Martin

To help you identify, you may find the EIA code somewhere on the driver. It may be inside, where the driver meets the horn. The mark looks a little like the one Quad use, pictured below, but this is clearly not a Quad product.

Je pense que tu le feras trouve que la bobine mobile (how do you say voice coil in French?) est tiree.

FYI, in the early '70s, I used a Grado FCR (I think) as a spare cart with the AR XA & it sounded teriffic with no hum & no problems. Its relatively lower compliance made for an excellent paring with the XA tonearm.

I second Mike's recommendation, above, to use Quad. I have been using a Quad 405/33 with a pair of AR 3a and they go very well together.

Very interesting. These were not originally sold in USA and were not a part of Dynaco's US offerings. It looks kind of like a super-3-way A50.

Nice work, CYNR. Back to your original question, since 1970, I have been using oridinary Scott's Liquid Gold products on all of my wood speaker cabinets with great results. These products smell better than they did 50 years ago, but still provide a great way to top-off both oiled walnut & other oiled-wood finishes to keep them looking nice. I've even used SLG as a final (and, only) finish on newly-sanded oiled walnut with beautiful results. I learned to use the product from my mother, a non-audiophile, who used it to keep the wood floors in good condition.

In answer to your message/question to me, to clarify, early on in this discussion, both Frankmarsi & JKent suggested the safe solution of using 2 power amps, one for each speaker pair. JKent went a step further & essentially solved your problem by pointing out that your PAT-4 has two pairs of power amp outputs, unlike most other preamps, which don't. You'd just need to get another ST-120 so that you can use one ST-120 for each pair of 2aXs. This solves your problem very elegantly, leaving you with everything being well-matched. The "problem" that is being solved here is actually worse than it appears and I alluded to it early on: 2aX impedance does drop to approx 4 ohms (see CR speaker article, May '70). Thus, using two in parallel could result in a 2-ohm load, something that your ST-120 won't like. The ST-120 likes an 8-ohm load and should be comfortable with one pair of 2aX despite the variation in 2aX's impedance. I hope this is a clearer explanation.

Your University speakers are a nice find. Highly efficient and therefore, the opposite in so many ways of the New England speakers we love. I have a lone University 6303 which is a cheap version of yours and it sounds fantastic. BTW, I like JKent's idea to use 2 stereo amps to power your stacked 2aXs. That solves the impedance problem nicely.

I'd advise caution as Larybody suggests. Neither the 2aX nor Advent has a particularly flat impedence curve, unlike the Dynaco A25, which does, relatively speaking.

Thanks for the correction! It certainly sounded & tracked more like a ceramic pickup than a magnetic one. My basis for in-home comparison was an AR XA with M91E connected to the AR receiver & Dyna A25s, granted, an unfair matchup.

Norman's suggestions are spot-on; my opinion of the KLH Model 20 is even a bit less charitable. The amplifier section is barely adequate, the turntable, even less so. The tonearm & ceramic pickup are way below adequate. This is just my 2cents based on very brief ownership; I couldn't wait to get rid of it.

Thanks for this post. This loudspeaker was way ahead of its time in so many ways. It should have been a bigger sales success, but the loudspeaker market has always been a tough one.

I have owned multiple pairs of XI & XIa & XIb in the past and I agree, the XI line were surprisingly high quality speaker systems, very competive with KLH 17 & AR 4x. The original cone tweeters were fine and perfectly adequate, but truly, they were nothing special and IMO, the Philips replacements you already have are superior to what was in there originally. They are also superior to the common, modern, cheap, paper cone tweeters available now. Rectilinear used several different tweeters, including the phenolic type, in the XI, XIa & XIb. Most of them used a simple, black paper cone, not the phenolic--I can't remember which model used which tweeter. Your Philips are a very versatile tweeter that was widely used in many 2- and 3-way speakers from the early 1970s, most of which were rather higher-end than the XIa & b. I can recall several models from B&O, Avid, Philips & others that used the 0160 to good effect. They were also popular as a DIY tweeter for speaker builders and that is how I became familiar with them at first. I remember buying a new pair of them for around $25 in the mid-'70s. Their ability to reproduce & handle 2000 Hz should equal the capability of the originals, so non ti preoccupare! There is no problem. Do you have XIa or XIb? I'm not sure that your pictures match your comments about which model you have. Keep in mind that Rectiliinear's crossover point supposedly did vary from 1000 Hz to 2000 Hz, depending upon the specific XI model. So 1000 Hz is probably a bit low for the 0160, 1800 or 2000 Hz is of no concern at all, but in the end, my past experience tells me it doesn't matter as it is a fairly heavy-duty unit. So, if you're not too concerned about preserving originality and care only about how good they sound, I think you can leave them in place. Your tweeter level control will allow you to adjust them to your liking. If you insist on changing the tweeters, I think several of us can help you pick a replacement.

You might think twice before replacing your Philips tweeter. It's a better-sounding unit than the Peerless it replaced. You have a tweeter level control which should enable you to tone it down if need be. The original Peerless units are not hard to find as they were used in many different speaker systems from different brands. Many Rectilinear models used them, but many are severely mangled because of the tenacious adhesive that Rectilinear used to install them.

The Peerless super tweeters are not that hard to find; they were used in a lot of different '70s speaker systems. Many of them are discarded because they are very difficult to remove without bending the metal frames and destroying them. Don't ask me how I know. Finding a similar, modern replacement tweeter should also be relatively easy. The dark-colored Rectilinear fabrics are difficult to match, but you can come pretty close at a good fabric store.

Joe, The summary Kent provided is right on target. I can verify from recent, personal experience, having just restored the pots in my 3a's in just a few hours at zero cost by cleaning them. At the same time, I also replaced the caps for just a few dollars using inexpensive caps from PE & Erse. The day after I finished, a friend came by, heard them & even though they are not for sale, offered $1500, which I politely declined. They are too good to sell. The quality of guidance available here to help you do the job yourself is unparalleled. Take up the offer if you can.

I'm about to restore my AR-3as and would love to keep things original, except for caps, of course. I get the vibe that the vinegar & salt bath is not viewed too favorably. I've used that method on 2aX, 4X, 5, etc. & always had good results except when the solution consumed an already degraded wiper. Any chemists out there?

In the past, I have always used the chemical method described in the other audio website that suggests using a vinegar & salt solution to clean the copper pads inside the ceramic pots. It has always worked very well for me and produces nice, shiny, conductive, copper surfaces. I don't think I have ever had to use a physical method, like polishing with a Dremel, after using that particular chemical treatment. It is very easy & effective. It is, however, somewhat caustic, and is very rough on, for example, wipers that are past their prime, so it probably shouldn't be used on wipers. I've read about using Brasso (which is both chemical & then physical when you wipe it off), a polishing wheel on a Dremel, & fine abrasive paper. What cleaning methods are your favorites?

You will find that removing the tweeter & midrange are much harder than it appears. Don't ask me how I know....

This "A45" was not sold in the US and was likely a European Scan product, of which there were several.

Pete, I have also seen "reports" of an A40, but those reports are not correct in that no A40 model was ever sold in the US. There was no A35XL, but there was an A40XL which was, more or less, an A25XL in a larger enclosure that was very similar to the A35 enclosure.

Great photo. I've never seen them all together in one picture before.

Well, I'm surprised you're surprised that I like the EPIs so much. Since their introduction, I always felt they gave the A25 a good, solid challenge. Over the years, I've owned two pairs, I think, as well as one bigger pair that had the equivalent of two 100s in each cabinet. All were first-rate, satisfying speakers. I will reread those old, priceless (some would say, "clueless"), CR 1970s speaker articles to refresh my memory.

Yes, the A-25 VW was a great one and was untouchable at its original low price. Looks like you are ready to set up a stacked pair.

Thanks, Rick. It may look the same as an A25 woofer, but it's actually 15 ohm, rather than 8, so it's not common. As of this afternoon, I think I have identified the problem: loose, rattling terminals which I can fix.