AR-XB. Is it worth a new motor?

New motor definitely! The stock AR-XB is a formidable TT that can compete with others in the four-figure price range. I have one modded by Vinyl Nirvana with a Technics tone arm tube and headshell replacing the stock arm tube and damping applied inside the refinished plinth and platter. 

If the motor is humming, and the motor shaft spins freely then it's likely the phase-shift capacitor/resistor assembly in need of replacement, and not the motor itself.  This is an AC synchronous motor, with the simplest of control circuitry.  I'd guess around $5 in parts and a bit of soldering.  

No it is not. In it's day the AR XA was a revelation. It blew away all those idler drive tables with it's suspension and belt drive. It's only major failing was a tonearm without an anti skate mechanism. In the day when Edgar Villchur designed it most arms did not have an anti skate mechanism. With todays cartridges an anti skate mechanism is mandatory. The XB did not remedy the problem and by then cartridges like the Shure V15 came along which could be ruined by that arm. It is extremely difficult to change arms on that table because the mass of the arm has to be identical or the suspension will not work properly. I'm sorry to report this, I'm afraid you got screwed. If $200 is the most you get stung for in this life you are incredibly lucky. 

I was gonna say, it might not be the motor, something else.

just hopping about, found this parts listing (no motor)

I would not use an arm with no anti-skate as mentioned above.

What Palasr said. Replace that capacitor. There’s probably enough friction at the pivot to provide some natural anti-skate. 

lewm,

IMO, this time you are giving bad advice.

I forget where, but I have read a few places:

The MAJORITY of stylus’s are WORN on ONE EDGE ONLY.

That is from poorly set ANTI-SKATE.

Thus, the MAJORITY of people’s TTs have anti-skate set IMPROPERLY.

Relying on some friction from the bearing is no way accurate. All tonearms I have messed with for over 50 years definitely skate in with anti-skate set to zero. ALL

Let’s not forget, the modern advanced stylus many of us use need to be precisely aligned for their potential performance and avoiding both groove wear (damage) and stylus wear, a progressively important actor for expensive MC cartridges.

You do not get the extended life of an advanced stylus unless everything is proper:

anti-skate zero until it is the last step: overhang, two null points, azimuth and VTA and tracking force, last: anti-skate. Check tracking weight and anti-skate every few months.

No dust cover: you gotta be kidding me.

I highly recommend using the blank side of an alignment LP, and simply see skate and set anti-skate force visually

Oh Yeah: sometimes we are hesitant to fully tighten the two screws holding the cartridge. Double check overhang/null points after a few months, moved a speck? or where you put it?

Dear Elliot, Your last post is full of holes. First you say, in caps, that the majority of styli are worn on one edge only. Doesn’t that suggest that "the majority" of us have been using either too much or too little AS? So, if the AR-XB tonearm does have some above average friction at the pivot in the horizontal plane (which is quite likely due to its age alone), then that amount of friction is either too much or too little in terms of AS. This puts the user in the same boat with the rest of us, neither better off nor worse off.

You also suggest that there is a "proper" amount of AS. Perhaps there is, but most of us don’t find that magic amount, if the "majority" of styli are assymetrically worn. Further, have you ever seen a graphic representation of the magnitude of the skating force, as the stylus traverses across the surface of an average LP? So, imagine or search for that graph, with magnitude on the Y-axis and distance from the spindle on the X-axis. It describes an inverted parabola, if memory serves. Whereas we artificially apply a skating force that is constant across the surface of the LP; in other words, a straight line on that same graph. A straight line can only intersect a parabola at two points. This means that no matter what we do, the AS can only be "correct" at two instances during the course of playing an average LP, no matter what method one uses to select the amount of AS. And this leaves out the major effect of groove tortuosity on variations in the skating force.

You seem to espouse the method for setting AS that involves playing a groove-less LP and watching what the tonearm does at various AS settings. I realize this is a bone of contention among anal audiophiles, but it is my opinion that, because the skating force arises due to friction of the stylus tip in the groove, note "in the groove", and because groove tortuosity has much to do with the constant variability of the skating force, you’re kidding yourself if you think you can arrive at a "correct" setting for AS using a blank LP. I realize there are some gurus who disagree with me on that subject.

So, in the final analysis, I think relying upon friction at the pivot to supply some AS is not so crazy. Further, I would also posit that much of aberrant stylus wear that is observed apparently by re-tippers is due to our playing too much with azimuth while trying to arrive at equal crosstalk using a Fozgometer or some other similar gadget. I am a big proponent of setting azimuth so the stylus sits squarely in the groove, regardless of electronic measurement. The enemy is us, when it comes to uneven stylus wear.

Google AR-XB motor repair.

Some good YouTube vid's on disassembly/repair.

I would start by replacing the start and runs caps, (for a few bucks/covered in some of the vid's) before disassembling the motor - to see if that is the main problem.

DeKay

Thank you all for the responses! Some really good info and education. Here's my take away: keep the table, which other than the motor, is in great shape, check out the capacitors as the motor does turn freely, and if that doesn't work then try and rebuild the motor (I did watch the video) or replace the motor and maybe down the road, replace the arm and headshell as I understand there are some Technics(?) arms that will work with this table. Did I get that right?

This has the similarity of having a boat. A hole in the water you throw money at. Even though I know nothing about this TT,  my advice is to move on and be glad all you threw at it is 200 bucks.

Parted out you should recover your cost with a good frame (revolutionary design), arm, bearings, plinth and platter. BUT the AR-XB is a fine piece of audio history and worth saving or passing on. Acoustic Research was a benchmark company. Here's a news flash, history doesn't start the day a person is born and everything was not made to throw away.... Americans, jeez. I am guessing that the lube in the motor has hardened, and the start capacitor is way past its use by date and you don't need a motor (I like the hum, it's trying). The AR was designed for a conical stylus (the, supposed anti-skate issue), and there are some great MM's, and even a couple MC's available (Denon). Most people set the anti-skate too high, I did until I got a test record. I have a Thorens TD 165 that's happiest with minimum anti-skate. Now that I'm aware I think I'd like to get the O-scope repaired. I was told it was an easy fix, but that was ten years ago.... hmmm maybe chineseium?  I like your Sony backup TT, and will just mention U-Turn Turntables from Massachusetts (born and made in USA by entrepreneurs), I think almost, if not all the TT's in the line are upgraded with the magnesium arm, and the new belt and platter from the Orbit Theory (I'm a proud owner, punches way above its price (hosting my Sure V15 IV but needed VTA spacer), but I know, not made in a foreign country, sorry). If you need a line input for a second TT Orbit has you covered there, too. Good luck, and please don't just toss the AR   :)

The XB retailed for $130 in 1972. 

I just picked one (77XB) up recently with a similar symptom as yours.  On mine, giving the platter a manual spin to help it reach 33.33 rpm works.  I did replace the cap, but it made no difference.  A full motor rebuild is in the future.  For now, I put an M91ED body and got a NSS elliptical N91ED from LP Gear.  It sounds glorious after some lube of the bearings (arm and platter) adjustment of the suspension, and dialing in the cartridge alignment.  Mijostyn is very knowledgeable but I differ on this point…much stylus wear comes from insufficient tracking force to maintain groove wall contact in the misguided pursuit of low VTF. Using the upper end of the recommended range is the simple solution for most non-SOTA arms used by most people.  I realize some A-Goners do have SOTA rigs with superb precision arms, but that was Villchur’s view and I haven’t seen it disproven.  No one is comparing an XA or XB to gigabuck tonearms, it was meant to be affordable high fidelity and in that context is one of the greatest inventions of its time.

Thanks to all who have responded. Everything helps. It seems like folks are hesitant about the Ortofon on this table. Reasons?

@baylinor I own a JD tractor that is worth more now than when I bought it 5 years ago. Past price is not always an indication of future worth.

@puptent @jasonbourne71 I have no intention of selling it. I’ve wanted an AR since my college days in the 70’s. I’ve been in contact with Dave at Vinyl Nirvana (what a nice guy!) and just looking at that site is encouraging.

@palasr I’m not good with a soldering iron. Ask me to wire a house? No problem...big wires and big tools. I do have a local tech who does fine work that will soon see this table.

Again, thanks to all who have responded (and, hopefully, will continue). I’ll post pics when it’s running again.

Chuck

I have been sitting on the fence on this thread.  I used to have a C26 and a 2100 and can't let you dangle in the breeze.  The AR turntable is an enigma.  It was a brilliant, though flawed design.  With the 3 point suspension it was copied first by Thorens and then by some charlatan in Scotland ;-) who certainly validated the concept.  But the arm, OMG the arm was a disaster.  It chewed up stylii like they were candy.  It had waaay too much friction you see.  There is nothing for it frankly.  The AR turntable is for suckers.  Fix it if you can and sell it to one of those and may G*d have mercy on your soul.  Go in peace. 

@billstevenson Thanks for getting off the fence, the feedback is much appreciated. I have been going back and forth between charging ahead and restoring the table to like new condition or putting it on the back shelf while I do some research about arm/headshell replacement vs buying a used, more modern table. So, I am on the fence as well. Especially after having a talk with my tech about how people started modding the table almost as soon as it was put on the market. Either way, I will keep the table as it is a "fine piece of audio history".