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KLH 12's - another hole in my KLH collection filled . .

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Carlspeak    0

I just upgraded a pair of 12's Contour XO's. Didn't go over the top like Kent did with the Auricaps. It was just a basic upgrade that was badly needed after checking the ESR's and uF's on those brown jobs.

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GD70    0
On 1/2/2008 at 0:57 PM, JKent said:

Hi Vern

Thank you for the compliments and your comments.

Yes--I had not noticed the wafers on the switches, but there is a difference between my all-npe xover and the mylar/npe one I just finished.

Also did not notice the penciled SN on the plywood, but now that you mentioned it, the xovers that have the "brown wafer" switches are marked in pencil "#240" and "#263." I did not see numbers on the "white wafer switch" plywood. There was a date, hard to read (Sept something) and I see I covered it with Goop to glue down the caps :(

Interesting note on CR's take on the Twelves vs AR3a's. I don't think the Twelves get the respect they deserve! They are essentially identical to the well-

regarded Fives, but with bigger cabinets so they go deeper. That asset is also a liability.

I bought mine for $100 with local pickup, and that included a KLH Eighteen tuner and an old speaker selector switch! Only problems with the Twelves were:

Missing 3 knobs, terrible sound because of bad caps, a few minor nicks and scratches, tired-looking grille cloth.

They now sound great with the new caps. I'm in the process of refinishing the cabinets and patching the veneer in a couple of places. Not sure what to do about the grille cloth. I have the metal logos but have not reinstalled them yet.

Your comments about the paucity of KLHs in your neck of the woods is interesting. Of course, in New England they were very common. I notice a lot of Dynaco speakers on ebay come from Canada. Guess Dynaco did a better jo of marketing up North!

Yes--the speakers are sometimes sold without the crossovers. Hard to imagine, unless buyers are opting for external electronic crossovers. Expensive, but

probably nice. As I mentioned, I plan to sell one pair of crossovers (don't need two!) so I hope I can recoup the cost of the caps and knobs. Originally I had bought some nice inexpensive retro-style knobs in Rat Shack (shown in one of my previous posts), since 3 of the originals were missing. But the second pair had (only) 3 original knobs, so now I have one complete set!

Could have used that schematic! Maybe then I would have bought the right number (and value) of caps! :)

Here's a photo of one Twelve. Not finished yet. The xover was moved for the photo but is normally attached to the back with Velcro. More work to do on the finish. New cloth needed. Reinstall logos. Too bad these are in the hall OUTSIDE my rec room! :(

Kent

post-101828-1199383018.jpg

They look great! The cloth is in pretty good condition, personally, I'd leave it as is. The veneer looks fantastic too!

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GD70    0
On 1/2/2008 at 0:57 PM, JKent said:

Hi Vern

Thank you for the compliments and your comments.

Yes--I had not noticed the wafers on the switches, but there is a difference between my all-npe xover and the mylar/npe one I just finished.

Also did not notice the penciled SN on the plywood, but now that you mentioned it, the xovers that have the "brown wafer" switches are marked in pencil "#240" and "#263." I did not see numbers on the "white wafer switch" plywood. There was a date, hard to read (Sept something) and I see I covered it with Goop to glue down the caps :(

Interesting note on CR's take on the Twelves vs AR3a's. I don't think the Twelves get the respect they deserve! They are essentially identical to the well-

regarded Fives, but with bigger cabinets so they go deeper. That asset is also a liability.

I bought mine for $100 with local pickup, and that included a KLH Eighteen tuner and an old speaker selector switch! Only problems with the Twelves were:

Missing 3 knobs, terrible sound because of bad caps, a few minor nicks and scratches, tired-looking grille cloth.

They now sound great with the new caps. I'm in the process of refinishing the cabinets and patching the veneer in a couple of places. Not sure what to do about the grille cloth. I have the metal logos but have not reinstalled them yet.

Your comments about the paucity of KLHs in your neck of the woods is interesting. Of course, in New England they were very common. I notice a lot of Dynaco speakers on ebay come from Canada. Guess Dynaco did a better jo of marketing up North!

Yes--the speakers are sometimes sold without the crossovers. Hard to imagine, unless buyers are opting for external electronic crossovers. Expensive, but

probably nice. As I mentioned, I plan to sell one pair of crossovers (don't need two!) so I hope I can recoup the cost of the caps and knobs. Originally I had bought some nice inexpensive retro-style knobs in Rat Shack (shown in one of my previous posts), since 3 of the originals were missing. But the second pair had (only) 3 original knobs, so now I have one complete set!

Could have used that schematic! Maybe then I would have bought the right number (and value) of caps! :)

Here's a photo of one Twelve. Not finished yet. The xover was moved for the photo but is normally attached to the back with Velcro. More work to do on the finish. New cloth needed. Reinstall logos. Too bad these are in the hall OUTSIDE my rec room! :(

Kent

post-101828-1199383018.jpg

They look great! The cloth is in pretty good condition, personally, I'd leave it as is. The veneer looks fantastic too!

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JKent    0
15 hours ago, GD70 said:

They look great! The cloth is in pretty good condition, personally, I'd leave it as is. The veneer looks fantastic too!

Thanks. That was 8 years ago. I really like them but had no room so I sold them to a friend of a friend who lives in town (at a slight loss I'm sure). He did ask me to replace the cloth so I re-did them in the excellent 18-count linen from 1-2-3 Stitch. Don't have a photo of the speakers with the new cloth but here are the grilles. I suspect the linen is better than the double-layer boucle + black scrim.

A couple of years ago the speakers suffered a blown tweeter and a woofer problem. I replaced the tweet and sent it to Bill LeGall for expert repair. Also treated both woofer surrounds with Roy's butyl sealant and added fuses. I see the current owner from time to time and he (and his wife) are still happy with them.

finished linen_edited-1.jpg

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ReeferDude    0

Hi all, joined this place when I picked up my Model Twelves.  Nice place round here.

 

I took the plunge and did my own set of contour boxes on my newly acquired pair of 12s.  Truth be told, it was my first attempt at something more that single cap speakers.  I think I did ok.  The sound fantastic on my Fisher 400.  What an excellent speaker.  I had been running EPI M180s with new caps and fresh surrounds.  The KLH are superior across the board....and the EPI are no slouch!

Thanks to @JKent for posting something so thorough.  Much appreciated!

 

 

I was on a role so I capped a Silvertone 9315 amp too.first amp ever too.   Worked...was a good day with the iron, especially for a rookie.

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JKent    0
21 minutes ago, amarjr1 said:

Looking for a good tech to recap model 12 crossovers. any recommendations? picked up cap and resistors but cant find time.

PM me if you want me to do them.

-Kent

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JKent    0

amarjr1 did contact me, so here's another KLH Model Twelve re-cap/re-'sistor. The first box had some problems. As members here may know, I always take out the 5w resistors and replace them with 10w minimum. Well, the first box I looked at had two THREE watt resistors in there!

amarjr1 had supplied the electrolytic capacitors and nice Mills 12w resistors. I needed a couple more than those supplied so there are 2 Vishay 10w resistors (the black ones) and one generic 15w (the white one). Those are what I had on hand.

The old capacitors were shot! I tested them all and here's what I found:

  • 50uF  tested 111uF
  • 50uF  tested 133uF
  • 2 x 4uF tested 0.002 & 0.001uF
  • 2 x 4uF tested 6.8uF & 7.3uF
  • 2 x 2uF tested 0.2 & 0.2uF
  • 3uF tested 0.27uF
  • 2 x 4uF tested 5.92 & 5.94uF

Here's a photo of a finished box and an original

New & old.jpg

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JKent    0

Another pair complete. Caps in the 2nd box were as bad as the first: 

  • 50uF tested 121.8uF
  • 50uF tested 112.4
  • 2x4uF tested 0.464 & 0.228
  • 2x4uF tested 0.002 & 0.001
  • 2.4uF tested 0.002 & 0.001
  • 2x2uF tested 0.072 & 0.10
  • 3uF tested 3.63 (this was the ONLY cap of the lot that was anywhere near spec!)

Don't have my Twelves any more so I can't test the contour boxes, so fingers crossed ;)

Here are before & after pics (2 before, 3 after). The cabinets were good with just a couple of chips and some paint marks. One faceplate had a couple of dings. The body & fender work is "OK"--not perfect. I stripped off the old lacquer and gave them a couple shots of new.

resize before 3.jpg

resized before 7.jpg

resized after 2.jpg

resized after 6.jpg

resized xos.jpg

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ra.ra    0

Nice work by JKent, as always.

Despite the fact that this multi-level contour crossover concept did not particularly catch fire in the 60's-70's hi-fi era, I find myself somewhat enamored with this squarish floor-standing speaker model and its separate control device. My understanding of the KLH Twelve is that it is a three-way speaker product (including two mids, totaling four drivers), with crossover frequencies at 500Hz and 4000Hz.

I am curious about a few things. Regarding the control box casing, is this a thin metal shell that is covered in faux vinyl or is it a thin walnut veneered plywood? And the control dials: do they just rotate about 90 degrees between + and -, with the dot representing a hypothetical "flat" response? And the rear screw terminals: I assume the two-screw terminal is the amplifier connection, but how is the four screw terminal connected to the driver cabinet?

The circuitry of this device sort of bewilders me, and my questions are based on the labeled frequencies at each dial on the front panel. With KLH literature stated x-o frequencies at 500 and 4000, is this an accurate understanding of the four dials: left dial controls woofer and very lowest Hz of the mids; second dial controls lower Hz of mid; third dial controls higher Hz of mid and lowest Hz of tweeter; and right dial controls the highest squeaks and brushes of strings and cymbals?       

Great pics from ReeferDude, too, and welcome aboard to CSP. But....what exactly is a reefer? Is it like a capacitor?...or a resistor?....or an inductor?...or a potentiometer? :rolleyes:

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JKent    0

Yeh--I always liked the Twelve. Just didn't have room for them.

  • The cover of the box is thin plywood with walnut veneer. I wish these posts were still numbered but if you go back 1 page you should see pics of the covers.
  • Yes-- +, - and flat
  • Yes--the 2 screws are the connection to the amp. The 4 color-coded screws are for connecting a 4-wire cable to the speaker: common and woofer, mid, tweeter. KLH supplied a pair of short cables for those who want to mount the contour box on the back of the speaker, and a long (40') cable so you can control the contour from your listening position.
  • Not sure about the crossover points but that sounds right.

I have some lit that's too big to post here--watch your email.

-Kent

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ra.ra    0

Thanks for sending those documents - - - I understand a little better now. And yes, I finally do see the pic of the wood enclosure. That's a rather unique device, and with that unusual 4-wire connecting cable. The Hirsch review was a little difficult to read, but it was interesting that both the review and the product instructions discussed making initial control settings while listening to FM inter-station hiss, and later making subsequent adjustments listening to familiar musical sources.

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