KLH Model 20

[Analogman]

A friend of mine has a pair of Model 20s.

Are their drivers of any interest?

I haven't seen them in a while, but I think the cabs are a little rough; the drivers are all in nice shape.

He wants to move them to free up space.

Should I advise him to sell as a whole or part them out.

OR, are Model 20s worth a restoration?

Any insight would be well received,

Craig

[JKent]

They are nice speakers--virtually identical to the well-regarded Model 17. The 17s are 8 ohm, the 20s are 4ohm (but both use the same tweeters) The 17s have binding posts, 20s have RCA jacks--they were sold as part of the Model Twenty system with TT/receiver.

I have restored 2 pair of 20s and added binding posts. They are not worth much for resale, but if you like the sound they can be a bargain. Only caveat: Be sure your amp can handle 4 ohm loads.

BTW--before using these speakers, you WILL have to replace the caps. The ones I've seen used the notorious PVC encapsulated craps--black with red ends. They fail. They explode. They destroy drivers. Very very bad.

Good luck

Kent

[Analogman]

They are nice speakers--virtually identical to the well-regarded Model 17. The 17s are 8 ohm, the 20s are 4ohm (but both use the same tweeters) The 17s have binding posts, 20s have RCA jacks--they were sold as part of the Model Twenty system with TT/receiver.

I have restored 2 pair of 20s and added binding posts. They are not worth much for resale, but if you like the sound they can be a bargain. Only caveat: Be sure your amp can handle 4 ohm loads.

BTW--before using these speakers, you WILL have to replace the caps. The ones I've seen used the notorious PVC encapsulated craps--black with red ends. They fail. They explode. They destroy drivers. Very very bad.

Good luck

Kent

Thanks you for your insight. Your feelings on KHL caps are well documented here. I will certainly check them out if it comes to it.

What would be a fair offer for a pair that needs everything: finish refresh, grille cloth, caps, binding posts and switch service.........

Basically a working pair in need of everything to really make 'em shine.

I ask in case I decide I want them.

Thank you again,

Craig

[Analogman]

Please don't suggest checking completed ePay auctions; I consider that a barometer for nothing.

That practice, in particular, has caused great harm to this hobby, suffered most by the folks who are in it for the Love and Music of it.

What do you think is fair to someone that knows, loves and appreciates KLH, not a mercenary or box cannibal?

Regards,

Craig

[JKent]

As I said, they are nice but not worth much, which could make them a bargain. I recently refurbished a pair--new Dayton caps, refinished cabinets, new gold plated binding posts in parallel with the RCA jack, new speaker cloth. Total investment about $70 including the price paid for the speakers. I sold them on consignment at the local electronics shop for $99, so after the seller's take I about broke even. That was OK by me, because it was just a fun project and I'm glad someone is enjoying them.

[Analogman]

As I said, they are nice but not worth much, which could make them a bargain. I recently refurbished a pair--new Dayton caps, refinished cabinets, new gold plated binding posts in parallel with the RCA jack, new speaker cloth. Total investment about $70 including the price paid for the speakers. I sold them on consignment at the local electronics shop for $99, so after the seller's take I about broke even. That was OK by me, because it was just a fun project and I'm glad someone is enjoying them.

I'm going to be the new owner this afternoon for $10 bucks.

The plan: Clean them, check and test drivers, new caps, clean and seal surrounds as needed, strengthen spider to basket glue joint, install binding posts.....

THEN........ENJOY and LEARN. It's been longer since I've heard a solid pair of KLHs than it has for ARs.

Thanks,

Craig

[JKent]

I'm going to be the new owner this afternoon for $10 bucks.

The plan: Clean them, check and test drivers, new caps, clean and seal surrounds as needed, strengthen spider to basket glue joint, install binding posts.....

THEN........ENJOY and LEARN. It's been longer since I've heard a solid pair of KLHs than it has for ARs.

Thanks,

Craig

Ten bucks! Great!

Here is a photo of the 1st pair I did. The grille cloth is off-white burlap from JoAnn's. It looks sort of like the boucle KLH used on many speakers and it was cheap. But I'm a little concerned it may not be as acoustically transparent as linen or "speaker cloth." The 2nd pair has linen grille cloth. Suggestion: If the wood has no major chips, try Howard's Restor-a-finish. It's available at Home Depot, some hardware stores and online. Try googling to find the mfg home page. The stuff goes on with steel wool. Wipes off. Easy and great results. You can also get "screw protectors" at the hardware/Home Depot/Lowes. The green ones are the right size to fit over the RCA jacks. Don't know how critical it is, but if you use the binding posts the caps on the jacks will help maintain the acoustic seal. KLH did that on the Model Twenty One radio.

Good luck

Kent

[Analogman]

Ten bucks! Great!

Here is a photo of the 1st pair I did. The grille cloth is off-white burlap from JoAnn's. It looks sort of like the boucle KLH used on many speakers and it was cheap. But I'm a little concerned it may not be as acoustically transparent as linen or "speaker cloth." The 2nd pair has linen grille cloth. Suggestion: If the wood has no major chips, try Howard's Restor-a-finish. It's available at Home Depot, some hardware stores and online. Try googling to find the mfg home page. The stuff goes on with steel wool. Wipes off. Easy and great results. You can also get "screw protectors" at the hardware/Home Depot/Lowes. The green ones are the right size to fit over the RCA jacks. Don't know how critical it is, but if you use the binding posts the caps on the jacks will help maintain the acoustic seal. KLH did that on the Model Twenty One radio.

Good luck

Kent

Thanks!

Anything special about the three lead caps?

Yeah $10 bucks, and he threw in a single model "Six" that I'm looking at/posting about, right now.

Thanks again for your help,

Craig

[JKent]

Anything special about the three lead caps?

Yes! They are typical red and black PVC "craps" and SHOULD be replaced! two 2uF and one 8uF per speaker. Mylar is a good choice. Poly is good too but costs a bit more. For cheap, you could use non-polar electrolytics. They'll be good for another 20 years. But if you are going to expend the effort I'd say spend a couple of bucks more and go with mylars: Carli 8uF are $2 ea. Carli 1uF are 60 cents each. You can parallel them, or 2uF Solens are 2.20 each:

http://www.madisound.com/about/capacitors.php

or get Daytons at PE (that's what I used). 2uF about $2 ea, 8.2uF under $4 ea

http://www.partsexpress.com/dayton-metallized-capacitors.cfm

Kent

[Analogman]

Yes! They are typical red and black PVC "craps" and SHOULD be replaced! two 2uF and one 8uF per speaker. Mylar is a good choice. Poly is good too but costs a bit more. For cheap, you could use non-polar electrolytics. They'll be good for another 20 years. But if you are going to expend the effort I'd say spend a couple of bucks more and go with mylars: Carli 8uF are $2 ea. Carli 1uF are 60 cents each. You can parallel them, or 2uF Solens are 2.20 each:

http://www.madisound.com/about/capacitors.php

or get Daytons at PE (that's what I used). 2uF about $2 ea, 8.2uF under $4 ea

http://www.partsexpress.com/dayton-metallized-capacitors.cfm

Kent

Hi Kent,

My "20"s only have (1) 2uf and (1) 8uf cap per box. I've already ordered the Daytons. I'm using (2) 4ufs to make up the 8.

Thanks for your help,

Craig

[JKent]

Hi Kent,

My "20"s only have (1) 2uf and (1) 8uf cap per box. I've already ordered the Daytons. I'm using (2) 4ufs to make up the 8.

Thanks for your help,

Craig

Hi Craig

Take a look at the original "2uF" caps. You should see one lead coming out of one end and TWO leads coming out of the other end. It is probably marked "2 x2MFD" or something like that. It is a double 2uF and has to be replaced with two 2uF caps. You are fine with the two 4uFs to make an 8, but the 8.2 would have been fine. Any value between +/- 20% is good.

Good luck

Kent

[Analogman]

Hi Craig

Take a look at the original "2uF" caps. You should see one lead coming out of one end and TWO leads coming out of the other end. It is probably marked "2 x2MFD" or something like that. It is a double 2uF and has to be replaced with two 2uF caps. You are fine with the two 4uFs to make an 8, but the 8.2 would have been fine. Any value between +/- 20% is good.

Good luck

Kent

Hi Kent,

Thank you clarifying the (2) lead cap. I'm having an argument right now with Parts-Express regarding shipping so my order is still pending.

Aside from the fact that you spared me from making a mistake.

For that, I thank you much.

Regards,

Craig

PS: Boxes cleaned up nicely, I've caulked them heavily, DCR is excellent and well matched. I've removed about 10 layers of the black New England look stain and 40 years of grime. The grain is really going to pop on this pair.

Did the "20"s come with badges? I've got a cherry pair from a pair of '50s Model "6"s but they are awfully large. What was there originally?

Thanks again.

[JKent]

Did the "20"s come with badges? I've got a cherry pair from a pair of '50s Model "6"s but they are awfully large. What was there originally?

Thanks again.

Don't think so. Here is a page from "The Amazing Music Boxes of KLH" brochure

Kent

[Analogman]

Don't think so. Here is a page from "The Amazing Music Boxes of KLH" brochure

Kent

Thank you for the picture. I may use the badges I have; I'll decide after they're all back together.

Today I finished the boxes, this is what I've done:

Cleaned and refinished the veneer

Thoroughly caulked the interiors and terminal panels with 100% silicone

Caulked the groove entirely that is in the side and top panels where they meet the front baffle behind the grille, with acrylic

"Browned out" the front baffle with a light coat of enamel

Drilled and prepped terminal panels for "5-way" posts

Now all I need is the caps.

I am really into this little project. A Model 20 was the "in house" stereo system at my home town record store many years ago. I heard Abby Road and John Lennon's first solo album there on that system, as well as about a thousand other great records.

I remember well longing for that Model 20, and how much better it sounded than my 1965 Magnavox stereo portable, you know, where the lid is one of the speakers. Still it was better than my brother's all plastic G.E.

I will truly be taking a sweet, melancholy trip with these.

Thank you for all your help,

Craig

[bjornklh]

yeah ill vouch for these speakers. i found a pair about 12 years ago and have kept them ever since,indestructable, could use them as jackstands with them cranked and they wouldnt flinch. i dont know why one would want to do that, but still. very undervalued.

have incredibly soft clear sound. dont have crystal highs,or detail like the advents, but my 20s are still one of my favorite speakers, and at lower volumes with classical music and an old marantz, sound more real somehow then anything i own including my tivoli. (very similar sound somehow,mr kloss knew his stuff.) bought one set for 10 whole dollars, and found one orphan on the street in nyc, never give any of them up! good luck with the resto, caps for sure are necessary!

[Analogman]

Well, I've had them up and running since yesterday.

These are some DAMN FINE speakers, and I'm glad I did what I did.

They better a pair of B&W CDM-1SEs I once owned, I'm serious.

I only have (2) dislikes, both of which are really chicken shit and have nothing to do with anything that really matters:

1. The shape of the box, primarily it's shallow depth. Screams "all in one" like the crap Lloyds, Sound Design and others peddled through the '70s.

I know they were probably just copying the Model "20" "all in one", but the association with the crap is still there visually. Like I said, chicken shit complaint

2. The grilles will be for display only. Just put them on this morning for the first time. They KILL these bad boys. I was blown away by the quantity and quality of detail and space these old boxes put out. ALL of that disappeared with the grilles and things got a little smeary. I'll run them naked. Too much cloth; the outer decorative linen and then a layer of mesh underneath. They're original and in too nice a shape to re-cover with a more acoustically transparent material.

I think these are super nice by any standard, yesterday OR today. Clear and Clean. Amazing the voice on these little boxes. They've done a nice job on everything I've thrown at them. They even said the "N" Word yesterday, I played a little "50 Cent" for my bass articulation workout. The clarity was stunning.

Thanks for all your help and insight,

Craig

[bjornklh]

yeah ive noticed that with the grills. i take em off put em on depending on the day and how much i use them.

yeha they do pretty well with bassy music.

i think all those speakers listed were just copying, in the 70s evryone copyed klh's designs, and they were all pale comparisons.

like delco speakers in a cerial box.

yeah hold onto them though

[Analogman]

yeah ive noticed that with the grills. i take em off put em on depending on the day and how much i use them.

yeha they do pretty well with bassy music.

i think all those speakers listed were just copying, in the 70s evryone copyed klh's designs, and they were all pale comparisons.

like delco speakers in a cerial box.

yeah hold onto them though

I'll probably get myself into hot water for saying this .......BUT,

pound for pound I'm more impressed with this modest little 2-way than I am with my recently restored "AR"- 5s.

NOT saying "better than", no, not at all. Just "pound for pound". EVERYTHING they do, they do very well.

I've thrown every genre imaginable at these little "20"s at moderate to high volume and they're unflinching.

They have no sins of inclusion as far as I can hear, no sense of strain whatsoever.

They do a better job with crummy, modern highly compressed popular stuff than the "AR"s.

Less resolution maybe? I've always felt that resolution was a double edged sword (and not always a blessing) beyond a certain point.

The "KLH"s seem to have just the right balance you would want in a "work horse" type speaker.

Glad I found (re-discovered) the "New England Sound" and you guys.

This is a LOT of fun and very satisfying!

Regards,

Craig

[JKent]

I'm just curious--has anyone ever compared the 17 and 20 side by side? I believe they are identical, except for the impedance of the woofers. What do you think?

Kent

[bjornklh]

I'm just curious--has anyone ever compared the 17 and 20 side by side? I believe they are identical, except for the impedance of the woofers. What do you think?

Kent

well i may find out, may have found a set of 17s for not much and i will compare them. i think they should be the same..

also jkent i may need some guidance as im about to try to redo my 20s and 5s, bought all the caps, im poor now, but should be worth it.

thanks for the support. :>

[Analogman]

I don't know how they compare to "17"s but I do know the bass I am getting out of mine is mind blowing (perceived bass anyway).

Much more powerful than my "AR"-5s. These tiny little boxes will rattle the room at 12:00 o'clock.

There is a problem though. After about a week of trouble free operation, one of my boxes developed a noise, some sort of resonance. Thought I heard something amiss on heavy bass material and confirmed it with the Fender Bass track on a test CD.

Removed the offending woofer, inspected closely and found nothing obvious. Massaged the surround (it was lightly stuck to the frame in several places on the "backside" of the roll). Thought maybe this was possibly throwing the cone "off center". Nothing was loose or touching the cabinet with my crossover work.

Put it all back together, same noise but it did not seem as pronounced. As I mentioned elsewhere, I have these boxes sealed extremely well. The pressure developed on deep bass will actually flex the cabinet so you can feel it if you put your hand on the backside. I sealed my woofers and tweeters in the boxes using Permatex "Ultra Grey", a rigid RTV silicone. I chose this material as it will flow and seal like a very viscous caulk or epoxy, yet it will release from the metal frame with reasonable prying if the drivers(s) have to be removed. With the care I took assembling these speakers, I didn't think that would be the case, not for a long time. Not so.

I'm not 100% certain what I'm fighting here; a problem with the woofer or the box. At these low frequencies it's hard to pinpoint absolutely. When I first removed the suspect driver I ran the test material through it "free air" and it did seem to make unwanted noise but not as severely. Obviously, I could not run the test material at as high SPLs with the driver unloaded.

This noise problem is most pronounced during the decay of heavy bass notes. The woofer handles the actual "striking" of the note cleanly. Initially I suspected an air leak in the woofer seal, but after removing and re-installing, I am satisfied that this is not the case.

When I started this project and first removed the drivers I noted a fine line of corrosion or light rust at the joint where the motor and frame join. I am thinking it is possible I am getting some flexing here under high pressures. I just don't know. This is VERY frustrating.

I have removed the woofer for a second time and have thoroughly inspected it in good light. I can see no flaws or defects, yet I still suffer this condition. Everything appears tight and there is ZERO voice coil rub. Weak spider perhaps? Today I plan to "dope it up". I'm going to apply some fresh epoxy to the former/cone neck joint, apply "JB" Weld to the moter/basket joint and treat the spider (the outer edges) with a little cloth surround sealer. The frustrating thing is, is if the problem goes away I will never know with certainty which link specifically was the weakest.

The other box continues to perform flawlessly and plays hard, deep, clean and clear bass without objection.

If anyone has experienced a similar episode please share.

Regards,

Craig

[Analogman]

I have also been wondering if the tweeters used on these "KLH"s are "open" in the back. and subject to direct pressure. With everything on the baffle, and my noise coming off the baffle, maybe there is a problem there? Any issues/experiences with cabinet pressures "blowing" out these tweeters?

Craig