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Type AA's...


svberger

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21 hours ago, svberger said:

My journey continues. Have a pair of '77 La Scala's that came with the original metal can caps on the AA's. Liked the sound as is and resisted refreshing them. Then I gave in, bought some new Type A crossovers with Sonicaps from the company  who shall not be named(went with A's because I disconnected the zener diodes and so figured no reason to get the AA's). Had them in for several months, no issues, liked them just fine. Not much difference after they seemingly broke in some. I also decided in that time that when @deangwas up and running I would order some new, Klipsch approved crossovers from him.

 

Last night I was bored, so threw in the old crossovers again, and man if they don't sound really good. I figured they would be a little duller then the new one's, but they're not. All the detail and high end is still intact, but there is a nice warmer overall presentation that seemingly was missing with the newer X/O's. Probably just in my mind, and probably my 65 year old ears doing their thing. But I like what I'm hearing, and think I'll leave these in there. At least until I'm able to get the approved variety's in there. 

 

Over and out.

 

 

 

Not all of the old xovers I've had needed to be recapped.  I'm sure the AAs do sound better than the As.  The tweeter section adds needed EQ and attenuation to the K-77.  In a home setting, the -M tweeter should not need the zener diodes.  If you still have original K-77 tweeters, I'd reconnect them until you can install the -Ms ribbon lead diaphragms.  The K-77 is rated at 2 watts continuous/20 watts peak.  The -M is rated at 5 continuous/50 peak.  Change the diaphragm and you'll get the higher rating. 

 

Better yet, Try to find a pair of K-77-Fs(?) that flush mount the tweeter mouth to the front of the cabinet.  or send me a PM. 

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11 minutes ago, JohnA said:

 

Not all of the old xovers I've had needed to be recapped.  I'm sure the AAs do sound better than the As.  The tweeter section adds needed EQ and attenuation to the K-77.  In a home setting, the -M tweeter should not need the zener diodes.  If you still have original K-77 tweeters, I'd reconnect them until you can install the -Ms ribbon lead diaphragms.  The K-77 is rated at 2 watts continuous/20 watts peak.  The -M is rated at 5 continuous/50 peak.  Change the diaphragm and you'll get the higher rating. 

 

Better yet, Try to find a pair of K-77-Fs(?) that flush mount the tweeter mouth to the front of the cabinet.  or send me a PM. 

I have K-77's on mine. They sound good to me.

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4 hours ago, KT88 said:

 

I am completely with you on this point, svberger. There is only one objection. As soon as you see the slightest liquid it is dangerous for your health. The old caps contain PCBs which was used for cooling. @deang will know if the old Aerovox caps Klipsch used are affected. PCB is extremely highly toxic and it spreads in the air when you see droplets of it.

 

Not true.  PCB is used in high voltage xfmrs and the like to retard fire and heat breakdown; it is nearly inert and almost will not breakdown.  It is difficult to get it to burn in a coal-fired furnace at 3000F.  It was not used in the motor caps Klipsch put in the Type AA.  I doubt the older boxy caps used in the Type A had it either.  It's pretty expensive stuff. 

https://www.tedss.com/2020005873

 

But a leak means replacement is needed.  The oil conducts heat and improves the insulation of the dielectric.

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5 minutes ago, JohnA said:

 

Not true.  PCB is used in high voltage xfmrs and the like to retard fire and heat breakdown; it is nearly inert and almost will not breakdown.  It is difficult to get it to burn in a coal-fired furnace at 3000F.  It was not used in the motor caps Klipsch put in the Type AA.  I doubt the older boxy caps used in the Type A had it either.  It's pretty expensive stuff. 

 

But a leak means replacement is needed.  The oil conducts heat and improves the insulation of the dielectric.

 

Honestly, I'm not the type of guy who has to be right. On the contrary, I am very glad that you have clarified it. But on the other hand, do you know if the oil in the old Klipsch capacitors is completely harmless?

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6 minutes ago, KT88 said:

 

Honestly, I'm not the type of guy who has to be right. On the contrary, I am very glad that you have clarified it. But on the other hand, do you know if the oil in the old Klipsch capacitors is completely harmless?

Didn’t hurt me none…

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6 minutes ago, KT88 said:

 

Honestly, I'm not the type of guy who has to be right. On the contrary, I am very glad that you have clarified it. But on the other hand, do you know if the oil in the old Klipsch capacitors is completely harmless?

 

No.  But it should be no worse than motor oil.  You wouldn't lick that off your fingers. 

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It would be really cool to compare caps, just wish I had more patience and time to let things breakin rather that just listening but with winter coming may just do. My 78' Cornwall have Sonicaps and sound ok, perhaps a little too bright sometimes ?  I have a set of original oil (non leaking) caps here, and have been curious about the JEM caps.

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Just for info those old can caps are motor run caps designed to work in your home air conditioner among other uses. The oil is there to keep the cap cool for it's designated purpose. Never intended for crossover networks but is great for that use as well. Not like the old paper in oil capacitors where the oil is there to prevent the paper from absorbing moisture from the air shorting the cap. The oil is not needed for any purpose in a crossover network and I dare to say pour the oil out and the capacitor should work perfectly fine in a crossover network environment. Not that I would do so but just so one understands what the oil is there for. They are prone to leak laying down. Especially the ones made decades ago. If it leaks sitting it upright on the crossover board will solve the leaking problem and it will function just fine. All the talk of the ESR of a cap is over rated when it comes to crossover capacitors. A few micro numbers over spec does not mean it is bad, just getting weaker. Could actually improve the sound for many listeners. For a cap to be bad the ESR number would have to be much more than spec and not just a few fractions out of spec. Rarely happens in a crossover network. In other words when you buy a new Heritage speaker you really have no need to replace anything in your lifetime. Made that way from the beginning and from all I have seen on net the same today. As far as oil in cap being dangerous, I seriously doubt it. No need for expensive oil to keep a capacitor from overheating. Most likely just some kind of thin petroleum oil. AC transformers another story, stay away from that oil. When those can caps were used capacitors were expensive. More so than iron. Not the case anymore. 

 

If I were contemplating replacing capacitors in my networks I would definitely go with Klipsch authorized capacitors. Why would one want anything else in their Klipsch speakers? 

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1 hour ago, SonofJames said:

It would be really cool to compare caps, just wish I had more patience and time to let things breakin rather that just listening but with winter coming may just do. My 78' Cornwall have Sonicaps and sound ok, perhaps a little too bright sometimes ?  I have a set of original oil (non leaking) caps here, and have been curious about the JEM caps.

I liked the difference Sonicaps(white one’s) brought to my ‘77 Cornwalls. That era  CW sound has always been a little to thick and muddy for my taste and the new caps seemingly cleared that up some which is an improvement to my ears. The LS’s were never muddy and new caps didn’t hurt the sound but the old caps seem to bring just a tiny more warmth back which makes everything a little more charming for me.

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On 10/6/2022 at 12:02 PM, rmlowz said:

I ordered some from JEM they are only a little over 100.00 with shipping. I am going to see if I can hear a difference with these 65 old ears.

 

Again I ask...how does one know if a capacitor is out of spec when we don't know the factory specs to begin with?

 

It would be interesting if you could measure the capacitance of the old caps vs new ones.  It would very interesting if you could measure the ESR of the old vs new caps, at various frequencies.

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1 hour ago, mboxler said:

 

Again I ask...how does one know if a capacitor is out of spec when we don't know the factory specs to begin with?

 

It would be interesting if you could measure the capacitance of the old caps vs new ones.  It would very interesting if you could measure the ESR of the old vs new caps, at various frequencies.

I don't have any equipment to test what you are asking. My ears are the best testing equipment that I have available. IMHO I think 40-year-old caps are out of spec and need replacing.

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For me the only importance when it comes to speakers caps spec is if there is any danger to the speaker running out of spec caps. With a decades old amp, I definitely want the important caps changed out and updated for mostly safety reasons. But for a speaker, if a cap is out of spec, but being that way is of no particular risk to the speaker, listening to the speaker and deciding if I like the way it sounds is of most importance. I have no doubt that 40 year old caps in most cases are out of spec, but like component break in, or patina on a leather jacket, that might add to the overall presentation in ways that new caps will not. Again, this is highly personal and I have no issues with folks who disagree. But I've listened to enough gear and music, both recorded and live, over the course of 50+ years of doing it that I have a pretty good handle of what I like and what is right for me. That won't necessarily stop me from experimenting, as I did with my recent purchase of C*****S crossovers for my LS's and CW's. And it won't stop me from purchasing the approved Klipsch crossovers from Dean when I'm able to . I'm not stuck in my ways(at least I'd like to think I'm not) but I do know what I like.

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On 10/6/2022 at 5:59 PM, JohnA said:

 

Not all of the old xovers I've had needed to be recapped.  I'm sure the AAs do sound better than the As.  The tweeter section adds needed EQ and attenuation to the K-77.  In a home setting, the -M tweeter should not need the zener diodes.  If you still have original K-77 tweeters, I'd reconnect them until you can install the -Ms ribbon lead diaphragms.  The K-77 is rated at 2 watts continuous/20 watts peak.  The -M is rated at 5 continuous/50 peak.  Change the diaphragm and you'll get the higher rating. 

 

Better yet, Try to find a pair of K-77-Fs(?) that flush mount the tweeter mouth to the front of the cabinet.  or send me a PM. 

 

I wonder what the odds are of finding some K-77-M's that haven't had their diaphragms changed out.  

 

I can't tell, but it sounds like you are suggesting the K-77-F has the 5 watt rating, but it doesn't. Also, the K-77-F will only fit if the cutout is large enough. So, that would be anything where the Z-brackets were supported.

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6 hours ago, mboxler said:

 

Again I ask...how does one know if a capacitor is out of spec when we don't know the factory specs to begin with?

 

It would be interesting if you could measure the capacitance of the old caps vs new ones.  It would very interesting if you could measure the ESR of the old vs new caps, at various frequencies.

 

Not just various frequencies, but voltages too.

 

The dielectric material will dominate these measurements, and all you really have to do is measure a new to know what the old ones should be.

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20 minutes ago, deang said:

 

I wonder what the odds are of finding some K-77-M's that haven't had their diaphragms changed out.  

 

I can't tell, but it sounds like you are suggesting the K-77-F has the 5 watt rating, but it doesn't. Also, the K-77-F will only fit if the cutout is large enough. So, that would be anything where the Z-brackets were supported.

 

K-77-Ms don't need the diaphragms replaced.  They came with the ribbon lead diaphragm that carries the higher rating. 

 

Perhaps they were not -Fs, but the K-77-? I saw in the Lab would have fit my '81 LS.  The flange perhaps pushed the mounting screws wider, but wasn't definite. 

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5 minutes ago, JohnA said:

 

K-77-Ms don't need the diaphragms replaced.  They came with the ribbon lead diaphragm that carries the higher rating. 

 

Perhaps they were not -Fs, but the K-77-? I saw in the Lab would have fit my '81 LS.  The flange perhaps pushed the mounting screws wider, but wasn't definite. 

 

Right, if you can find some unmolested K-77-M's, they would have the higher rating, but you wouldn't know what you actually had until you opened it up.

 

Not always easy to keep the tweeter thing straight. Since John Allen owns the tooling for these things, I will call him later for clarification.

 

4/2006: The horn portion of the K-77-F tweeter was re-tooled to include a recessed
flange eliminating the need for the separate "Z" bracket and attachment rivets.
This also allowed the updating of pre-Z bracket Klipschorns (prior to Feb
1,1983) to flush tweeter status without motor board modification. This variant
was designated as the K-77-D.

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5 hours ago, rmlowz said:

 

I don't have any equipment to test what you are asking. My ears are the best testing equipment that I have available. IMHO I think 40-year-old caps are out of spec and need replacing.

 

I don't trust my ears until I see some measurements first. Some things I hear simply don't show up, because most people I know aren't sitting on a full blown lab. You need some kind of baseline. Ears alone are notorious liars.

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I wonder if mounting the K77 flush to the front of the baffle is the crux of the matter. Having been busy with other speakers lately, I'm returning to my Lascalas. I still have very original K77 M as a replacement tweeter. My 1977 are original K77 Alnico with re-strengthened magnets. I like the old Alnicos better in the horizontal arrangement in the LaScala. The K77M hiss more. But I will build a small baffle very soon with the thickness given by EV which is a bit thinner than the LaScala baffle. Then I will mount the K77 M vertically and put them on the LaScala and then I will compare the sound. Just as the K77 and K77M were intended. I will see if the sibilance is gone. In my opinion, it is counterproductive to cure a tweeter that a) should be mounted vertically and b) needs a baffle on which it should be mounted from behind by keeping it horizontal and taking the baffle away completely. I would not be surprised if there will be a good result. Because the T35 is a diffraction horn that only emits far horizontally when it is mounted vertically...with a baffle in front of the horn so that the waves spread horizontally.

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On 10/6/2022 at 2:59 PM, JohnA said:

 

 The K-77 is rated at 2 watts continuous/20 watts peak.  The -M is rated at 5 continuous/50 peak.  Change the diaphragm and you'll get the higher rating. 

 

 

This is screaming to anyone using these to add a fuse or auto bulb, especially as hard as it is to get good replacements nowadays (unless that has been solved).

 

 

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