9s - what to drive them with

[Guest Bret]

I didn't get a response to this question I asked in a different thread, so I'm trying it again hoping to avoid a disaster of my own creation.

I have and elderly aunt. She has a pair of KLH-9 speakers in her garage. Before the humid Mississippi summer is upon us I would like to get them in her living-room (or somewhere indoors). The best/easiest way for me to do this is to set them up so that she can listen to them.

I would like some idea of a reasonable amount of power for them.

Any other pointers anyone can offer about things to check, or things I "ought to do" as ways of preserving these would be appreciated.

Bret

[Guest palomar]

Bret,

I have no experience with these or any electrostatic speakers, so I can only share a couple of things that I have heard about them. I don't know whether they apply to these particular speakers or not.

In some cases, electrostatics can be permanently damaged by even a short overload. I don't know the exact failure mechanism, but apparently once this happens, they will distort (I'm not sure what kind of distortion it is) at much lower volumes than before. So unless you hear differently from a more knowledgeable user, I'd be careful about trying to play them too loudly with a really large amp.

The other thing I've heard is that just a important as amplifier power, is amplifier stability. Maybe it's not a problem with modern amps, but because of the very high reactance of electrostatic speakers, they tend to be difficult loads for some amps to handle. I believe the end result is that the amp starts distorting or ringing well below what you expect based on its power rating.

These speakers are considered by some to still be some of the most musical speakers ever made, so I would most definitely do your best to preserve them.

Good luck.

Gary

[administrator]

How would a power conditioner come into play here? I've never owned electrostatics, but listened to a pair up at Intelligent Audio Systems and could see why you would want to be careful. I noticed recently even the $99 battery back-up system I bought for the website purports to condition input power with certain problematic characteristics.

If bad power goes into the amp, can bad power hit the electrostatics? Or do most amps account for this? I guess fuses would be the most basic way to account for problems, but is that sufficient?

Mark

[soundminded]

These panels are notoriously inefficient. They also present a highly capacitive load to amplifiers. Marginal amplifiers can be damaged or at the very least will be ineffictive. I'd choose a fairly high power solid state amplifier with about 100 wpc or more and rated as stable with all passive loads. A Hafler is probably a good choice. There are certainly many others.

BTW, for some reason, most electrostatic speakers of this age have deteriorated badly. I have no idea how to check them to see if they are still operable. I'd use caution at first until you determine that they are OK. Perhaps someone from the service department of a company which specializes in manufacture of electrostatic loudspeakers like Martin Logan could give you some practical advice.

[soundminded]

The main danger to these loudspeakers are high voltage spikes. Amplifiers of the quality needed to satisfactorily drive these speakers should have well filtered well regulated power supplies. Of equally great concern would be the high voltage power supply necessary to bias the plates. I think it ran at about 8000 volts DC. As I recall there were reliability issues with this particular model. Components for this type of power supply weren't nearly as reliable 40 odd years ago as they are today. At the very least I'd use a plug in MOV type surge arrestor on the power supply input. These are the cheapest protection you can get. Overvoltage due to spikes can not only damage the power supply but the panels as well by exceeding their dielectric breakdown voltage.

Amplifiers available in the early 1960s suitable for this speaker were few and far between. They were among the most powerful and expensive of their day. Marantz 8 and 9, McIntosh Mc275, Dynaco MK III, HK Citation were among the select. Even Dynaco Stereo 70 didn't have the guts I think. Fishers and Scotts were practically out of the question. People who could afford these speakers usually had the financial resources to buy those amplifiers and the space in their homes to accomodate them. They need to be about 3 to 6 feet away from a back wall to make use of the rear radiation which given their inefficiency and limited maximum acoustic power output is not an option.

[Guest Bret]

>Components for this type of power supply weren't nearly as reliable 40 odd years ago as they are today.<

Would you go hog-wild and replace all the components in the power supply? I don't even know how daunting a task that might be. I've seen the power supplies open, but that was a very, very long time ago.

If it is anything like a Janszen, it isn't too complicated.

I don't have a Variac, but I could put them on a dimmer and bring the voltage up slowly if you think there is any merit in that (waiting for an old cap to go "boom").

Bret

[soundminded]

If I were going to restore these power supplies (I've never seen one open and don't know anything about them) I'd look to replace probably the electrolytic capacitors and the rectifiers. I'd try to leave any transformers and inductors alone unless I knew they were bad. Be careful, the capacitors may be oil filled, even with PCB. After all these years, they may be leaky. They might have to be disposed of as hazardous waste. Be very careful of clearances with the replacement parts. HV can cause a spark to jump at these voltages over gaps that are perfectly safe at low voltages. Check all insulators for cracks and replace as necessary. Be certain all components are clean and free of dirt and grease. If present, these can cause "tracking" where they will conduct right through the grease on insulated parts. Be sure to discharge any and all capacitors before working on this power supply after each time is is connected even if it's been off for a while. They can hold a residual charge of thousands of volts and are potentially very dangerous. If you need to use any kind of potting compound or insulating tape on the high voltage side, be sure it is approved for that use. Sometimes glass tape is used.

Another possibility is to find new replacement power supplies of comparable voltage and current. You might talk to the service departments of companies which manufacture electrostatic loudspeakers like Martin Logan.

Be very careful and Good luck.

[Guest Bret]

>Be very careful and Good luck.<

It's not like I'm trying to make you "responsible" or anything, but I was wondering if you knew of a good way, or a good internet site, or a good something, that could lead me to a safe way to drain caps that are already in-circuit. I've seen a knife-switch layout where you clip (how much clip is enough? Jumper cables?) leads to both sides, have a load (how much is enough?) and a switch. Put on a hard-hat, safety goggles, stand in the next room and throw the switch. . . well, that's fine and all, except you eventually have to be brave enough to stick something across the leads to see if you've bled it.

Or should I just try to find someone who does this stuff and let them get knocked across the room? I've only had that experience once, but that was quite enough, thank you. (television set I was in when I was about 13)

Don't you dare say, "That explains a lot."

Bret

[soundminded]

Actually, I'd say talk to anyone who works in a shop which repairs television sets. A service technician. Why not contact fluke or someone who sells measuring equipment. They sell probes for high voltage and may have hardware to saftely discharge capacitors. Anyone who works for a utility such as an electrician who works on high tension lines although you will have to explain that your application if for high voltage electronic power supplies. What the equpment consists of will be some sort of clip to attach to ground and an insulated probe to touch to the HV anode terminal. The charge will dissipate to ground through an internal resistor in the probe. There also may often be a light to let you know when it is safe (or not safe.) You'll have to do a little digging yourself. BTW, from 1000 to 15,000 volts is technically "medium voltage" to an electrician even if an electronics tech would call it high voltage. People working with this type of equipment whether for a utility or electronic technicins will usually be happy to talk to you about it in the interest of safety.

[Guest Bret]

Good idea. I really hadn't thought about a utility-guy. Figured the electronics techs would figure knowing that part of what justifies paying them.

If these were mine, I'd take them somewhere, but they aren't, so cheap's the word.

Thanks

Bret

[Andy]

Anyone know the approximate number of these speakers that were produced, at $1,140. it must not have been many. It's been stated that Janszen radiator in these speakers were produced by Neshaminy............who was Neshaminy? Also, kloss stated that Arthur Janszen joined KLH as a fourth member in the early 60s, how long did he stay with the company and did he work on any other speakers?

[dynaco_dan]

Hi Bret

Here I am dragging up the rear July 24th and see your posting.

First, what happened to the 9's?

Are they still untested and in the garage?

My first suggestion would have been to move them into the house and allow at least a week to climatize themselves.

I was fortunate to have seen and heard one pair connected to a PAS3x, Dyna 70, and Thorens TD124 w/SME arm/V15 type 2 cartridge.

We were curious why an osciliscope was also connected to the output of the amp.

The dealer said, so he wouldn't blow the 9's up.

We knew it was so he could keep the level low enough so that if the amp was clipping he could keep the level a little lower.

How did they sound.

Fantastic!

You had to sit just in the sweet spot and with the moderate volume level of even this lowly amp was enough to make you want to mortgage your home.

With a double pair of 9's, a Crown DC300a or similar was thought to be compatible for load versus power output.

Like I say, the Dyna ST 70 was enjoyable. (35 w/ch )

Hope to hear what has transpired since your last entry.

Good luck.

Vern

>I didn't get a response to this question I asked in a

>different thread, so I'm trying it again hoping to avoid a

>disaster of my own creation.

>

>I have and elderly aunt. She has a pair of KLH-9 speakers in

>her garage. Before the humid Mississippi summer is upon us I

>would like to get them in her living-room (or somewhere

>indoors). The best/easiest way for me to do this is to set

>them up so that she can listen to them.

>

>I would like some idea of a reasonable amount of power for

>them.

>

>Any other pointers anyone can offer about things to check, or

>things I "ought to do" as ways of preserving these would be

>appreciated.

>

>Bret

[Guest Bret]

>Hope to hear what has transpired since your last entry.<

Okay, Vern, here it is:

I had a friend who was a tech, taught me a lot (most of which I've forgotten in the intervening 27 years). Lent me equipment. Was a good guy, but I haven't talked to him in about six-seven years (kids will suck all your spare time and we both had several).

So I called him to see if I could get him to look at these 9s and join me in a little "stereo play" and getting reacquainted. His wife called me back. He died of a brain tumor a year and a half ago. He was 51.

This hit me *very* hard for reasons I'd rather not get into in the open forum, but this isn't the first loss like this I've experienced lately.

Eventually I managed to say, "Life goes on," and I called my repair shop that I've been using since the 70s. It's closed. So I looked for their competitor in the Yellow Pages. They are gone. So I looked for someone else; TV, VCR guys. I called two. Neither would touch these speakers.

These have not been connected and used at least since my uncle died and I don't know how long before that as he was ill for quite a while before he suddenly died. These were his basement speakers; he'd listen while tinkering. It's conceivable they haven't had power to them in 12 years. So I'm chicken to just go over and hook them up.

That being the case, I haven't made the trek to the aunt's house to move them from the garage, so they've spent a Mississippi summer in her humid garage as yet another insult.

Lately I'm finding there are a lot of things I seem to be able to do nothing about.

If I ever get this situation resolved (and this situation has to stand in line with a host of other situations I have to deal with) I will come back and post.

BTW - the aunt told me that she would not sell them as she is under the impression that my uncle told her they were the best speakers ever made. I seriously, seriously doubt he ever said that, but that's what she remembers, so just because she can no longer hear the doorbell when it rings and wouldn't hear the difference in a KLH-9 and an intercom speaker, that doesn't mean she doesn't want to keep the "best" even if it's in her garage, unused. She's 80 this month.

Bret

[dynaco_dan]

Hi again Bret

Sorry for your losses, Bret.

Now another rattle, rattle, rattle session.

We all have pain at times but this is one hobby that we can all still enjoy by ourselves while we reflect.

First if we go back to the origin of the KLH Nines.

My understanding is they are a joint project of KLH and Arthur Janzsen, the inventor of these and Janzsen products.

When AR came out with the AR-1 they used another manufacturers 8" cone tweeter that was, in it's day, considered quite acceptable.

Someone saw an opportunity of using a Janzsen 130 electrostatic speaker with the woofer only section of the AR-1.

This add-on mid range tweeter combination was a tremendous improvement.

This was never sold by AR as a set and Janzsen created there own woofer which was ok, but not of the AR-1 calibre.

Janzsen panels were used in the KLH Nines without a subwoofer.

At the time JGH of Steorophile fame, if I remember correctly, thought they were, superb, to put it mildly.

There was it's faults, and weaknesses like any other speaker system.

We won't get into cables and connectors here but finding an amp suitable back then was a chore.

An acceptable solid state amp was the Crown DC300A.

They are still available on eBay for example at a reasonable price.

I think the Dynaco Stereo 70 was another lower powered tube type amp. that was acceptable.

Some defficiencies could be lessened by adding another pair of panels or 2 panels for each stereo channel.

Dispersion was restricted to a sweet spot. Power handling was somewhat limited.

They were crystal clear in the mids but the bass and the treble was lower in energy with just the 2 panels.

For your uncle to have said, "they were the best speakers made back then," was probably, so close to the truth, I don't feel anyone on this site would argue with that statement.

He had great taste and probably an empty fridge also. lol

Because they haven't been used for a while I would suggest at least a week getting climatized indoors.

I'm sure there will be some other suggestions such as checking out the power supply etc. forthcoming.

Looking forward to more feedback from you, Bret.

Vern

>>Hope to hear what has transpired since your last entry.<

>

>Okay, Vern, here it is:

>

>I had a friend who was a tech, taught me a lot (most of which

>I've forgotten in the intervening 27 years). Lent me

>equipment. Was a good guy, but I haven't talked to him in

>about six-seven years (kids will suck all your spare time and

>we both had several).

>

>So I called him to see if I could get him to look at these 9s

>and join me in a little "stereo play" and getting

>reacquainted. His wife called me back. He died of a brain

>tumor a year and a half ago. He was 51.

>

>This hit me *very* hard for reasons I'd rather not get into in

>the open forum, but this isn't the first loss like this I've

>experienced lately.

>

>Eventually I managed to say, "Life goes on," and I called my

>repair shop that I've been using since the 70s. It's closed.

>So I looked for their competitor in the Yellow Pages. They

>are gone. So I looked for someone else; TV, VCR guys. I

>called two. Neither would touch these speakers.

>

>These have not been connected and used at least since my uncle

>died and I don't know how long before that as he was ill for

>quite a while before he suddenly died. These were his

>basement speakers; he'd listen while tinkering. It's

>conceivable they haven't had power to them in 12 years. So

>I'm chicken to just go over and hook them up.

>

>That being the case, I haven't made the trek to the aunt's

>house to move them from the garage, so they've spent a

>Mississippi summer in her humid garage as yet another insult.

>

>Lately I'm finding there are a lot of things I seem to be able

>to do nothing about.

>

>If I ever get this situation resolved (and this situation has

>to stand in line with a host of other situations I have to

>deal with) I will come back and post.

>

>BTW - the aunt told me that she would not sell them as she is

>under the impression that my uncle told her they were the best

>speakers ever made. I seriously, seriously doubt he ever said

>that, but that's what she remembers, so just because she can

>no longer hear the doorbell when it rings and wouldn't hear

>the difference in a KLH-9 and an intercom speaker, that

>doesn't mean she doesn't want to keep the "best" even if it's

>in her garage, unused. She's 80 this month.

>

>Bret

[dynaco_dan]

Hi again Bret

Of course I think of something else after the fact.

I believe I read in an old, "The Audio Amateur" issue that there was a weakness in the power supply.

This may have been for the KLH Nines or the Janzsen 130's or both.

Printout or make a note of this as it might be important down the road.

The fix was soldering a series ( 6 or 8 ) of diodes together.

The article went on to tell why and my guess was, diode breakdown.

Maybe they were poor quality or whatever.

Good luck again, Bret.

Vern

[Guest Bret]

>He had great taste and probably an empty fridge also.<

Oh, he was world's best bargain-hunter. He bought the LSTs from a "fire sale store" (liquidated failed stores' inventory) for less than the price of a pair of 3a's. I was there and he just made the store an offer well below what the price tag said - and they took it. We had to go back and pick them up in another car because there wasn't room in the '71 VW fastback we were in (the one with two trunks). That was about 1974. There wasn't even any way to hear them, so it was a gamble that worked-out well.

The KLH-9s didn't show-up at his place until the mid 80s, and they didn't work when he got them, so you can bet he found them at an estate sale or something. He was good at that. He'd buy non-working expensive stuff for $15.00 and spend a couple of hours and $.50 fixing it. He had stacks and stacks of used electronics. Some of it just for the heck of it. I was recently reminded of his having a huge CRT cabinet that was video "RAM" from whatever year that was popular in mainframes - and he had it working, or at least displaying something (I think I remember it was just a string of characters).

His "listening room" had AR-9LS's in it, but most of his time was actually spent in front of the LSTs in another room. His listening room was tiny compared to the room the LSTs were in. You couldn't really hear his stereo in the "listening room" and I spent very little time in there.

Your query motivated me and I now have a lead on someone who might be willing to try to carefully bring those old KLH's up to power.

And thanks for the note of sympathy, Vern. I get exasperated with people who let the un-preventable misfortune of others send them into a deep blue funk as though it happened to them. I'm gettin' over it. I just shouldn't have waited so long to call, you know?

Bret

[dynaco_dan]

Hi Bret

I just happen to see that you had added another message.

Sorry I missed it until now.

I'm happy you are feeling better as well.

I'm up for a few minutes and went to my records from my database regarding The Audio Amateur and the KLH Nines.

Please keep a printout of this list as I will try to get around to the actual issue for the factual information.

The Audio Amateur

1970 issue 4 page 20 Janzsen Speaker

Speaker Builder re KLH Nine

year & issue 1991 issue 2 page 85 & 86

1991 3 89, 90, 91, 92, and 93

1995 2 24

1995 8 56

I do have the original magazines and when I'm feeling better I'll look up and let you know what is pertinent.

When I was bored years ago I compiled a database ( now 1700 records ) of Dynaco mods, AR mods, Crown mods, Leach, KLH and service tips. etc.. hoping that this would be a lot quicker finding something I was looking for rather than thumbing through the 5 or 6 boxes that I have.

This lookup took me less than 5 minutes.

I do remember something about a series of diodes being added or replaced.

Have a great day, Bret.

Vern

>>He had great taste and probably an empty fridge also.<

>

>Oh, he was world's best bargain-hunter. He bought the LSTs

>from a "fire sale store" (liquidated failed stores' inventory)

>for less than the price of a pair of 3a's. I was there and he

>just made the store an offer well below what the price tag

>said - and they took it. We had to go back and pick them up in

>another car because there wasn't room in the '71 VW fastback

>we were in (the one with two trunks). That was about 1974.

>There wasn't even any way to hear them, so it was a gamble

>that worked-out well.

>

>The KLH-9s didn't show-up at his place until the mid 80s, and

>they didn't work when he got them, so you can bet he found

>them at an estate sale or something. He was good at that.

>He'd buy non-working expensive stuff for $15.00 and spend a

>couple of hours and $.50 fixing it. He had stacks and stacks

>of used electronics. Some of it just for the heck of it. I

>was recently reminded of his having a huge CRT cabinet that

>was video "RAM" from whatever year that was popular in

>mainframes - and he had it working, or at least displaying

>something (I think I remember it was just a string of

>characters).

>

>His "listening room" had AR-9LS's in it, but most of his time

>was actually spent in front of the LSTs in another room. His

>listening room was tiny compared to the room the LSTs were in.

> You couldn't really hear his stereo in the "listening room"

>and I spent very little time in there.

>

>Your query motivated me and I now have a lead on someone who

>might be willing to try to carefully bring those old KLH's up

>to power.

>

>And thanks for the note of sympathy, Vern. I get exasperated

>with people who let the un-preventable misfortune of others

>send them into a deep blue funk as though it happened to them.

> I'm gettin' over it. I just shouldn't have waited so long to

>call, you know?

>

>Bret

[dynaco_dan]

Hi Bret

You may wish to go to The Stereophile web-site - archives - speakers, which has about 13 pages of historical reviews.

On about page 12 or 13 is the Infinity Servo Statik 1 review

I would suggest reading, if not printing the entire Infinity Servo-Statik 1 review as KLH Nines were at that time, the two best speakers available.

I'll be back with more data later.

[Guest Bret]

>I do remember something about a series of diodes being added or replaced.<

I wait patiently. Actually, this week is pretty full, but the following week would be a great time for me to go get the 9s and take them to the guy I found. But you never know about my weeks.

Bret

[Guest Bret]

>I would suggest reading, if not printing the entire Infinity Servo-Statik 1 review as KLH Nines were at that time, the two best speakers available.<

I haven't printed it, but I did go and read it. Who would have thought that an Infinity review would have been as much about the KLHs as the Infinitys?

I thoroughly enjoyed reading the article. Thank you for pointing it out to me.

Bret

[dynaco_dan]

Hi Bret

I was cut off before my rattle was saved a few minutes ago.

Just to be sure and keep you up to date, I just sent you an email, regarding The Audio Amatuer issue of 1970.

That article was specific for Janszen 130 speakers and it included a schematic as well. I feel it may be applicable to the KLH Nines so keep both bits of information. The specific problems in 1970 was in the power supply with the high voltage ( over 1000 volts ).

Due to copyright laws I can't place a copy of this article on this website.

I have to dig a little deeper to find my Speaker Builder issues, which are KLH Nines specific, but, will probably be helful to Janszen owners as well.

Have great day, Bret

Vern

ps I wish I could help Mark with his article scanning, as I can function on my bottom better than I can type.

>>I do remember something about a series of diodes being added

>or replaced.<

>

>I wait patiently. Actually, this week is pretty full, but the

>following week would be a great time for me to go get the 9s

>and take them to the guy I found. But you never know about

>my weeks.

>

>Bret

[Guest Bret]

>An acceptable solid state amp was the Crown DC300A.<

I have just made an offer (too low, it's true) on a working Crown DC300A. I just hope that I offered enough for the guy to have pity on me!

It is a goal to get these set-up for her to enjoy before my aunt dies or moves away. Thank you for the suggestion. I'll let you know if I get an amplifier.

Bret

[dynaco_dan]

Hi again Bret

That would be a very good choice of amplifiers for the KLH Nines.

I think once running, your aunt will be able to remember some of the enjoyment she and your uncle had with them.

I am sure some others, might suggest a newer amp.

If you can buy a used one in nice cosmetic condition, and working for $300 +/- US, you will have, in my opinion, very good value.

A decent matching pre-amp is the Crown IC-150 ( my first choice ), IC-150-A, Dynaco Pat-4, Pat-5, or Pat-5-Bi-Fet or ( maybe even Pas-3x, expensive because of collectability ).

These also are used and can be obtained from about $40. up to maybe $200. US, except the Pas-3x.

I haven't located " The Speaker Builder " box of books yet, but I hope thus far, that the info I did send you, was of help.

Maybe your aunt will invite us all for a listening session, once it's up and running? lol

When you made your offer, did you have a onion in your handkerchief? lol

Have a great night, Bret.

Vern

>>An acceptable solid state amp was the Crown DC300A.<

>

>I have just made an offer (too low, it's true) on a working

>Crown DC300A. I just hope that I offered enough for the guy

>to have pity on me!

>

>It is a goal to get these set-up for her to enjoy before my

>aunt dies or moves away. Thank you for the suggestion. I'll

>let you know if I get an amplifier.

>

>Bret

[Guest Bret]

>When you made your offer, did you have a onion in your handkerchief? lol<

Must have been crying just right. The kind soul took the offer (which really was too low, even in my own book).

It's on its way, but then I had this weird revelation: I could have purchased a new Crown "professional" amp for the same money. Evidently the new ones don't mind 2ohms. If I understand, the DC300A doesn't mind a dead short, though, so maybe that's the wiser choice.

I think there ought to be an old Dynaco amp in the garage somewhere, but the only amps I think I might find are Carver.

Bret

[Guest Bret]

Vern -

You are going to love this.

There are two pair of KLH-9s in her garage. Two. I only knew of one pair. . . which makes me wonder what my uncle was up-to.

And she thinks the AR-LSTs may be in a box somewhere. . . she says she thought she gave them to M.I.T. when she left MA, but she thinks she recalls seeing them in Phoenix when she lived there a short while.

Holy mackeral.

Bret