors in parallel, but that's only because I was building a new xo and did not have the nichrome. Don't know if replacement is necessary. I used plain ol' resistors that were lying around but non-inductive couldn't hurt. I like these Mills

http://www.parts-exp...artnumber=005-1

but they're expensive. They do come in 0.5 ohm. Don't know if 12 watts is enough. Maybe John O'Hanlon or Roy can advise on that. I'll send them a PM.

These Mundorfs are nice

http://www.madisound...film-resistors/

I followed your AR XA link. I have one in a box awaiting restoration. Bought it new in 1969, loaned it to a friend's teenage daughter in the 80s, got it back a few years ago. I may have some questions for you when I get started.

Kent

EDIT: OK, just heard back from the 2 experts and both said the Nichrome is an excellent non-inductive resistor that does not wear out, so leave it alone. IF you have cut it by mistake, then use 2 plain ol' 1 ohm 10 watt resistors in parallel as I did. Here are PE's "audio grade" resistors

http://www.parts-exp...artnumber=004-1

Hope this helps.

[xmas111]

Hi Kent,

Thank you again for the great info! I'll try to leave the nichrome wire intact.....hopefully I don't mess it up.

Below is a pic of one of the crossovers. The guy I bought them from said he replaced the pots. Well you can see from the pic he did but didn't put any covering over them and a few of the wires are sretched over the pots....not good.

I think I'll go with your idea of putting a small project box over them. I assume heat from the pots won't be an issue being enclosed.

I don't claim to be an expert in AR XA TT repair but I'll be more than happy to help if you need it. It's the least I owe you!

John

[JKent]

Well, the good news is those Ohmite pots are extremely high quality and very rugged so they will last forever. The bad news is the backs are open and they can get clogged with fiberglass. You can read about the various things people have tried. I like the plastic project box with aluminum cover. I doubt that heat is an issue but did drill a 1" hole in the side, covered with screening. There's a thread here about covering Ohmite pots. Just don't go too small on the box. Mine were a bit tight to work on. OTOH don't go too big or you risk changing the volume of the cabinet.

Like Goldilocks, you want it juuuuust right I used one like this: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=320-420

There's a close-up of the pots mounted inside the box in this thread: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=6266&st=0

This box may give more wiggle room http://www.parts-express.com/pe/showdetl.cfm?Partnumber=320-430

Here's one thread: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=5526&st=0 Adventagious made some very nice aluminum boxes but that takes skkill.

Kent

[xmas111]

One other thought I have is to replace the knurled nuts on the back with banana plugs. Has anyone tried it? Causes any problems?

Those knurled nuts are a pain in the butt, I've always disliked that type of speaker connector.

Of course you lose the original look.....but who see

John

[michiganpat]

I'd leave the original binding posts alone, and just use ring or spade terminals on the end of your speaker wire. if you like bananna connectors for swapping, just make short pigtails with ring or spades on one end, and a female bananna on the other.

as far as covering the pots, what's the diameter of them? if it's less than like 1 1/4" or so, get a 6 pack of dannon yogurt, eat the yogurt, and use 2 of the cups with some hot glue to cover the pots.

I suppose you could do the same with some 1 1/2" PVC, and just cover the open end with some open weave fabric and a rubber band or nylon zip tie.

[xmas111]

Good idea with the banana plugs on pigtails.

Bad idea with dannon yogurt.......I hate yogurt!

Actually it's not a bad idea. Thanks,

John

[JKent]

I agree with Pat on the pigtails. the connection to the terminals on the AR3a etc works very well if you put ring crimp-ons like these http://www.parts-express.com/pe/showdetl.cfm?Partnumber=095-212 on your speaker wire, but if you want the advantage of plugging in bananas, the pigtails work great.

If you use super-thick speaker wire you might want to go with these: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=095-675

If you decide to go with just binding posts, here's what CSP member Carl wrote:

For binding posts, this is what I would recommend and have used in the past on AR's, Advents, etc...

http://www.madisound...ing-post-black/

[xmas111]

Just want to share with you guys the progress I've made so far with the AR-3a's.

Im working on one speaker at a time.....

The first cabinet has been refinished. Sanded with obital sander. Cleaned with dry rag.

Filled the chipped corners with wood filler then colored with a brown magic marker.

Used Howards Restore-a-Finish then Feed-N-Wax.

Overall I'm pretty happy with the out come. But I was surprised how light the front trim came out compared to the rest of the cabinet.

Here's a few pics showing the before and after. Top, side and bottom.

John

[xmas111]

The crossover has been rebuild.

I put all the components on a piece of wood then wired them all up. Found it much easier than trying to do it all in the cabinet.

Put a small piece of masonite in the cabinet with two holes for the detents on the pots.

Built a box out of masonite to cover the pots.

The piece of wood and the box are almost the same volume as the big 150, 50mf cap I took out.

Now just need to get some sealer and put the speakers back in and see how it sounds.

If everything sounds ok, I'll start to rebuild the other speaker.

Here's a few pics of the crossover, box and after installing in the cabinet.

John