frankmarsi Posted April 28, 2018 Report Share Posted April 28, 2018 4-27-18 Reaching out to members who know about this speaker. I’m planning on replacing all of the capacitors in my LST speakers as I feel they’re long over due. I’ve read about an AR change of one capacitor value here: http://www.classicspeakerpages.net/IP.Board/index.php?/topic/4198-roy-allison-ar-3a-ar-lst-mark-levinson-cello-amati-speakers/&page=2 According to the post from a very dearly missed member “Minh Luong” (I wonder where he is these days?), apparently AR had cited a change of one of the ‘caps’ that was decided later on when the speaker was already in the field. At the same time, I also plan on changing all of the original tweeters and substituting them with used but operating AR-9 tweeters as in the last couple of years I have purchased 20 of the AR-9 tweeters used. This work will require 16 tweeters. I could replace the front two only as some folks recommend however, as long as I’m at it I may as well install all four per cabinet. In addition, I would need to know what type of ‘cap’ I should use, whether polarized or not, the brand name, build type, etc. The reason that has moved me to finally do this procedure is that I noticed a slight ‘thump’ sound every once in a while emanating from one woofer, the other three woofers are not making this noise. At first I suspected it may have been one of the double amplifiers I’m using but, as time has passed I’m feeling it may actually be a X-over capacitor that’s to blame. I’ve learned in the past, that when a large amplifier ‘cap’ goes, it’ll go in a furious display of abrupt and horrific noises. SInce I’ve used these four LSTs steadily since 1989 with a slight non-use period between 1994 to 1998 when they sat idle, it may be high time. Though, since 1998 to the present they have been used regularly and enjoyed practically everyday. While I’m at it, the chance to replace the ‘caps’ in my third set of LST’s might as well be done at the same time. Any advise, methods and prior experience would be greatly appreciated. FM Further reading: http://www.audiocircle.com/index.php?topic=137644.0 https://www.vinylengine.com/turntable_forum/viewtopic.php?f=85&t=42191&start=30 http://www.classicspeakerpages.net/IP.Board/index.php?/topic/3853-bypass-caps-on-ar-lst/ P.S. for the inquisitive, I have no intentions of tri-amping, or removing the transformer. Also, both amplifiers were completely rebuilt by an industry premier rebuilder in 2009. Link to comment Share on other sites More sharing options...
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