Acoustic Research LST-2 .... Drug them out finally

Discussion in 'Speakers' started by Galaxie65, May 16, 2018.

  1. Galaxie65

    Galaxie65 Always looking for new gear to try Subscriber

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    Well I finally dug out these out and I'm going to see if I can bring them back to life. They are currently playing very, very low. I'm going to start pulling the drivers out and testing them to see if they are open or what the readings are going to be. So far so good, I pulled two drivers and got around 6 ohms. So fingers crossed and pictures to come.

    They are an interesting speaker, I always want to have some different and rare speakers. I think these fit the bill nicely and they don't take up too much room to boot.

    Anyone have some thoughts on these? Is it worth it to recap or run the caps that are inside still? I have an idea of what most will say, but is there anyone that has caps that are ideal for these? Also I read somewhere that an added inductor was essential, is that the case?

    Thanks guys!
     
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  2. StimpyWan

    StimpyWan AK Subscriber Subscriber

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    Do the LST-2's have fuses? I ask, because the fuses AR used back then, can slowly degrade, and cause diminished output. As such, the fuses probably need replacing. The LST's experience the same fuse issues too.

    Good luck. And nice speakers. I'd like to own a pair as well. :thumbsup:
     
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  3. GD70

    GD70 AK Subscriber Subscriber

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    These are very good speakers with good caps. I wouldn't change them. Mine had six dead tweeters, and did the HiVi swap, with a cap mod and air core coil on the tweeter circuit as Roy C. suggested.
    These have an uncanny ability to bend sound and surround you with it, very dimensional.
    How are the woofer surrounds! If they need replacing, you'll need the Boston fillet style as they are correct.
    If any of your tweeters are dead Chris is rebuilding them now. This wasn't an option when I restored mine, and Roy said the tweeters wer paper weights, and stupidly tossed them.
    Post some pics when you get a chance.
    I have a pretty extensive restoration thread as mine needed a lot of work, reveneering, and all six grille frames glued back together and new cloth.
    Cheers, Glenn
     
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  4. GD70

    GD70 AK Subscriber Subscriber

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    Yes they do, and your suggestion is an excellent one.
     
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  5. Galaxie65

    Galaxie65 Always looking for new gear to try Subscriber

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    Thanks! Here is a few ok shots of them in the garage.

    I started addressing the veneer a little, haven’t dug in like I normally do.

    Glenn you have an awesome thread, I just couldn’t see the pics anymore

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  6. StimpyWan

    StimpyWan AK Subscriber Subscriber

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    They look great! All rear wired mids and tweeters too, which looks much cleaner. I wonder how hard they'd be to reproduce??? :naughty::) Do they have that weird transformer as well, like the LST's? :idea:
     

     

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  7. GD70

    GD70 AK Subscriber Subscriber

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    Yes, they have the transformer, & big Sprague caps. It's a pretty complex crossover.
     
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  8. GD70

    GD70 AK Subscriber Subscriber

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    Thanks to PB for messing up the photos.
    I need to delete and relink them, a PITA but should be done.

    Yours look pretty good with minimal cab work needed.
    So all drivers are working for sure?
     
  9. Fairlane

    Fairlane AK Subscriber Subscriber

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    Those look great already. Would love to hear a pair of those sometime.

    You are in good hands with Glenn on this thread.
     
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  10. gdmoore28

    gdmoore28 Super Member

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    Like others, I've always loved the look of those speakers, but I'm waiting yet to hear them, except for the wonderful exhibition on Glenn's thread. Thanks for rescuing another pair from total loss.

    GeeDeeEmm
     
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  11. sberger

    sberger Hard Core Geezer Subscriber

    Legendary speakers, fairly rare and go for big prices. Definitely restore properly and enjoy. I wish I could find, and afford a pair.

    Look forward to watching the thread develop.
     

     

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  12. 45rpmspinner

    45rpmspinner Active Member

    I'd give my right arm to have a pair of LSTs.
    Actually, no., that's incorrect...I'd give someone else's right arm to have a pair.
     
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  13. Galaxie65

    Galaxie65 Always looking for new gear to try Subscriber

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    Thanks guys I'm excited to get the ball rolling. I'm going to pull the drivers today I think before work and check them all. I'm hoping that I will strike gold and they will be operational. However I know how much these can degrade and even be completely trashed. When I last hooked them up I was getting very, very, low volume from them. So as a precautionary measure I'll go through the motions to check it all. Could the XO be the root cause if the drivers all test within spec?
     
  14. StimpyWan

    StimpyWan AK Subscriber Subscriber

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    Remember, CSP member Chris1this1 can repair the tweeters, if needed. So, no need to trash drivers, like some others do. :p

    Good luck.
     
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  15. GD70

    GD70 AK Subscriber Subscriber

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    I wish Chris was doing these repairs when I was restoring mine. His work is outstanding. I've heard his LST's, LST-2's at the Blue Mountain Lodge meet last year, as well as having Chris restore a pair for a set of 3a's I restored for a client.
     
  16. StimpyWan

    StimpyWan AK Subscriber Subscriber

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    I am truly sorry that you trashed your tweeters. That's definitely a heart breaker. But, I've done silly stuff like that too. I guess we all have?

    Also, it's very good to hear that Chris's repairs are better than good. Our old AR's deserve that type of respect and support. Classic speakers, and worth the restore.
     

     

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  17. GD70

    GD70 AK Subscriber Subscriber

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    Chris is also on AK as CJVx.
     
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  18. GD70

    GD70 AK Subscriber Subscriber

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    At that time, Roy C. said the tweeters were useless paper weights, they were unrepairable. Unfortunate indeed, I usually don't throw stuff like that away.
     
  19. cwh

    cwh AK Subscriber Subscriber

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    @CJVx just completed a pair for me. Got one installed last night. Excellent work!

    Great LST project. Keep it up.


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  20. Galaxie65

    Galaxie65 Always looking for new gear to try Subscriber

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    Thanks guys, how much does it normally run to repair the originals? I might have to look into that.

    I took a meter to a pair the other day and from the back I was getting around 6. However today before work I tossed the meter on the front and was getting a very different reading from the exposed leads. I’d say the 1.0-.8 range. So does that mean I’ve got a break inside or is there something I’m doing wrong?

    I have the surrounds on the way for the 10”. Hoping that I can get them squared away and move to the next phase of the project.
     

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