Jump to content

AR LST road trip....


xmas111

Recommended Posts

  • Replies 88
  • Created
  • Last Reply

WOW!!! I'm sure if can't find something from flea bay someone here knows some good ppl which could recone for you.I'm wondering if that woofer voice coil former wasn't damaged before you got them?

Link to comment
Share on other sites

Kent,

Yup, it was the AR 3a restoration Guide that recommends the 1-2-3 Stitch Wichelt "lambswool" linen but you pushed me towards it.

Looks like I got the last of it too, 1-2-3 Stitch is out of stock at the moment.....good thing they had it in stock when I bought or I would of gone for something else and never realized how good Wichelt "lambswool" linen is!

As for the TT I have two that I have to restore and one of them is the same as yours with the top plate pretty messed up. Not sure how I'm going to handle it yet. But more than likely I'll end up sanding it or blast cleaning down to the bare metal and paint it. I sure you've seen some of the wonderful jobs others have done painting it.

Not looking forward to that job.... a painter I'm not!

Anyway, in my opinion I think it will be best to get the top plate down to bare metal then paint or whatever.

Having the RCA jacks on the back really make it easy to hook it up with some nice RCA cables.

I've seen some people put a grounding terminal on the back too but I don't think it's necessary since the ground wire on the RCA cables go to the same ground on the pre amp or receiver as the separate grounding wire would.

John

Hi there

A thought regarding the RCA connections.

The original AR cable capacitance up to and including the cartridge shell was 125 pf.

Some research will be required in buying the correct footage cable for a replacement.

Link to comment
Share on other sites

Well guys the fun is OVER!!!

I finally hooked up the LST's to one of my Carver TFM-45's and was listening to some tunes when all of a sudden I heard a pop!

Turns out one of the woofers is dead! I took it out and measured the resistance and got about 1 1/2 Ω. No movement of the cone either.

Excuse my langauge...but son of a bitch...I knew it was to good to be ture finally getting the things and hoping for years of enjoyment out of them.

I certainly wasn't cranking them...can't believe it happen!

Not sure what my next step will be. Send it out for repair or try and rebuild it myself????? I've never reconed a speaker before and I'm not even sure where you could get a cone for one of these.

Damn.....damn.....damn.....

John

I would try John at MSound,I'm sure he could help you out in some way.Also reconing is not that hard.I just did 3 AR 10" woofers with cone kits from John.They all came out good and I've never done a recone before.He has very good kits and good instructions.With all the great work you've done on these speakers I'm sure you would have no problem reconing.
Link to comment
Share on other sites

I'll try and give John a call at MSound.

Has anyone used any of these reconing kits?

http://www.simplyspe...econe-kits.html

I'm thinking maybe I should do both woofers just in case the other one was damaged prior to me buying them. Of course there's no way to know without taking it apart.

Also I'm guessing the screen mesh on the outside of the basket will need to be removed to do the repair.....

I've read a few posts on here about AB Tech Services, has anyone tried their replacement 12" AR woofers?

http://www.abtechservices.com/arspeakers.html

John

Link to comment
Share on other sites

John, I know you are searching out all the alternatives looking for the "best." I think original drivers are better than replacements if they can be rebuilt.

IMHO:

  • yes--do both
  • M_Sound has the best kits AND SERVICE so I would only buy his kits. If you do, tell him you are a CSP member.
  • Bill LeGall is a speaker GENIUS. You might consider sending the pair to him. If it is humanly possible to repair them, they will come back like new.

Just my $.02

Kent

Link to comment
Share on other sites

Thanks for the info guys.

M_sound is going to call me tomorrow so I can give him the proper imformation to get the right recone kits.

I didn't realize the AR 11" woofer has to different recone kits. Some had a 5.5 inch spider and some had a 6" spider. Mine is the 6".

Won't be getting the kits till later next week so in the mean time I'll have to bring the LST-2's back out.....not to hard to handle.

John

Link to comment
Share on other sites

Bummer about that blown 12" woof, but I'm finding it difficult to muster up too much sympathy when the back-up speaker is a pair of little old LST-2's.

Seriously though, this is indeed a disheartening setback, and we're all rooting for you to get those new speaks back in your dining room. Can't help but wonder, though - - - - is the Carver amp working properly and were the LST fuses operable?

Ditto about M Sound - I like them a lot.

Link to comment
Share on other sites

The Carver amp I bought about two years ago and had it serviced by Rita at Bob Carvers repair shop shortly after that. I have two Carver TFM-45's (both serviced by Rita) that have been driving my (bi amped) AR9's without a problem.

The fuse is in the LST's.

I'm guessing and only guessing that the woofer may have been weakened or damaged over the years and this just put it over the edge. I plan on reconing the other woofer too. I'll be checking it out very carefully for any damage when I take it apart.

In the AR3a restoration manual they talk about cracked voice coils. Maybe this one was already cracked. Of course there's no way to know that without taking the speaker apart.

I'll let you know how I make out with the reconing.....going to be a long week waiting for the parts......

John

Link to comment
Share on other sites

Talked to John from M_Sound today, you guys certianly nailed him.....what a great guy!

Gave me lot's of tips on reconing the woofer.

Expect to have the kits late next week and hopefully have the LST's back up and singing by the weekend.

I'll keep you all up to date on how the reconing goes....

Here's a pic of the Carver TFM-45, signed my the man himself when I sent it in for the tuneup/repairs.

John

post-102118-0-18058300-1332452122_thumb.

Link to comment
Share on other sites

Ok, guys. I've listened to your advice and decided not go with a Carver amp.

I'm looking at Crown amps, although not the prettiest looking beasts I hear they can deliver some serious power.

Can anyone suggest a particular model that would work well with the LST's?

Thanks,

John

Link to comment
Share on other sites

amps. That opens a can of worms. What about McIntosh, Hafler, Adcom, Bryston (that's all over the map I know)

Kent

Link to comment
Share on other sites

I don't see how you could go wrong with a 200 (or so) watts/channel McIntosh amplifier.

Crown is also a fine choice, at generally much lower prices than Mac; and previously-owned Crown amps are frequently found in music stores.

Here's the spec sheet for Crown's PS-400, which plays well with the AR-9 and AR-90 - lots of clean, reliable power - they usually sell for $300-$400 on the used market:

post-100370-0-52089500-1332624285_thumb.

post-100370-0-40505900-1332624301_thumb.

Link to comment
Share on other sites

John,

Curious on advise not to go with a Carver amp. All the other mentioned gear are fine amps.

I have been driving my LST's with either a Carver M1.5 or TFM-4.0 (same as a TFM-45) since about 1981. Around 1990, I switched to the TFM-4.0 driving the LST's, with the M1.5 driving a set of AR3a's as a subwoofer thru an electronic crossover (AR3's had some bad tweeters and mids). Reason I did that was modern recordings (especially pop) have so emphasized low end bass, I didn't want to break anything during parties and so on. I have played the combo at quite high volumes for a long period of time (parties).

Have never blown a mid or tweeter (amps have a lot of headroom), even with females complaining of the high volume.

However, for a chuckle, it was my wife that broke a voice coil on one of the 3a woofers during the 1812 overture by turning the volume up during a quiet passage just before the cannons.

Only problem with the TFM-45 I am aware of is they can motorboat (go full throttle without warning) as they get older... the older Carver amp, good in its day, had more of a "solid stateish" sound.

Not trying to offend anyone, just curious.

Joe

Link to comment
Share on other sites

John,

Curious on advise not to go with a Carver amp. All the other mentioned gear are fine amps.

I have been driving my LST's with either a Carver M1.5 or TFM-4.0 (same as a TFM-45) since about 1981. Around 1990, I switched to the TFM-4.0 driving the LST's, with the M1.5 driving a set of AR3a's as a subwoofer thru an electronic crossover (AR3's had some bad tweeters and mids). Reason I did that was modern recordings (especially pop) have so emphasized low end bass, I didn't want to break anything during parties and so on. I have played the combo at quite high volumes for a long period of time (parties).

Have never blown a mid or tweeter (amps have a lot of headroom), even with females complaining of the high volume.

However, for a chuckle, it was my wife that broke a voice coil on one of the 3a woofers during the 1812 overture by turning the volume up during a quiet passage just before the cannons.

Only problem with the TFM-45 I am aware of is they can motorboat (go full throttle without warning) as they get older... the older Carver amp, good in its day, had more of a "solid stateish" sound.

Not trying to offend anyone, just curious.

Joe

Joe,

I had suggested to John that he may want to try a different power source after reparing his woofer. I have restored and repaired a great many AR-3a's, and have only known one other AR woofer to go the way John's did, and an otherwise "normally" functioning Carver amp was strongly implicated in its demise. I personally owned a Carver M1.5t which was nothing but trouble, and it hated low impedances. This amp was used next to Crown, QSC, and Peavey in the same applications (not just AR) and was without a doubt the weakest perfomer of them all. Further, based on the shared experiences of others, reliablity appears not to be a Carver attribute.

This could all be coincidence...like you, just sharing some experience.

Roy

Link to comment
Share on other sites

I had to admit I've had very good luck with Carver equipment over many years (with the possible exception of the recent problem and I certainly can't confirm the TFM-45 was the culprit in this case).

I've mentioned before I'm currently using two Carver TFM-45's to drive my AR9's and have had zero problems. :)

At the same time I'm glad Roy made the suggestion to me to look at other amps as an option. I think sometimes we get stuck on certain brands and fail to realize there's other good stuff out there.

One particular amp I'm looking at is the Emotiva XPA-2 http://shop.emotiva....s/products/xpa2

I like the looks of it and seems to have plenty of power. I called their tech department and asked the guy how it likes speakers that dip below 4 ohms, he said it shouldn't have any problems at all.

I've done alot of reading over the years on Carver equipment and it seems people either love it or hate it and they all have very good reasons why. Kind of like Bose I guess......

Anyway, I'll be very honest here.....I go back and forth on what amp to use. I do like Carver stuff and I can get a very deal on the TFM-45.......

........and I truly value everyones opinions.

John

Link to comment
Share on other sites

Probably any of the suggested amplifiers will do the job with the AR-LSTs as long as there is adequate power, but many an amplifier has failed at the hands of a pair of low-sensitivity, low-impedance, capacitive-reactive AR-LSTs. It's just a very difficult load for any amplifier. I know this from first-hand personal experience: on separate occasions I completely destroyed one channel in a Dynaco ST-400 and seriously damaged a Marantz 250 amp trying to drive LSTs. I eventually ended up using McIntosh amplifiers because of the auto transformers, and there were never any problems after that. But that was then and this is now.

I've mentioned this before, but I found an amplifier recently that works great with these older AR speakers about any issues -- the professional Crown XLS series. For $299, one can buy the smallest version, a new Crown XLS-1000 Class D power amp that is stable down into 2 ohms. It has fan cooling, but the fan rarely ever operates unless the amp is pushed hard. This inexpensive little 8-pound amplifier puts out an impressive 215 watts/channel into 8 ohms and about 350 watts/channel into 4 ohms and all the way up to 550 watts/channel into 2 ohms. Insofar as this is a modern professional design, it is designed to take abuse, and it can be run wide open all day long if needed. The design is very quiet and effortless into any load, and it is backed by a three-year Crown factory warranty. The most important thing is that you have the confidence that it will not self-implode one day into your valuable, hard-to-repair AR-LSTs.

By the way, be sure to fuse the LSTs with Fusetron FNM-2 slow-blow fuses, if possible. However, fuses won't save a woofer from short-term excessive input power (e.g., the 1812 mistake), but they will protect the tweeters from most forms of abuse. Most likely the voice coil bottomed heavily on the back plate of the woofer (the AR woofer does not have a "bumped" back plate, and is thus more susceptible to excessive power at low frequencies).

--Tom Tyson

post-100160-0-72677700-1332799852_thumb.

Crown_XLS_Datasheet_CRO137.pdf

Link to comment
Share on other sites

tysontom,

I'm also looking into those amps too. Roy also mentioned crown amps....so there must be something to them.

Just seems hard to believe for $300 you can get something with such power. Then again for that price why not give them a shot! :D

Just wish they came in black instead of the Black/silver.

Never thought that PA audio type equipment would be a good candidate for home audio use. :rolleyes:

John

Link to comment
Share on other sites

I had my own chuckle with Joe R's comments about a motor-boating amplifier and the1812 overture - - - hey, you could experience both at the same time with a 4th of July boat ride on the Charles River in Boston for the fireworks display with the Boston Pops!

Next, I appreciate John's notions of brand loyalty (re: Carver) - - - I also embrace this attitude with many consumer purchases (clothing, cars, kitchenware, book publishers, food products, etc.) - - - but I do try to remain open to the ever-changing marketplace. Hey, look at all of us - - we are all still enthusiastically talking about Acoustic Research! I'd confidently say that's one version of dedicated brand loyalty.

Nonetheless, Tom T.'s amplifier comments are most interesting. I do not know much at all about the current state of consumer electronics, but since I'm originally from from northern Indiana, I'll always support the advocacy of Crown products (still made in Elkhart, I hope). Wow - - - for only $300, a 215/350 watt amplifier that can drive LST's all night long? And only eight pounds? Facetious perhaps but, I have to think that the faceplate and carriage of a Crown DC-150 almost weighed that much! This Crown amp series does indeed sound like a real contender for performance, but I do wish that the aesthetics of the industrial design of the product(s) had achieved a higher plateau - - - yes, perhaps it's all about the music, but these products make the old DC-150 and DC-300 look like beauty queens.

Buy one to drive your power hungry speakers, but just don't display it too prominently.

Link to comment
Share on other sites

John,

Look over those specifications on the Crown XLS amps. As far as SNR, high power, low distortion and power bandwidth, they are second to none. The reason they are relatively inexpensive is that with modern-design Class-D operation, there is less need for expensive large transformers and heavy power-supply components and so forth, thus the economy of scale. QSC, Crest and Crown and many others in the professional field sell probably ten-times+ as many amplifiers as those used in consumer applications. The competition is much stiffer, and the demands are far greater. The result is that professional amplifiers will typically easily outperform the consumer equivalents for far less money, and do it more reliably. Twenty or thirty years ago a PA amp or a disc-jockey amp might have been some cheap device with no bandwidth and high distortion, but today's pro amps are totally different! The only drawback in some designs is the presence of fan noise in some models. However, the attractive thing about the Crown XLS-series amps it that the fans don't cycle on unless there is heavy current output, so there is virtually no ambient noise. The XLS-1000 amp runs cool all the time, even when it's belting out a lot of power. Some very high-power professional amps do have fans running all the time, so you would have to put the amp where the noise wouldn't intrude.

I also have a QSC PLX-3600 Class-H amp, and it does develop some heat the moment it is turned on. The variable-speed fan starts with the amp turn-on. But this amp is capable of over 1100 watts/channel continuous output at 4 ohms -- 20 Hz - 20kHz -- both channels driven, at under 0.05% harmonic distortion. I have driven stacked, parallel-wired AR-LSTs with this amp, and there was no strain whatsoever. There aren't many consumer Class B or Class A/B amps that can equal this level of performance, let alone surpass it, and do it day in and day out. The QSC amp also comes with a six-year factory warranty.

--Tom Tyson

PLX2_spec.pdf

post-100160-0-90362200-1332819881_thumb.

Link to comment
Share on other sites

No, the XLS 202, etc., as shown in JKent's message, is the older series. It's all-black, for sure, but it's an older design (Class AB), heavier and has a constant-running fan. It's a fine amp, but not as advanced and compact as the newer XLS series (XLS-1000, etc.).

--Tom Tyson

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...