AR-LST's For sale

[Guest dogmeninreno]

I have a near mint set of AR-LST's for sale. dald@sbcglobal.net

Oiled walnut in excellent condition with original drivers. Dale in Reno.....Will negociate for a pair of AR9's

[tysontom]

Are these "for-sale" LST's front-wired ("hard-wired") or back-wired vesions? What is the serial-number range?

Thanks,

--Tom Tyson

[Guest dogmeninreno]

Tom, These are front wired SN 01451 10/73 and 01647 10/73 Pressboard back and plywood driver mounting plate. Access to the xovers is thtu the front. I had a pair that the xovers came out from the back. Dale

[Guest]

Tom,

What's the difference of the front vs. rear wired LST's? BTW, why were they wired on the front and covered with electrical tape? It is'nt the prettiest thing in the audio world Mine are front wired with serial #'s 367/ 369.

[tysontom]

>Tom,

>What's the difference of the front vs. rear wired LST's?

>BTW, why were they wired on the front and covered with

>electrical tape? It is'nt the prettiest thing in the audio

>world Mine are front wired with serial #'s 367/ 369.

The "hard-wired" tweeters and midranges date back to the first 1958 AR-3, in which the tweeter leads were taken from the voice coil out over the top plate (the tape was put under and above the original aluminum wire) and soldered to the "tweeter terminal strip." The terminal strip was wired internally to the crossover. This process worked well into the 60s and 70s, with all the AR speakers being made this way. The original raised terminal evolved into a flush-mounted terminal strip, and the tweeter lead wires were by this time, of course, copper instead of the AR-3's very light-weight, but fragile aluminum wire.

This process worked fine because in those halcion days of audio, the front grill panels, with the exception of the AR-LST, did not "pop" off with velcro or fasteners, but were glued on. Looks were not a real consideration other than to blacken out the front panel under the grill.

The black electrical tape was a way to protect the bare leadwire from the tweeters from shorting or abrading against the top plate which, in the original AR-3's was made of blued steel. Tape was put on top of the plate, the wire place on top of it, then another layer of tape was put to hold the wire in place. This same practice was used on the LST as well.

In 1974, with the introduction of AR's Advanced Development Division speakers, such as the AR-10Pi, AR-11, etc., AR began putting tabs on the back of each tweeter and midrange, and connecting the crossover wires with push-on solderless (tabs) connectors. This practice worked its way over into AR-3a's and a redesigned AR-LST, with the hard-wired drivers being updated with the back-wired versions. No other wiring or crossover changes of note were made at that time.

Incidentally, the LST serial numbers 367 and 369 were early ones, probably dating back to 1972, I think.

--Tom Tyson

[Guest SteveG]

Tom, Dale, and bhans,

My LSTs are labeled as LO1243 and LO1244, and both say below this number "EIA 561 73 42". I am guessing that the 73 in the latter number indicated year of manufacture but not sure about the rest. The back label also says Teledyne, so I had earlier assumed that perhaps these were manufactured later than 1973. I bought them used in early 1978. However, I just looked at the repair receipt from fact authorized service center that replaced a bad midrange that was bad when I bought these. I hadn't noticed befire that the service center wrote in 10/29/73 for the purchase date. I don't know where they got this from as I did not know manufacture date or orig purchase date. I assume they got it from AR records?? Does that sound right??

While I have you I am hoping you might address another Q I raised in another thread. As the input terminals on back are only 1 and 2, these are not subject to "vertical biamplification" I assume. I am running these with a single Adcom 555 rated at 325 watts/chanel at 4 ohms. Would you think there is any advantage with these to use two power amps of this type bridged?? Seems like 325 watts are plenty, so would there be a real advantage to more? And further, are the charistics of this amp changed if bridge so that it becomes noisier or less stable at low impedence??? Would this be a good or bad idea?? I play these pretty loud in a large fairly dead room, but not at rock concert levels. Also, any thoughts onwhether an Adcom 5500, 5800, or 5802 with mosfet design would provide any "audible" difference from the older 555 design??

Thanks much

Steve

[Guest SteveG]

Hi all, I found some discussion on bridging amps for low impedance loads on a site on other speakers that also have nominal impedance of 4 ohms. See Q/A under Chris Frie in the link below.

http://www.audiocircuit.com/9041-esl-circu...-QUE-AS-2-4.htm

Assuming this is right that the bridged-amp sees essentially half the speaker's normal impedance, then it seems that bridging with LSTs and most AR speakers would not be a great idea, even with the Adscoms that seem to have a reputation for being very good at low impedance. Does this sound right???

Thanks Steve

[Guest]

Tom,

"This practice worked its way over into AR-3a's and a redesigned AR-LST, with the hard-wired drivers being updated with the back-wired versions. No other wiring or crossover changes of note were made at that time."

Any thoughts on how each version of the LST compare? The reason I ask is my pair of LST (slowly being rebuilt) has one of each.

Thanks,

Shawn

[tysontom]

>Tom, Dale, and bhans,

>

>My LSTs are labeled as LO1243 and LO1244, and both say below

>this number "EIA 561 73 42". I am guessing that the 73 in

>the latter number indicated year of manufacture but not sure

>about the rest. The back label also says Teledyne, so I had

>earlier assumed that perhaps these were manufactured later

>than 1973. I bought them used in early 1978. However, I

>just looked at the repair receipt from fact authorized

>service center that replaced a bad midrange that was bad

>when I bought these. I hadn't noticed befire that the

>service center wrote in 10/29/73 for the purchase date. I

>don't know where they got this from as I did not know

>manufacture date or orig purchase date. I assume they got

>it from AR records?? Does that sound right??

1973 sounds about right for serial numbers in that range. The Teledyne thing is immaterial, as they came on the scene in 1967 when they purchased AR from (primarily) Ed Villchur and some other stockholders of note. Incidentally, the designer of the AR-LST, Roy Allison, stayed on at AR for five years (as did other officers of the company) after Teledyne purchased the company in 1967, part of the original agreement. Therefore, Roy left in 1972, and began to pursue the room-boundary effect and later the founding of Allison Acoustics.

>

>While I have you I am hoping you might address another Q I

>raised in another thread. As the input terminals on back

>are only 1 and 2, these are not subject to "vertical

>biamplification" I assume. I am running these with a single

>Adcom 555 rated at 325 watts/chanel at 4 ohms. Would you

>think there is any advantage with these to use two power

>amps of this type bridged?? Seems like 325 watts are

>plenty, so would there be a real advantage to more? And

>further, are the charistics of this amp changed if bridge so

>that it becomes noisier or less stable at low impedence???

>Would this be a good or bad idea?? I play these pretty loud

>in a large fairly dead room, but not at rock concert levels.

> Also, any thoughts onwhether an Adcom 5500, 5800, or 5802

>with mosfet design would provide any "audible" difference

>from the older 555 design??

Bi-amping the LST cannot be done without ripping into the crossover and changing things around drastically. I don't know of anyone who has done it. But more importantly, there is probably no real advantage in doing it, because with the auto transformer the output of woofer, midrange and tweeter sections are pretty closely matched. Since the speaker has very, very low distortion to begin with, bi-amping is probably unnecessary.

As for the Adcom amps, any of those models mentioned should be adequate to drive the LST under most circumstances. Adcom amps are all capable of close to 3-dB headroom peaks, so you should have plenty of power without clipping. If you can find an Adcom GFA-5800 or GFA-5802, or a pair or mono GFA-565 amps, you can't go wrong. Any of these can put 500-600-watt peaks into 4 ohms without problem, and that would be a very high SPL level. However, be certain to run the recommended fuse -- or better yet -- drop down a size in the Buss FNM range to 1-1/2 amp slow-blow rather than the standard 2-amp slow blow. As stuff gets older, it gets a bit more fragile, so why not put in an extra measure of protection. Although it is tempting to play the LSTs at very high levels, resist this temptation, because if you were to inadvertantly clip one of those amplifiers, you could burn out as many as eight original-style tweeters, and they are essentially "no more." You would have to replace the tweeters with the newer style version, and the sound characteristics of the speaker will change (possibly better or worse).

--Tom Tyson

[tysontom]

>Tom,

>

>Any thoughts on how each version of the LST compare? The

>reason I ask is my pair of LST (slowly being rebuilt) has

>one of each.

As far as I know there is virtually no difference in the sound quality in the entire range of AR-LSTs manufactured. A capacitor value was changed in the crossover at one point (and I think this was before the back-wired version was introduced), but the actual sound characteristics remained unchanged as far as I can tell. With properly functioning AR-LSTs of different vintages, I seriously doubt that you could tell the difference if blindfolded, so I wouldn't worry about it. The grill-cloth material did, however, change after about 1974 or so to the new, thicker, whiter linen. The original beige-linen cloth -- the most desirable -- became unavailable and a newer, whiter linen was used. It was a bit more opaque and possibly muffled the sound a fraction more than the original linen, but the difference would be slight at best.

--Tom Tyson

[Guest SteveG]

Tom, Thanks for idea about the fuses. I have the originals still installed and agree that an extra measure of protection is a great idea. In addition to a slow blow fuse, would it make any sense to add a fast blow fuse of, I assume, a higher rating, to protect against a dangerous spike?? Or would normal transients in regular music just set these off all the time? If this were a good idea where would you install them?

Thanks also for idea in Adcom 5800, 5802, or 565's. I assume by this recommendation you would NOT recommend bridging a pair of 555's. Is that right?

Thanks

SteveG

[Guest dogmeninreno]

Tom, Did you receive my NOS grill fabric? Thanks, Dale in Reno, Nv.....

[tysontom]

>Tom, Thanks for idea about the fuses. I have the originals

>still installed and agree that an extra measure of

>protection is a great idea. In addition to a slow blow

>fuse, would it make any sense to add a fast blow fuse of, I

>assume, a higher rating, to protect against a dangerous

>spike?? Or would normal transients in regular music just

>set these off all the time? If this were a good idea where

>would you install them?

It would not help to have two fuses in the system; and in any event,

the problem with fast-blow fuses is that, in order to keep from blowing all the time, the amperage rating would have to be quite high -- perhaps four or five amps or more. With a slow-blow fuse (categorically the Bussman FNM-Series only, do not use the small glass slow-blow fuses), the speaker can accept relatively large peaks without thermal stress, yet if high-average input power is sustained, the fuse will let go. It is similar to a motor-start fuse, allowing a large "in-rush" of current before leveling off to a steady-state rating.

However, don't be fooled into thinking that fuses will always save the speakers: they will only protect agaist the types of things you would see in music with large peaks but relatively low average power. Sinewave-testing will always burn out a tweeter voice coil long before taking out a fuse -- guaranteed.

>

>Thanks also for idea in Adcom 5800, 5802, or 565's. I

>assume by this recommendation you would NOT recommend

>bridging a pair of 555's. Is that right?

>

I have not had much experience bridging amplifiers, but I have never been comfortable with it. The impedance rating does go up by double the amount, I do know, so the amplifier would have a nominal impedance rating of eight ohms in bridge mode if normally the amp is rated for a nominal four-ohm rating. It will probably run very hot trying to drive the less-than-four-ohm load of an AR-LST (which is less than 3 ohms at certain frequencies in certain switch combinations). Remember, too, that the LST is a very difficult load for most amplifiers anyway with its low-impedance, low-sensitivity, capacitive-reactance load. This is a nightmare for many amplifiers even at normal-volume settings; when the power goes up, things can get serious for an amplifier not up to the task. I know this from personal experience, having destroyed two separate stereo amplifiers before finally settling on a MacIntosh MC2500, which never flinched. Another superb amplifier, though expensive like the Mac, is the Crown Macro-Reference (semi-professional) or the current version, Studio-Reference amplifier.

--Tom Tyson

[tysontom]

>Tom, Did you receive my NOS grill fabric? Thanks, Dale in

>Reno, Nv.....

Hi, Dale,

Yes, I received the samples today. Very interesting!!! I can't figure out who made this grill, as it is very slightly different from the original beige linen. It is, nevertheless, very close, and seems to be high quality. It clearly is open-enough for good performance, something the mid-70's replacement-grill material didn't seem to do so well.

Thanks for sending it. I am going to compare it very closely to the original stuff (I still have a little of it left). How much of it do you have? Do you have the raw cloth, or do you have it stapled on the grill panels?

Thanks again,

--Tom Tyson

[Guest dogmeninreno]

Hi Tom, I have 600+ yards of the off white that I sent you, 390 yards of the off off white and 360 yards of the white. All of this is on rolls that measure 59" wide not precut. A lot of buyers seem to prefer the white because I guess they dye it with tea, coffee or other stuff to get their desired shades. The fabric is a product made overseas and is a real high quality linen. I bought this fabric at an auction in the bay area about year ago from a warehouse at a company who claimed to sub contract to AR and Advent to supply grills for the speakers. They had grill supports, badges and all sorts of stuff that I didn't win but it was interesting!

Thanks, Dale in Reno.....PS, Don't forget that I am looking for a pair of AR9's OK?

[charger3834]

Hi Dale and Tom

I need some cloth for my 1960s 2ax's. All the AR's I own have the same color cloth. It looks like a beige/off white. Which do you suggest.

Brad Evans

[Guest dogmeninreno]

Charger, Send me your ship to address and I will send you 3 shades of fabric. I prefer the off white myself. Some folks buy the white and use coffee or tea to get the desired shade. No charge. dald@sbcglobal.net

[Guest dogmeninreno]

FYI guys, These almost mint AR-LST's are going on auction tomorrow. I had no interest from this forum so here we go! Thanks anyway. Dale in Reno, Nv.....

To Tom, interesting comments on ported vs: sealed. I read it with interest. Tom, you are not related to John Tyson are you? He is quite a guy in Reno Nv.

[Guest dogmeninreno]

>FYI guys, These almost mint AR-LST's are going on auction

>tomorrow. I had no interest from this forum so here we go!

>Thanks anyway. Dale in Reno, Nv.....

>To Tom, interesting comments on ported vs: sealed. I read it

>with interest. Tom, you are not related to John Tyson are

>you? He is quite a guy in Reno Nv.

Well I didn't make the auction at the time I thought, but tomorrow I hope. Dale

[ToastedAlmond]

Dale,

I have a pilot buddy named Gerhard Augustus Leipfinger (is that a great moniker or what!!) He lives in the next town over from here. He has a pair of LST's with the front wiring. He is the original owner, and also had AR-5's (front wired) that he was using for rears. He doesn't have the 5's anymore because I bought them about 10 yrs ago. He has recently re-married. The new, and lovely Mrs. Leipfinger (half his age) is not exactly in love with his LST's. I am waiting those out. If nothing else I'll save on the shipping, and his are mint also. Re-foamed as of 1989, when he got carried away with Telarc's release of The 1812 Overture.

Hope you get a million for them. You are NOT getting MY 9's.

George

[Guest dogmeninreno]

George, Darn it. I thought you were getting soft and I might get the 9's. Oh well. Thanks, Dale

[charger3834]

"The new, and lovely Mrs. Leipfinger (half his age) is not exactly in love with his LST's."

Why is it that most women don't appreciate AR Speakers; they have sensitive hearing ??

[ToastedAlmond]

Charger,

Probably because they don't get the same decorating options as their good friends with Bose cubes. VERY powerful force the WAF is. When it comes to that kind of stuff, my wife, the former Theresa Talamonti, is an absolute saint.

I have the AR-9's in our family/HT room. To be honest, I could probably get away with putting ANOTHER pair in there as surrounds. She's THAT understanding. I have also commandeered a whole room to myself in another part of the house, strictly for my 2 channel stereo rig. I have no shortage of great, classic speaks that I could insert into the family room as surrounds. I can't bring myself to do it to her, so it's 2 channel home theater for me. Those 9's image so darn well, that once involved in a movie, nothing is missing.

George

[tysontom]

>>Tom,

>>What's the difference of the front vs. rear wired LST's?

>>BTW, why were they wired on the front and covered with

>>electrical tape? It is'nt the prettiest thing in the audio

>>world Mine are front wired with serial #'s 367/ 369.

>

>The "hard-wired" tweeters and midranges date back to the

>first 1958 AR-3, in which the tweeter leads were taken from

>the voice coil out over the top plate (the tape was put

>under and above the original aluminum wire) and soldered to

>the "tweeter terminal strip." The terminal strip was wired

>internally to the crossover. This process worked well into

>the 60s and 70s, with all the AR speakers being made this

>way. The original raised terminal evolved into a

>flush-mounted terminal strip, and the tweeter lead wires

>were by this time, of course, copper instead of the AR-3's

>very light-weight, but fragile aluminum wire.

>

>This process worked fine because in those halcion days of

>audio, the front grill panels, with the exception of the

>AR-LST, did not "pop" off with velcro or fasteners, but were

>glued on. Looks were not a real consideration other than to

>blacken out the front panel under the grill.

>

>The black electrical tape was a way to protect the bare

>leadwire from the tweeters from shorting or abrading against

>the top plate which, in the original AR-3's was made of

>blued steel. Tape was put on top of the plate, the wire

>place on top of it, then another layer of tape was put to

>hold the wire in place. This same practice was used on the

>LST as well.

>

>In 1974, with the introduction of AR's Advanced Development

>Division speakers, such as the AR-10Pi, AR-11, etc., AR

>began putting tabs on the back of each tweeter and midrange,

>and connecting the crossover wires with push-on solderless

>(tabs) connectors. This practice worked its way over into

>AR-3a's and a redesigned AR-LST, with the hard-wired drivers

>being updated with the back-wired versions. No other wiring

>or crossover changes of note were made at that time.

>

>Incidentally, the LST serial numbers 367 and 369 were early

>ones, probably dating back to 1972, I think.

>

>

>--Tom Tyson

I just noticed another mistake of my own doing. The AR Advanced Development Division, and with it the AR-10Pi, AR-11, and AR-MST, came about effective March 17, 1975, not "In 1974..." as I stated above. No big deal, but accuracy is important. I think the back-wired drivers arrived at that time also, or soon after supplies of the old hard-wired production drivers were exhausted.