KLH 6 -- untouched by age (assistance will be needed)

[dabraham]

Hi All,

Been following the forum for a bit and I've already soaked up every ounce of brilliant help out here and in audiokarma. Awesome community!  I'm a professional musician (conductor) and my college roommate some many decades ago, who worked for a pro-audio shop just outside Boston (will keep this nameless for the moment -- nothing notorious) purchased a pair of white painted 6s back in the late 1980s. He has since sold them , but I never forgot them. Absolutely astounding. Hoping I have found the same in the pair I just purchased. So far, I think so (and then some).

 

Purchased: KLH 6 pair #132746 & #132733. Based on Ken's Early KLH Speakers, Systems, and Components chart, dating I've found else where, the flat plate with completely screw removable components and 15K per year production from that era, I'd guess 1966 or 67 (I'll let you know when the woofers come out tomorrow). Looks to be solid walnut cabs (see rear corner photo -- no veneer, right?) Every ounce of both these bad boys seem to be original - even the edge of what seem to be--now turning to powder/disintegrating--gaskets under the tweeter grating are still visible (see tweeter pic). Damn, I don't think the grills were ever removed - what looks like dirt on the fabric are just shadows from my poor overhead lighting. Only thing missing, I can tell, are the rear nuts on the badges (or maybe there were never any). Cabinets are in 98% mint with the foot prints from an amp or other component visible on the finish, a handful of minor dings and dots, and a bit of dulling (only on the tops) from some kind of furniture polish. Excited to tear into these but want to make sure every step is done right.

 

So, based on my first observations, time to purchase:

(1) some surround seal goo by RoyC via Vintage_AR;

(2) start an order for the following caps: two 2uF and an 8uF cap per speaker [or two 4uF caps in parallel for the 8uFs]. Any particular brand preferred. Any modification to consider (seems like "no" is the right answer to the latter)

Do I need anything else?

 

Humble apologizes to Ken as I purchased these in your state. I had to drive 2 hrs, but well worth the trip.

I'm in the middle of moving so it's going to be another couple of weeks before I get to work on these, but I'll get a look and some pics of the XO within a day or two and send just to have someone knowledgeable double check my order list.

 

Warning: KLH 6 porn attached.

 

Dan

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[dabraham]

Ok, the moment I stopped typing, I took out a woofer. Date Stamp: May 20, 1969 (I'll let you know the other components as we go).

So, looking at the woofer basket, magnet and backplate: have these been reworked in such great detail or has time stood still since 1969?  Additionally, see the tweeter grate -- looks like it just came from the warehouse (practically new old stock?) -- the goop around the grate tells a tale of age, but the metal components look too new to be true. 

Also, see the interesting circle-J stamp from between the woofer and tweeter -- anyone see this marking before?

I guess I need to stop and just hook them up for a listen before doing much else. Unfortunately, because I am moving, nothing else is in the old house -- Argh. No possibility of a listen for at least four days. Push test on cone shows expected leaks (comes right back). Guy who sold them to me told me a friend received them from an older retiree along with a bunch of other mint vintage gear.

Tell me this is not some kind of wack-job over-buffing on the woofer parts or are these just a gem example of this vintage? Even the screws look too new but they do look original based on others I have seen on this site (aging is just perhaps consistent with all the rest). There is white cloth under the woofers -- not the black I have commonly noticed (any one know when that color might have changed or is this replacement material?)

Based on all the details, however, I'd like to think this is all stock and just well preserved, but I would love to hear what the experts in the community can tell from the photos.

Dan

 

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[JKent]

Welcome to the CSP dabraham!

That's a real nice pair of speakers! If I may make a suggestion, it looks like you downloaded pics from your iPhone and the file sizes are huge (close to 2MB each). If you have a way to do it, try resizing your photos first. About 100KB or so is good.

Beautiful walnut, yes, but it's veneer, not solid, so be careful if you do any sanding.

I'd say "yes" to Roy's goo and new capacitors, "no" to any special brand (that only opens up a can of worms). Many here buy Dayton film caps from Parts Express and if you go that route I'd suggest some of their goam 3/8" gasket tape for the woofer. Leave the tweeters in place and they'll probably be OK.

The stains on tops that you mention seem like ideal candidates for Howard Restor-a-Finish.

Enjoy the music!

Kent

[dabraham]

Hi All,

 

Yes, my error -- re-posting at reasonable size here.

Yes, veneer -- got it and noticed soon after I sent.  In fine shape throughout except a couple treatable chunks. Lacquered with patches missing or blotchy on sides but with plenty remaining material so Howard's Restore is perfect and already own some. Before that I'll also do a vinegar and water cleaning (50%/50%) of the tops  -- apply and wipe; repeat -- simple way to remove wax left over from commercial cleaning products. Then watco danish (med walnut, I assume). Family was in the antique biz so furniture refinishing is a strong skill (it's the XO I'll need to triple check with everyone). My wife has access to all kinds of microcrstalline waxes too so I'll do some testing if the initial finish comes out as expected (even if I only do the tops).

 

Should I replace the rotted gaskets under the tweeter grills? OR just don't bother opening them up unless there is a problem?

 

The Woofers: yes, will dope the surrounds. The "stringy" stuff in the R woofer is cover fabric shreds. What adhesive to repair the surround's attachment to the cone? I can fix the places where the surround is tucked under itself. None of it is actually detached, but showing signs of time and/or hurried work. I can fix that with a little bit of careful attention, a spatula, and the right adhesive. Some minor detaching (see detail).

 

Once I move and get these to a space, I'll send some properly lit pics of the finish and the woofers. In the meantime, these are the ones from earlier that did and did not load (much lower res -- I'll aim in between next time  

Thanks all,

Dan

 

The bits of "string" are cover cloth shards.

Cloth insert; putty is really clean too -- but not new.

Circle-J marking; quality control from the Singer years?

[JKent]

By "gaskets under the tweeter grills" do you mean that gray crumbly foam sticking out of the top? That's a sealing gasket behind the tweeter flange (not behind the grille). I would not touch the tweeters unless there's a problem. If, once the woofers are all sealed up, there is still an air leak then it might make sense to make new tweeter gaskets. You can cut them from a thin foam craft sheet sold by Michaels https://www.michaels.com/12x18-foam-sheet-by-creatology/10489300.html

For the woofer gasket, scrape off all the gray putty and use this https://www.parts-express.com/parts-express-speaker-gasketing-tape-1-8-x-3-8-x-50-ft-roll--260-540

Caps are here https://www.parts-express.com/cat/metalized-polypropylene-crossover-capacitors/294 BUT look at them first. Early 6s had two 2uF and one 8uF OIL caps. Those should not be replaced.

I've never had to reattach a cloth surround so I'm not sure what adhesive to use. Hoping another member will advise. Actually I don't really understand what the issue is (and after saying your pics were too big I'm afraid now the resolution is so low I don't see where the surround is tucked under itself). 

btw, the white cloth behind the woofer is exactly what I've seen in many other KLH speakers.

Kent

 

 

 

 

 

Edited November 23, 2022 by JKent
Removed pictures

[JKent]

PS: regarding the woofer surrounds. Aleene’s Tacky Glue would probably do it. 
I use it for foam surrounds, dust caps, grille cloth, ....

[dabraham]

Hi All,

 

Just getting back to these and had a chance to remove woofers and all batting so I could view the XO.

 

I see the 8uf clearly (see pics), but the two other are within the goop at the back plate. None of these are the older oil filled caps so I need to take them out of that adhesive mess, right?  Heat gun slowly? Any best method? Can I assume they are straight up 2uf caps?  So, ordering some 2x2uf and 1x8uf per speaker.

 

With some advise, I'll be ready to make a parts order.

Thanks,

Dan

Thanks,

Dan

[JKent]

Although I have not done it myself, I think others have written that the potting used by KLH is a kind of epoxy and that it is hard and brrittle so it can be broken up by hitting it with a hammer (wear safety glasses).

As an alternative, if you can identify the common black wire from the 2x2uF cap, maybe just cut that and the 2 red leads that go to the switch and splice 2 new 2uF caps in and don't touch the potting.