Beginning the RCA LC-1A adventure.

Question: is it an audio sin to recone an LC-1A with a non-hump cone?

SpeakerExchange tells me that they can work on the speakers, but the cone will be an aftermarket replacement.

If I'm not able to get original parts, I think the better option is to have a functioning pair of speakers than not...
 

gable

Senior Member
I would probably wait awhile, see if other options turn up. It's possible there are not any other options, but I tend to think that it's worth being patient to try and search them out.

You might reach out to Dave from Planet10, he used to do a lot of vintage refurbishing and may have some resources.

planet_10 hifi
 
@Salectric, heard back from Millersound - they do not have parts and thus do not feel confident they could maintain their high standards while working on these speakers. That denial is a true sign of quality work in my book. They did, however, recommend I reach out to Jonathan Weiss of OMA, which I did.

Jonathan has been of great service to me in the past year as I've tracked down old RCA gear. He had helped me work through the different parts of an old Photophone theater system I picked up last August.

I placed a call to the number listed on OMA's website and was surprised when Jonathan picked up. He was kind enough to talk about RCA and not his own business - in his words, with a broken LC-1A it's best to just walk away. Repair parts for a blown tweeter don't exist; he asked for an update if I did find anything out about possible repairs, otherwise he said it's best left as a parts unit.

I've got these boxed up for the time being while I continue the search for repairs. Art Dudley's writeup on the speaker made it seem like parts could exist somewhere - I wonder if it's possible to reach out to him.
 

Salectric

Senior Member
@Salectric, heard back from Millersound - they do not have parts and thus do not feel confident they could maintain their high standards while working on these speakers. That denial is a true sign of quality work in my book. They did, however, recommend I reach out to Jonathan Weiss of OMA, which I did.

Jonathan has been of great service to me in the past year as I've tracked down old RCA gear. He had helped me work through the different parts of an old Photophone theater system I picked up last August.

I placed a call to the number listed on OMA's website and was surprised when Jonathan picked up. He was kind enough to talk about RCA and not his own business - in his words, with a broken LC-1A it's best to just walk away. Repair parts for a blown tweeter don't exist; he asked for an update if I did find anything out about possible repairs, otherwise he said it's best left as a parts unit.

I've got these boxed up for the time being while I continue the search for repairs. Art Dudley's writeup on the speaker made it seem like parts could exist somewhere - I wonder if it's possible to reach out to him.
Bummer. I imagine that will be a problem with a lot of very old collectible gear, and the situation can only get worse as time goes by.
 
Ok, well that was painful. Had to register to comment of course. Had to switch machines to retrieve the confirmation. Then search to find this thread again. Search doesn't like RCA or LC-1A, to short a phrase to search. Eventually I used MI-114111.

I usually find these threads when they're long dead.

There are a few people that know a surprisingly large amount about these speakers. I'm still collecting information.

I inherited my 3 speakers from my brother, who acquired them back in the 70's. We were amazed at quality of voice reproduction. Problem was they didn't sound anything like the JBL studio monitors of the time, so mixing on them was a disaster. That's how I got them.

From what I've found out so far, they have become notorious for aging poorly. The tweeters were super fragile. Matching from drive to drive was very poor. All that said I still love mine, and I've converted my wife into a believer.

The front or outer surround was reportedly doped at factory, and this doping changed over time causing the surround to stiffen. The three I have were all "treated" for this affliction. Unfortunately the individual used Kodak Photoflow to soften the surround. Over time this will leave the appearance of water damage. The solution continues to migrate through the paper drawing in moisture from the air. With my speakers the surrounds eventually turned to mush. I used various hacks to strength the surround. After I spent days gently flushing the treated areas with water to remove the Photoflow, once I understood what was happening to my speakers and why.

The bumps as you've all noticed are a "push here" target for inquiring fingers and cat paws. My solution/fix is to use some water to soften the bump to be repaired and a low power vacuum clearer with wand attachment to pull the bump out. Mostly works. Cosmetic results will vary.

The tweeters on the original LC-1 (no bumps) and LC-1A, were reported as being rated at some ridiculous power of 5 watts. The replacement tweeter and the version in LC-1B and LC-1C were said to be rated at 40 watts.

One of my three had a blown tweeter. The enamel was completely burnt. I'm told that there is 17 feet of aluminum wire on the voice coil. Don't know about this. Parts were scarce even back in the 70's. There was supposedly someone in Camden that had bought all the spairs. Not knowing how to contact that person, I got brave and wound my own voice coil using the finest wire I had at the time, #44. My first attempt was a fail. Voice coil was to tight. Second attempt actually worked. For those interested, just really thin paper and metal lacquer holding it all together. That speaker is in my basement for music while working on other projects. The other two are currently stored in vacuum pages with silica-gel packs. I recently did a sweep test on that speaker, its has output to 15k Hz. Then its gone, which is ok as I can't hear that high anymore. With all the peaks and dips from room reflections you really can't tell if there is a level mismatch. I can't hear one anyway. The other speaker that sits with it is a JBL 4312 with titanium tweeter, just no comparison to the RCA.

Hope this story will inspire you all. Even in their near dead condition these are still great speakers worth the effort.

Oh and if you hear of a source of parts let everyone know.
 
Ok, well that was painful. Had to register to comment of course. Had to switch machines to retrieve the confirmation. Then search to find this thread again. Search doesn't like RCA or LC-1A, to short a phrase to search. Eventually I used MI-114111.

I usually find these threads when they're long dead.

There are a few people that know a surprisingly large amount about these speakers. I'm still collecting information.

I inherited my 3 speakers from my brother, who acquired them back in the 70's. We were amazed at quality of voice reproduction. Problem was they didn't sound anything like the JBL studio monitors of the time, so mixing on them was a disaster. That's how I got them.

From what I've found out so far, they have become notorious for aging poorly. The tweeters were super fragile. Matching from drive to drive was very poor. All that said I still love mine, and I've converted my wife into a believer.

The front or outer surround was reportedly doped at factory, and this doping changed over time causing the surround to stiffen. The three I have were all "treated" for this affliction. Unfortunately the individual used Kodak Photoflow to soften the surround. Over time this will leave the appearance of water damage. The solution continues to migrate through the paper drawing in moisture from the air. With my speakers the surrounds eventually turned to mush. I used various hacks to strength the surround. After I spent days gently flushing the treated areas with water to remove the Photoflow, once I understood what was happening to my speakers and why.

The bumps as you've all noticed are a "push here" target for inquiring fingers and cat paws. My solution/fix is to use some water to soften the bump to be repaired and a low power vacuum clearer with wand attachment to pull the bump out. Mostly works. Cosmetic results will vary.

The tweeters on the original LC-1 (no bumps) and LC-1A, were reported as being rated at some ridiculous power of 5 watts. The replacement tweeter and the version in LC-1B and LC-1C were said to be rated at 40 watts.

One of my three had a blown tweeter. The enamel was completely burnt. I'm told that there is 17 feet of aluminum wire on the voice coil. Don't know about this. Parts were scarce even back in the 70's. There was supposedly someone in Camden that had bought all the spairs. Not knowing how to contact that person, I got brave and wound my own voice coil using the finest wire I had at the time, #44. My first attempt was a fail. Voice coil was to tight. Second attempt actually worked. For those interested, just really thin paper and metal lacquer holding it all together. That speaker is in my basement for music while working on other projects. The other two are currently stored in vacuum pages with silica-gel packs. I recently did a sweep test on that speaker, its has output to 15k Hz. Then its gone, which is ok as I can't hear that high anymore. With all the peaks and dips from room reflections you really can't tell if there is a level mismatch. I can't hear one anyway. The other speaker that sits with it is a JBL 4312 with titanium tweeter, just no comparison to the RCA.

Hope this story will inspire you all. Even in their near dead condition these are still great speakers worth the effort.

Oh and if you hear of a source of parts let everyone know.
Glad this alive is well enough to get some fresh blood. And thanks for going through the effort to sign up - welcome, this is really a fantastic bunch.

I've gotten word that there is someone who has experience repairing these. Don't know how yet - I haven't asked yet as I'm afraid to spend too much money repairing these at the moment, knowing full well that that's exactly what I want to do. I'll provide an update when there's real information to be shared.

These speakers are going to stay with me for a while. Working or not, they're too cool to purge. I'm very much looking forward to hearing perfect pair, but even a partially revived pair will do me well given the inklings I've heard out of my one working speaker.
 
Glad to read that you're still active on this project. You asked way back when about reconing. Yes it would be an audio-sin to recone with an after market cone. Not for the collect-ability value, but more from an engineering point of view. The cone is very specific on the LC-1 series speakers. Shallow, very stiff, and very heavy compared to the typical high efficiency speaker. You'd have a very different creature in the end.

I did see an ad about a year ago for a recone kit for an actual LC-1A, RCA replacement part. Beinging sold out of Japan. The parts do surface once in awhile. I've never seen the bumps show up. When I look long enough at them they look a lot like the cones of those tiny oval speakers that where around years ago.

I've considered redoing the surrounds on mine. Using a fabric version as was used on the LC-1C. They're still working properly, no rubbing, so I'm leaving well enough alone.

I'm curious about the LC-1's tweeter arrangement. Can you post a close-up of the tweeter. Later models had a "butterfly" deflector mouned in the centre of the tweater. I'm curious of what they did on the first model.
 
Question: is it an audio sin to recone an LC-1A with a non-hump cone?
If by that you mean an original RCA "non-hump" cone as found in the early MI-11411 speaker, no, not a sin. The "bumps" don't make that much of an audible difference. I might not use one in a stereo pair with another cone having the bumps, but if it's all that's available.....

But if by the above you mean using some sort of generic or other brand replacement cone in an LC-1A, yes, that's a sin. You won't end up with anything like the original LC-1A sound unless you use original RCA cones. Sorry. True dat.

Over the years, I've had dozens of these speakers of all versions. The RCA cones are very unique. Never seen a replacement that was even close.

Oh and if you hear of a source of parts let everyone know.
Hate to be the one to say this, but you won't. What few NOS RCA parts there may ever have been are long since used up or in hoards by now. If you're lucky, you might get a shot at a hoarder's estate, or some obsessive LC-1A owner with money and ambition may try and reproduce them, but even that's a long shot, given the extreme expense in so doing and the limited opportunity for any kind of return on investment.

They're still working properly, no rubbing, so I'm leaving well enough alone.
Very wise.

Later models had a "butterfly" deflector mouned in the centre of the tweater. I'm curious of what they did on the first model.
Early tweeter (in the MI-11411--no "humps" or butterly) is the same as the LC-1A tweeter. It just has the center screw, but no butterfly. I don't have a photo, but maybe someone can post one.
 
Went back to the OP's starting post. Now that I have an Account the pictures are visible.

Do you think they're related?
IMG_5488.JPG

Regarding the bumps, I can't hear a difference when I'm in front of it. My understanding was they're greatest effect was off-axis. Now there I can tell the difference. I walk all around the room with little change. With my single JBL, get five or six feet off-axis and you're listening to a completely different speaker. Someone once said that the RCAs were flatter off-axis. Some day I may measure them to see if that's true.
 
Greetings fellow hi-fi-ers! While doing a search for the production dates for the RCA LC-1B drivers, I came across this thread on this forum and just had to join.

I'm the guy that Nate (aka Redboy) mentioned having had some RCA reproduction speaker enclosures made for my LC-1s. The cabinets that I had made were copies of the RCA LS-11 cabinets and the drivers I'm currently using are two LC-1Bs, one an original and one an MI-11411 that was returned to RCA for an upgrade, back when they did that. I know that because I have a friend who lucked into some that came out of Radio City Music hall that were also upgraded MI-11411 drivers and he was told by Hans Dietz, the RCA engineer who headed that last rendition of this great speaker, the LC-1C, that RCA was known to just upgrade an earlier LC-1 to the latest version when a customer would send one back with issues.

You're correct about Jonathan Weiss being most helpful, he was with me as well when I called him after finding my first pair of LC-1s. Like you, I found an LC-1A in one cabinet and an MI-11411 in the other. He said that it would probably be best to swap either one for a match, if I could and it just so happened that I had a friend with an extra MI-11411 in great condition that he was willing to trade for my LC-1A. Not being able to hear the difference myself, it didn't matter to me which driver I matched so we did the deal.

Jonathan Weiss advised me when I inquired about the value of the speakers I'd found he was forthcoming about what I could get for them with a caviat and that was, in his opinion, it would take 10 times the $3500 I could get for them to replace them with anything as good or better!! Well, that being said, I had a cracked sewer line inside the basement and the crack extended through the basement wall that had to be taken care of and that $3500 would take care of it so I sold them to a friend.

Within two weeks I regretted that move and asked him if he's sell them back to me but he had already fallen in love with the sound and declined. Oh well, I had some other speakers that are pretty highly regarded so I figured I'd just be happy with them. I was wrong. After having the LC-1s in my home for months, those other speakers just weren't cutting it so I went on a search for the elusive LC-1 drivers.

With lots of searching and non-hesitation when something showed up, I got another pair of MI-11411 drivers and then three singles, and then I found a pair of LC-1B drivers, and then a couple single LC-1B drivers. After finding the B's, I met a local cabinetmaker who was willing to attempt to replicate the LS-11 cabinets and when they were finished, I put my LC-1B drivers in them and my system was once again transformed.

One of the LC-1B single drivers I got was in an original LS-11 cabinet which is what my cabinetmaker used as his template and which I still have. I'm toying with using it in a mono setup but I don't own a single 78 record and only a handful of mono LPs so it would only be for FM radio, which to me sounds better than stereo FM, but I haven't decided yet. Anyone close enough or willing to drive here, can borrow my LS-11 cabinet for their cabinetmaker to copy. It's a lot more complicated than it at first appears.

My guy quoted me something like $750 for a pair of them but when he delivered them told me he wouldn't be making any more. I asked him why and told him that I was interested in another pair and I had a couple friends with LC-1s that were interested. Then he rephrased it and said that he wouldn't be doing any more fore the price he charged me. I told him that he should charge me what they cost plus his time and that I didn't have a problem with that. In fact, I told him I thought he misjudged the work involved in them from the start. But, being an honest businessman told me that he was sticking to his quote but from then on, they'd be about 3 times what he charged me. I told him no problem, they're worth that to me.

I was disappointed to hear that your non-functioning tweeter was all burnt looking because I have a friend who has found one or two broken tweeter voice coil wires and been able to reconnect them and bring those tweeters back to life. Two of mine are burnt looking like yours and they're beyond repair so I've got a couple MI-11411 drivers that need tweeter voice coils, waiting in the wings.

Anyway, I've hogged up enough space for my first post here. I'm happy to help any way I can but I don't know much more than I've just relayed here. I was planning on attaching some photos of my repro LS-11 cabinets but couldn't find them in my computer nor could I find the pics that I know I uploaded onto the AK site!! When I find them, I'll post them or, I can send them in a text as I found some on my phone.
 

BillWojo

Junior Member
I was reading this thread with interest because I know a guy that has speakers like these. As a matter of fact I was lucky enough to hear them in his living room. I thought, gee I should contact Nelson and tell him about this thread and what do you know! He has the last post.
I bet there are a few of these speakers somewhere around the Southern NJ or Philly area due to RCA being in Camden. Maybe even parts but how to contact the owners or descendants is a big mystery. I remember one estate sale where LC-1's were listed a while back. I'm sure they were not cheap.

BillWojo
 
Glad to hear from another dedicated owner. Love the back stories. I remember decades ago that if you said you had one of these speakers people would look at you as if you were speaking Martian. I wonder sometimes how many of these have gone into dumpsters because someone looked at them, saw the pushed in bumps, and said they were trash. Had no idea how special it was.

nelsress, if you're ever feeling brave sometime, I'd be interested in some measurements from your burnt tweeters. Wire thickness? Length of wire? Is it Aluminum wire? For years I'd saved some burnt magnet wire, couldn't remember why I was saving it. Now I can't find it, think I tossed it, and it was probably the wire off one of the voice coils.

The paper cone and Bakelite carrier are fine on the ones I have. It should be possible to find someone that can wind a replacement voice coil. Better than the version I made. I remember being told the the replacements handled more power, but weren't made as well. I can believe this as I have two replacements, both are almost impossible to align, the voice coil is mounted at an off angle. I can remember shaving the end off one and sanding the inside of the former to get enough clearance.
 
@David R I've decided that it's worth writing whatever we do on things like this so that there are words to go to whenever someone finds them and wonders if the trash is the place for them.

I haven't played with these speakers much this year, but I plan on digging them out and building open baffle JElabs has published (JE Labs Open Baffle redux). Last month I saved a very vintage tube amplifier from the trash that had absolutely no business being trashed. I'm hoping to have it back in my possession in the next month and will provide a better update on both these speakers and that amp then. Right in time for cold-ish weather. (We Texans can't pretend to understand cold.)
 
@David R I've decided that it's worth writing whatever we do on things like this so that there are words to go to whenever someone finds them and wonders if the trash is the place for them.

I haven't played with these speakers much this year, but I plan on digging them out and building open baffle JElabs has published (JE Labs Open Baffle redux). Last month I saved a very vintage tube amplifier from the trash that had absolutely no business being trashed. I'm hoping to have it back in my possession in the next month and will provide a better update on both these speakers and that amp then. Right in time for cold-ish weather. (We Texans can't pretend to understand cold.)
The dreaded JE lab...do the OB,you won’t regret it. Plan on subs to fill in the bottom.
Mine are Altec 605b OB with cheap no name subs.
Next try will be Altec 414z OB/32c/902 with some good subs...one day.
 

Audionut

Next Round Is On Me
@David R I've decided that it's worth writing whatever we do on things like this so that there are words to go to whenever someone finds them and wonders if the trash is the place for them.

I haven't played with these speakers much this year, but I plan on digging them out and building open baffle JElabs has published (JE Labs Open Baffle redux). Last month I saved a very vintage tube amplifier from the trash that had absolutely no business being trashed. I'm hoping to have it back in my possession in the next month and will provide a better update on both these speakers and that amp then. Right in time for cold-ish weather. (We Texans can't pretend to understand cold.)
Could you give a hint or tell which tube amp this might be?
I am cheering on for you in making the speakers whole and sing again like their glory days.
 
Could you give a hint or tell which tube amp this might be?
I am cheering on for you in making the speakers whole and sing again like their glory days.
I appreciate the cheers - I'll appreciate the speakers even more.

I shouldn't be coy about the amp - I found a Western Electric 124. Don't ask me how, or what kind of karma I have left to my person, one came to me. I was discussing a project with a very respected builder before the find and they asked if they could repair the amp for me. I obliged. I know the transformers are good, so I'm just gearing up for a little trip to go retrieve it.

So, beers at my place when I hook up an LC-1A to a WE 124.
 
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