KLH Model 6 repair

pvs

New Member
I uncovered a pair of KLH model 6 speakers serial numbers 003756A and 003747A in my mother in law's attic. The cabinets are in good shape, but there is no output from the tweeters. My guess is that these were made early in the model run, since the cabinet is epoxied together and there is no zip code on the backplates. Threads on AK suggest that either the crossovers capacitors or tweeters (or both) are bad. Since there is nothing to lose, I'd like to attempt repair. What is the best way to proceed?
 
One newbie to another. Have you checked for loose connections or tried a simple cleaning of connections and the switch (my KLH mode 17s have a tweeter switch)with a QC electronics cleaner?
 
Capacitors may need replacement, lots of info on AK about that, it's really a simple procedure, although you may have the non-removable woofers, making it more difficult. The KLH experts will be here shorty.
 
Well all you can do first is play with the pot adjustments, turning them back and forth while hooked up to a source and try and listen for life from the tweeters. sometimes you can hit a little spot on the pots that will let the signal through. That way you know if the tweeters have life left in them. Beyond that, you will have to go in through the back under the terminal plate which can be removed carefully. Then chisel out the epoxy. Plenty of threads on that fun process to dig up on here.
 
I’ve never taken the plate off. However, it seems as if you could spray some cleaner in that switch or pot and work it.
 
Welcome to both new members. AK is a great resource. My first advice would be to do some extensive reading so you become familiar with the issues - - type this exact phrase into your search engine for plenty of threads on the KLH Six (not 6):
site:audiokarma.org "KLH Six"
 
Well all you can do first is play with the pot adjustments, turning them back and forth while hooked up to a source and try and listen for life from the tweeters. sometimes you can hit a little spot on the pots that will let the signal through. That way you know if the tweeters have life left in them. Beyond that, you will have to go in through the back under the terminal plate which can be removed carefully. Then chisel out the epoxy. Plenty of threads on that fun process to dig up on here.
 
Thanks. I'll give it a try. The SIx model is epoxied together more tightly than most boat hulls, so getting inside is a last result.
 
I did an extensive restoration on my early Sixs. Look up my thread, just about all your questions should be answered there.
Cheers, Glenn
Just picked up a FREE pair of KLH 6's from original 1963 owner-PIC's
 
Thanks. I'll give it a try. The SIx model is epoxied together more tightly than most boat hulls, so getting inside is a last result.
I was reading a few restoration threads on the old KLH speakers and it looks like the easiest way to get to the crossover is by removing the driver. Be sure to read the thread mentioned below and have a paper bag ready to hold the fiberglass insulation. My model 17s were restored by whoever had them before me and they sound awesome. As far as the wood veneer on the cabinet, clean them with a cloth dampened with some warm water with murphy's oil soap. ( a capful of soap to a cup of warm water) glue any lifted veneer, then buy some natural color restore-a-finish by Howard. It's great stuff. Wipe on, wipe off. It ever so slightly dissolves the existing finish momentarily and leaves a very nice uniform look.
 
I did an extensive restoration on my early Sixs. Look up my thread, just about all your questions should be answered there.
Cheers, Glenn
Just picked up a FREE pair of KLH 6's from original 1963 owner-PIC's
Sorry to be ignorant, but I'm not sure how to find your thread. " Thread tools" doesn't give me any options
 
Thanks! i found the specs for the Duncan capacitors in the link as well. I haven't done anything like this since I used to scrap army surplus stuff to build ham radios a long time ago
 
I was reading a few restoration threads on the old KLH speakers and it looks like the easiest way to get to the crossover is by removing the driver.

Early Model 6's are a very different beast than your Model 17's.
You cannot remove the the epoxied-in woofers....and while it may be possible to remove the tweeters, I don't recall seeing anyone do it unless they were well and truly shot.
 
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I was reading a few restoration threads on the old KLH speakers and it looks like the easiest way to get to the crossover is by removing the driver. Be sure to read the thread mentioned below and have a paper bag ready to hold the fiberglass insulation. My model 17s were restored by whoever had them before me and they sound awesome. As far as the wood veneer on the cabinet, clean them with a cloth dampened with some warm water with murphy's oil soap. ( a capful of soap to a cup of warm water) glue any lifted veneer, then buy some natural color restore-a-finish by Howard. It's great stuff. Wipe on, wipe off. It ever so slightly dissolves the existing finish momentarily and leaves a very nice uniform look.

That's not going to work with this version of the KLH Six.
 
Well all you can do first is play with the pot adjustments, turning them back and forth while hooked up to a source and try and listen for life from the tweeters. sometimes you can hit a little spot on the pots that will let the signal through. That way you know if the tweeters have life left in them. Beyond that, you will have to go in through the back under the terminal plate which can be removed carefully. Then chisel out the epoxy. Plenty of threads on that fun process to dig up on here.

Never seen Sixes with a potentiometer for tweeter output adjustment.
 
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