nemesis1 Posted April 8, 2004 Share Posted April 8, 2004 I had to try a new thread on this subject. Klipsch tec support said give you a shot! I have an older 1983 1984 set of La Scala with the AL crossover network. My k-77 M Tweeter has need of a voice coil which I have found. The magnet gap dose not have concentricity due to the notch plate and the back plate of the magnet becoming dislocated from the magnet. The magnet is not broken. The center piece has shifted which should be glued to the back plate. The concentricity of the magnetic gap is critical according to klipsck tec support. Can this be reassembled back at Hope, AR.? I am told that the K-77 M is no longer made. Klipsch has only the K-77 F horn tweeter. The F will not work with my AL crossover network. I am told if I use the 77-F I must replace both tweeters & crossover networks at a cost of $1,900.00 plus shipping! I am told that the Klipschorn & La scala use the same speakers and was hoping that I might find the right speakers or parts elsewhere other than Klipsch. Can any of you fellow Klipschorn & La scala Lovers offer this ole disabled vet some help. I have removed the tweeter horn & wire from the cabinet, is it safe to continue useing my surround sound with this speaker removed ? Your help & opinions are appreciated. Thanks Quote Link to comment Share on other sites More sharing options...
J.4knee Posted April 8, 2004 Share Posted April 8, 2004 Try contacting Al Klappenberger at(See below), he is also on this forum also Q-MAN is pretty sharp on your topic. alk@toad.net alk@alkeng.com Quote Link to comment Share on other sites More sharing options...
Q-Man Posted April 8, 2004 Share Posted April 8, 2004 I have only replaced diaphragms in these tweeters, I never had to go farther then that. I would have to check, but I think that I bought the diaphragms from Electro Voice for around $20.00 Check with BEC, I think he has diaphragms and may be of some help with the assembly. Quote Link to comment Share on other sites More sharing options...
klipschaholik Posted April 8, 2004 Share Posted April 8, 2004 My theory has always been if it was put together then it should come apart. I've replaced a couple of the diaphrams in tweeters and haven't had to do anything else but from what your saying the magnet has shifted which causes a miss alignement of the voice coil. Can you get the back plate off the speaker? If if was glued in place then you should be able to re align the magnet. I have some scalas out in the shop awaiting some new skin (veneer job). I'll look at the tweeter tomorrow and see if i can give you any more help. Don't give up yet! Quote Link to comment Share on other sites More sharing options...
J.4knee Posted April 8, 2004 Share Posted April 8, 2004 This should help http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=50597&item=3089729852&rd=1 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=61378&item=3089984583&rd=1#ebayphotohosting http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=61378&item=3089995423&rd=1 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=61378&item=3090664779&rd=1 Quote Link to comment Share on other sites More sharing options...
formica Posted April 8, 2004 Share Posted April 8, 2004 ---------------- On 4/8/2004 3:45:24 PM nemesis1 wrote: The magnet gap dose not have concentricity due to the notch plate and the back plate of the magnet becoming dislocated from the magnet. The magnet is not broken. The center piece has shifted which should be glued to the back plate. The concentricity of the magnetic gap is critical according to klipsck tec support. ---------------- Tech support is correct about the importance of the gap. I hadnt realised that the pole piece is glued to the back plate, as I was under the impression that they were machined in one piece. Repositioning/gluing it with high precision will be very difficult. You could try placing identical shims around the pole piece in the gap to try to center it as the glue dries (Ive seen similar techniques used to center a cone when re-foaming it). Problem in this case is, I believe, the magnets flux will attract the pole piece as you try to center it making it impossible to do well without first removing the magnet. Perhaps hunting one down on Ebay, as suggested, may be the best solution. Good luck... Rob Quote Link to comment Share on other sites More sharing options...
BEC Posted April 9, 2004 Share Posted April 9, 2004 The K-77M (T-35A) uses a plastic ring around the pole piece to center the pole piece at the top to form the concentric magnet gap. The pole piece is also held in place by a dot of glue at the back. Over time the plastic ring deteriorates somewhat and tends to slip down the pole piece where it no longer positions the top. All that is left then to keep the pole piece centered is the glue dot at the other end. A small shock to the tweeter will then dislodge the pole piece and cause it to move with great force to the edge of the gap. That of course then pins the voice coil and destroys it. Putting it back together is a difficult process since the magnet is quite strong and tends to pull the pole piece out of alignment during reassembly. My replacement tweeters I am building eliminate this plastic part and instead use a precision zinc plated machined top plate with a neck that centers the pole piece. These do not have to use glue to hold the pole piece. The older alnico K-77 (EV-T35) uses a welded ring on the bottom of the top plate to position the pole piece. If one of those has this centering problem, it would likely be because the weld has broken. Bob Quote Link to comment Share on other sites More sharing options...
JohnA Posted April 9, 2004 Share Posted April 9, 2004 Your tweeter is toast. You will have to replace it; that will be cheaper than fixing it. Ebay usually has several for sale. The K-77-M is an E-V T-35A. Go ahead and buy one; it will be less than $100. You will be much happier with your La Scalas if you change the crossover. We have the schematics for the older types and you can build it yourself. As an alternative you can buy prebuilt crossovers from Al Klappenberger or Bob Crites. I have a pair of Al's crossovers and they are great, but expensive. I'd recommend the Type AL-3 first. The simpler Type AA should work, but should be modified slightly to reduce the overlap of the squawker and tweeter. You will not damage either the speaker system or amplifier if you use it with the tweeter removed. Oh Yeah, my opinion? You're ugly and your feet stink. Quote Link to comment Share on other sites More sharing options...
formica Posted April 9, 2004 Share Posted April 9, 2004 Bob... you selling/manufacturing these repro K-77M tweeters? Seems like a good extension to your diaphragm offerings, given the popularity of the T-35A. Rob Quote Link to comment Share on other sites More sharing options...
djk Posted April 9, 2004 Share Posted April 9, 2004 "You will not damage either the speaker system or amplifier if you use it with the tweeter removed." An A, B, or E type will be OK. The tweeter inductor will burn up in a AA type if played loudly without the tweeter. It can also cause amplifier problems. Quote Link to comment Share on other sites More sharing options...
BEC Posted April 9, 2004 Share Posted April 9, 2004 Rob, Yes, I can build a good number of the tweeters now. One forum member has had a pair of them for a few weeks now. Bob Quote Link to comment Share on other sites More sharing options...
nemesis1 Posted April 10, 2004 Author Share Posted April 10, 2004 John would I have to change out the K-55 M & K-33 as well ? I look at it this way John & Bob C. The old Khorns & LS have a vary Distinct sound! They are classics. I know all ears are different but for me that is why I selected Klipsch! I looked & listened. I wanted the Khorns so bad. The last I checked they are around 8500 each. The La Scalas last I checked are around 1850 each. even back when we were much younger they were still a vary expensive for the time. What I am saying is that as I was reading on the forum a few days ago. I think it was a previous employee. He was stating that the pre. 85s were made by men & (women) that were gone by that time. Even tech support at clipsch and I were talking. When they quit making the K-77 & K77 Ms to include the old crossover networks The PRE Klipschorns & La Scala became Classics and were gone forever, with the exception of the original replacement parts all ovet this country & overseas. Even the original sound that built the Famous Klipsch name, is for the most part is gone! I would like to keep the classic sound they have even if it is only 2 or 3db. Kind of like people who take old cars & restore them. I know one thing! I have had the pleasure to somewhat meet/read alot of Klipsch Lovers here on the forum. What do you think B.C. & John? Let's keep the old classic sound alive & play it LOUD & PROUD!!! Quote Link to comment Share on other sites More sharing options...
formica Posted April 10, 2004 Share Posted April 10, 2004 ---------------- On 4/10/2004 1:14:04 PM nemesis1 wrote: John would I have to change out the K-55 M & K-33 as well ? ---------------- Nope... like mentioned, you just have the get a used or refurbished K-77M unit, and it will plug right into your existing x-over... preserving the *original* sound. Unfortunately these arent available from Klipsch, BUT are readily available on Ebay. A pair of functioning units should set you back between 100$ and 150$ (single units are rare, but should cost you less than half). Good luck... Rob Quote Link to comment Share on other sites More sharing options...
J.4knee Posted April 12, 2004 Share Posted April 12, 2004 Dave, The links I posted earlier are links for K-77/M tweeters available on E-bay. These should/will plug directly into your existing networks. I did not notice what networks you have, but looking at the year of your La Scala's, I am going to assume they are probably AL series. Al K, referenced earlier in this thread, offers both parts kits and matched assembled networks series A networks that are direct replacements for your networks. These networks have changes made to enhance/improve the sound. Your networks are like mine 20+ years old, with component aging and other intangibles their sound has probably degraded some, I know mine has. I am going to be placing an order for the kits with Al this week. Just about everyone that I have read about who has done this mod are very pleased with what their La Scala's sound like. I completely understand your wish/desire to maintain/restore the sound that was originally built into your La Scalas. I feel the same way. Good luck. Jim Quote Link to comment Share on other sites More sharing options...
JohnA Posted April 13, 2004 Share Posted April 13, 2004 Davis, I don't think anybody recommended replacing the woofer. New K-horns are $7500 a pair and sell for less, often enough. They sound much like always, but are smoother than I remember. The voicing has changed little from the '70s to the 2003s. I never tried the K-55-M drivers with my Type AA crossovers. With the Type AL, the sound is truely awful and certainly NOT the Klipsch classic sound. I have been told the K-55-M sounds "honky" through the Type AA by people I trust. I have been told the K-55-M has the same sensitivity as a -V. When I changed my -Ms for -Vs, the mids seemed slightly lower, but that was in the rear channels and they were difficult to isolate for critical listening. If I were you, I'd replace the Type ALs with Type AL-3s, ALKs, or build my own hybrid of the Type AA/ALK networks. Quote Link to comment Share on other sites More sharing options...
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