KLH Model Twenty Speakers Paired With KLH Model 24 Receiver?

[Swilson 1974]

I have nice pair of model twenty KLH speakers and I was wondering if I could pair it with a later model 24 receiver? The output for the twenty four is rated at 8ohms but the model twenty speakers are 4ohms. I'm not an expert on this and but I know in some cases you drive a 4ohm speaker even if the power rating is for 8ohms. Any help? I'm not sure about this ohm stuff...

I found this link but I can't make heads or tails of it: http://www.aphenos.net/electronics/speakers/klh/all_klh.htm

 

[nnicola]

I don’t see any other answers, so I’l give it a shot.

As far as I know, the amplifier in the KLH Model Twenty and Model Twenty Four music systems were rated at 30 wpc IHF, so it’s a good bet they are the same amp. (BTW, IHF is different than the RMS wattage rating in use today. 30 watts IHF is probably closer to 10-15 watts RMS.) I’m not sure about the Model Twenty Six music system, but KLH tended to repackage their amplifiers for use in all their music systems. I'm reasonably certain that the amp in the Model Twenty music system, the one designed to power the Model Twenty, 4 ohm speakers, is pretty much the same as the amp in the Model Twenty Six system.

I owned a set of Model Twenty 4 ohm speakers from a Model Twenty music system “back in the day”. It was my main speaker set from 1971 until about 1980. I used all manner of amplifiers and receivers to power the Model Twenty’s and never had a problem. Most amplifiers and receivers can power a 4 ohm load without a problem, and I don’t think the KLH amplifiers are an exception. The only thing you cannot do with a 4 ohm speaker is pair it with another speaker set and try to drive two sets of speakers at the same time. The load on the amp then drops to below 4 ohms, and almost all amps will have a problem with that.

Bottom line: You should not have a problem driving the Model Twenty speakers with the Twenty Six amplifier if the amplifier is up to specs. That’s not a written guarantee, only because you’re working with an amplifier that is probably just under 50 years old, and it could be significantly under its design specifications. Try plugging the speakers into the amp with RCA plugs connected to some speaker wire. Listen at low volume and try to hear if there is any distortion. Slowly increase the volume and carefully listen until you are at a moderately high volume. If you are concerned about the condition of the amp, bring it to a tech for a once over before trying the Model Twenty speakers.

BTW, have you changed the capacitors in the speakers and sealed the cloth woofers? KLH capacitors are notorious for going bad over time, and if the woofers are not sealed the bass performance of the speaker will be seriously compromised. If you need a sealer, let me know and I can recommend the only sealer you should use.

Good luck, and let every one know how you make out.

 

[Swilson 1974]

Hi Nnicola. Thanks for the response! I see a lot of refurbished Model Twenty Fours online and guy upstate has one that looks like he did a great job on. I feel fairly certain after your response that I should be in good shape. My twenties have not been re capped and I have not sealed the woofers. I am interested. BTW I'm in Elizabeth Nj so if can recommend any places to have the speakers recapped let me know. Or is recapping something I could do myself? I have a massive record collection but I'm new to all this audio stuff.

 

[RTally]

Hi Nnicola. Thanks for the response! I see a lot of refurbished Model Twenty Fours online and guy upstate has one that looks like he did a great job on. I feel fairly certain after your response that I should be in good shape. My twenties have not been re capped and I have not sealed the woofers. I am interested. BTW I'm in Elizabeth Nj so if can recommend any places to have the speakers recapped let me know. Or is recapping something I could do myself? I have a massive record collection but I'm new to all this audio stuff.

You can recap the speakers yourself if you are comfortable using a soldering iron. The KLH crossover has soldered connections to the switch and terminals and wire nuts everywhere else. The crossover is the same as for the KLH 17.

I don't have pics of the before, but here are pics of my 20s after recapping. I replaced the RCA connector with 5-way binding posts and used Dayton poly caps from Parts Express. I hot glued the caps in place.

You can message RoyC (the maker) here on AK or check out vintage-ar for the butyl compound for the surrounds. Use no substitutes if you value your speakers.

 

[nnicola]

Very good advice from RTally!

Don’t use anything but the product sold by RoyC on the speaker surrounds. There are threads on this site and other sites about using different types of caulk or other homemade concoctions. Don’t be tempted to use them. RoyC’s goo is formulated like the original KLH product and it won’t damage your speakers.

 

[gadget73]

A dozen honest watts sounds about right for a KLH 24. If I remember right, those things use germanium output transistors so you might want to have a look at what speakers they paired with originally to confirm the impedance is the same as the 20 speakers. I had a 24 receiver at one point, but never had the matching KLH speaks, and honestly know next to nothing about their offerings.

reason I say this, germanium transistors aren't exactly too available these days so if you nuke them it will be a little bit of a headache to replace. Honestly that thing probably wants a refresh anyway. I had several bad caps in mine that completely killed the FM. I patched it up so it would work as a shop stereo, and eventually gave it to someone for the cost of the needle I had put on it. I'm sure it would have worked a lot better with a rehab. Not exactly a fun thing to work on either, they really packed those cases tight. Everything is arranged around the record changer guts and pretty much just stuffed wherever it fits.

 

[hornbostel]

Recapping KLH 20’s is simple. You don’t need a soldering iron. You can use wire nuts. Here are pics of the original crossover. It’s a hodgepodge of wires. But actually pretty simple. Just cut the wires as close to the old caps as possible. Then strip the wire a bit. I used super cheap Dayton electrolytic caps. No need IMO to spend big on caps for these speakers. I Wired caps in place with wire nuts. Easy. Of course treated cloth surrounds with Roy C goo. Great speakers. Plus they look fantastic.

 

[Shanebow]

This looks like a good thread for me to solicit a couple of opinions and I'm sitting in an airport in Quebec for the next hour so here goes. I just bought a KLH Twenty Four system without the speakers for $35 right when I went on vacation because I like automatic record changers, he said that part worked, I thought it looked cool, and the brand has a good rep so I figured they used a half way decent Garrard, like an AT6 or something. The guy said it needed recapped but I didn't care at the time because after checking with a couple of redditors it sounded like even a novice like me could run the tt output into the aux connection on one of my vintage receivers and I had no interest in the FM part. But of course lo and behold like the day after I leave what shows up on marketplace but a pair of KLH Twenty Four Series II speakers at $45 list. So now do I stick with plan A and just convert and connect the tt to my current system or do I pay for the recap because I don't think I can do that and buy the speakers, which supposedly work as they should? For what it's worth I currently run a Dual 1219 tt through a Pioneer SX-636 with some DCM Time Windows and an ELAC Miracord 50H tt through a Sansui 2000A with some AR-4x speakers. If I don't try to restore the whole 24 system, I will probably try connecting the KLH tt to a pair of Klipsch The Sevens. Pretty nice powered bookshelves but I have a couple other options. Any thoughts are appreciated. Thanks

 

[gadget73]

I think its closer to the 3000, but the mechanism is the same as the AT6 or AT60. There are a bunch in that family that mostly differed in paint schemes and tonearms. The specific hiccup with the KLH one is that it needs a specific variant of a Pickering V15 to mount. The cartridge probably is fine, you just need a stylus for it. Stock I think it wants a D7C, the 3-7 gram conical 0.7 mil but you may be able to run a slightly better one depending on the tracking weight. Its adjustable with a screw at the back of the arm but I don't know exactly how much range you get. Likely isn't going to run well under about 2 grams though.

If that changer hasn't been refreshed, trust me it needs it. The grease gets sticky and they act funny even if it mostly works. Its not hard if you're somewhat mechanically inclined, its just tedious and there are a lot of pieces that have to go in a specific location. Take lots of pictures, its not that bad. Beware the loose bearings under the platter. If you don't collect the balls before turning it over, they will scatter.

My 2 cents, I'd run this as it was meant to be, a complete unit. If you want a changer to go with your other rig, get one that was intended to be stand-alone and uses a 1/2" mount cartridge to give you more options. In Garrard land, if you're after the small format changer I'd go AT6, AT60, or SL65. Those are the top of the range, though an AT50 or SL55 are fine too. Nearly the same, but the counterweight is not adjustable. The SL models have a slightly better motor. The 2 pole used in this specific one vibrates and you'll get a steady mechanical hum through the speakers. I was never able to eliminate that from my 24, and I could feel it vibrating from the motor. Never had that issue with an AT6 or AT60 with the 4 pole motor.

 

[Shanebow]

Well that's a bit more involved than I was hoping for but it sounds doable if I'm patient, deliberate and methodical. Especially since the money isn't life impacting. Thanks for taking the time to help inform me.

 

[RunOutGroove]

All that brings me back... I don't tend to have too much sentimentality for gear, but the KLH compact thing may be an exception. That's what my family had and that's what I played all of the records that got me into this whole music thing on. Those things where everywhere, at least within my family's circle of middle class/upper middle class friends. I think that these things were well reviewed in Consumer Reports which of course far from an audio mag, was pretty influential back in the day and may have been the reason why my mom and lots of other folks bought that thing over anything else.

The main unit thing is long gone (and I don't have the space nor the want to set something like that up anyway), though I do have the speakers, which I used as extras in another room with my Marantz 2270 for a while some years back. I don't remember them sounding terrible, but a little bit flat, which might have had something to do with the fact that parts needed replacing or that they're 4 ohm, which I didn't realize until now. I know that 4 ohm isn't the best match for the Marantz. Currently, I have three sets of speakers hooked up to it which are all either 6 or 8 ohm and I rarely run them together, though when I do, I use a speaker protection switch built into my speaker switcher box.

Anyway, there's something cool about that old KLH gear... at the very least aesthetically, it's top notch! The cabinetry on those things is very nice. I wonder if there are recopies for modding these things with more modern drivers and crossover parts? That might be a nice project. I'd love to get some use out of those cabinets for sure.

 

[Shanebow]

Thanks for the response. I'm of a certain age too and what I thought was going to be a nice simple little turntable conversion has now taken on a life of its own with the appearance of those speakers to go with it. My nature is to want to do the whole thing now but I don't think that my desire matches my ability or desire so I may just go with the realistic expectations and stick with my original plan to convert the tt portion, even though it might leave a small hole in my heart.