My Kappa 9 restoration

[seifreit]

Part 1 - The beginning

As the title states, this is a documentation of my Kappa 9 restoration journey. A little background first. I acquired them from the original owner just over two years ago. They were the first vintage Infinitys I had purchased, in fact at that time, Infinity wasn't really on my radar. The owner was also selling some Onkyo Integra gear that I was interested in and as I was leaving she showed me the Kappa 9s and asked if I was interested in them too. They were pretty rough, all four woofer foams gone and not much left of the poly dome material, rough looking grills, etc.

I asked her if I could have a day or two to think about it and went home to do some research. I realized they were somewhat special speakers and had some value in good working order. I did some math and figured I could flip them and make a few bucks if I could get them cheap. I called her back and offered her $125 for them. She was happy to take the $125 so I picked them up and took them home. As I did more research I decided that maybe I shouldn't flip them. I decided to get them up and running, doing what would be minimal to make them functional and get them into the house for a listen.

 

[seifreit]

Part 2 - Getting them up and running

So, I got a set of 4 woofer surrounds from my local speaker repair shop. Before attempting to re-foam them I decide it would be best to try re-foaming something less valuable first. I bought a pair of Reference Fours cheap that need woofers and mids re-foamed and figure this would be good practice as they also have IMG woofers. I also researched the best option for getting the polydomes repaired/replaced. Popular consensus at that time seemed to be sending them off to MillerSound and have Bill do his magic. I contacted them about price and time line and soon they were on their way to him.

While waiting for the polydomes to get back, I re-foamed the woofers and addressed a couple minor cabinet issues. Once the polydomes arrived, they got installed and per Bill's advice, I removed approximately half the poly fill in the polydome chamber and fluffed up the rest. I then hooked them up to one of the amps in the shop and ran them for a few hours at low levels to make sure everything was working ok before the move into the house.

While waiting for parts and polydomes to return, I pondered how and what I would drive them with. I happened to have two Onkyo Integra M-504 dual mono-block amps(one from the original owner of the 9s that was used to drive them). I figured the two of them should be able to handle the 9s. I guessed right. They were easily the best sounding speakers I had ever heard or owned up to that point. Even my son was wow'd by them and he has good ears. At that point I decide that these were never going to be flipped and may never even leave the house again. It didn't take long to make the decision that they should be fully restored, or at least my idea of a restoration.

 

[seifreit]

Part 3 - The restoration begins

With my mind made up that I was going to restore them I knew that I didn't want to be without them or at least something close for the period of time it would take to do what I wanted to do. Taking a page from my earlier experience with re-foaming the Reference Fours first before tackling the 9s I started looking for a pair of Kappa 8s I could perform the same restoration to. The crossovers in the Kappa 8s are nearly identical as the 9s so this would give me a good idea of what to expect with a recap of the 9s. I also wanted to see how much of a "gap" there was between the two siblings. And, I would have a nice set of Kappa 8s when done, win-win. It took a little while to find Kappa 8s close enough and at a price I could live with knowing what I would be spending to "restore them.

I finally found a set a little over an hour away. The woofers had been redone recently and the cabinets where in pretty good shape but as usual, the polydomes had to be done. So, off they went to Bill at MillerSound. In the mean time, I set out trying to decide what I would do for a recap. My goal was to try to put them back to a close to the original sound as a new set as I felt possible. I also had a specific budget in mind and buying a lot of really expensive poly caps was not in the budget. I decided on just replacing the electrolytics. I had read lots on this forum and others about guys who had replaced the original yellow film caps and weren't happy and my restoration goal was not to change or try to improve on the original sound but get as close as i thought they could be. I chose Mundorf AC E-Caps as they are 5% tolerance like the original Culvers and I had read somewhere that Arnie liked them for electrolytics. I'll try to cover some of what I did with the 8s in a different thread devoted to that project. Needless to say, when I finished them and moved them into the main system, i was quite pleased. Next, the main event with pictures to assist those tackling the same process.

 

[swechsler]

I'm waiting with bated breath for pics and instructions on disassembling the Kappa 8 crossovers, as this is work I'll probably be doing in the next year or so.

 

[seifreit]

Part 4 - The real point of all this

With the Kappa 8s in the main system and the Kappa 9s moved out to the shop the real work began. This is what I wanted to accomplish with the end goal being a set of Kappa 9s that I felt would be a close to original in sound and look as possible.

1) Replace all the aging electrolytic caps but leave the yellow poly caps in place
2) Replace all 4 EMIT diaphragms
3) Address any cosmetic issues with the cabinet that were not done before
4) Replace the worn grill cloth

Not a long list but plenty to do. As I was happy with the result from using the Mundorfs in the 8s I went the same route with the 9s. Since I had practiced everything on the 8s, removing the crossover from the 9s was "easy". For those looking to tackle a recap here is a picture of the crossover board.

Red circles indicate what needs to be un-soldered and the yellow circles show where the stand-offs are that will have to be released. Unsoldering the leads that come from the banana jacks is a bit of a pain as the wires are single strand and fairly stiff. They are folded over onto the board and then soldered. you will have to try to pry them up while applying heat, A good vacuum desolder iron and/or wick is a must. You will also need to unsolder the two leads to the coil on the left edge (from picture perspective). Once these six point are unsoldered and free you will need to release the standoffs working from the left edge where you unsoldered the coil. the board will "hinge" allowing you access to both sides without disconnecting anything else. You can also cut the nylon zip tie that holds the bundle of cables going out to the drivers. It is attached to a hold-down on the main panel. Don’t forget to replace it when you’re done.

So, now to replace the caps. The only drawback to using the Mundorfs is the limited option in values. Many had to be stacked to get the values I needed. Here is the board finished from both sides.

This stacking caused one other issue. One of the larger coils(the one that gets unhooked temporarily) has to be relocated as it hits the new caps.

Not a big issue and something that may not be necessary depending on what caps you choose to use. This is also the perfect (and really the only) time to de-ox all the level controls. Next on the list was replacing all the EMIT diaphragms. You may ask why as they were all working. These are 30+ year old speakers and I want them to last another 30+ years and I could see the ripples through slots so while i was there...

Here is a picture that shows the difference between a 30 year old diaphragm and a new one from BobbyD38 (can't say enough about how much his efforts to provide us with spare parts are truly appreciated).

The old diaphragm is on the right and new one on the left. You may also find that one of the terminals has a piece of cheap masking tape around it. This was done to insulate one of the terminals from hitting the frame and possibly shorting out if both terminals rub the frame. If you decide to install new diaphragms in your EMITS you may find they are glued together. They actually applied a layer of glue around the entire perimeter of the magnet structure. This made it very difficult to separate the old diaphragms from the front panel. I was hoping when all was done that I would have 4 good back-up diaphragms. I ended up with 3 because of the glue issue.

Make sure to replace that tape with fresh tape as a minimum. I implement a more permanent solution by using some shrink tube on both terminals.

Now for the cosmetics.

 

[stereofanboy]

I'm waiting with bated breath. . .

I've gotten so used to reading on AK that I was a little disappointed that you didn't spell it baited.

I'm excited to read this thread because I'll have to do this someday.

 

[Bkphoto]

I would get rid of those cheap iron core coils and use laminated steel instead....if you need more room make an additional board...

 

[seifreit]

I would get rid of those cheap iron core coils and use laminated steel instead....if you need more room make an additional board...

I also didn’t cut out the bypassed resister or the original coil that had the leads clipped and another coil installed in its place and glued to the side of the board. These were done at the factory.

My goal was not to really try to improve or alter the original sound as much as it was to get it back to what it would have been new. If I could have found brand new Culver caps exactly like the originals I would have used those. The Mundorf A/C E-caps were the closest I could find.

As a student of history, I wanted this to be as much a “document” of what the speakers were as originally designed while still enjoying them as they would have been new.

 

[Bkphoto]

Some, including Mr Watkins (as he said in an interview that has been on here from time to time) believe 1 part of the super low ohm draw on some big infinity’s comes down to the cheap iron coils....doing so, might in theory help to protect your amp from further damage....

 

[seifreit]

doing so, might in theory help to protect your amp from further damage....

Haven’t run into any amp issues yet, just have to make sure you pick the right amp.

 

[Bkphoto]

Just saying....once you have something all apart it wouldn’t hurt to put something better in, not going to change the sound as much as make it a bit more manageable, a lot of crossover components are due to the bean counters...a 1 ohm load at times is kind of ridiculous

 

[seifreit]

Part 5 - Making them pretty

With all the internal work done it was now time to address the few cosmetic issues that weren't addressed when I first acquired them. I forgot to mention in Part 1 that there was also a base/foot missing so a new one was made and a quick coat of Krylon semi-gloss black applied. Good enough at that time to keep it from tipping over in the house. Now that i had more time, both feet were removed, sanded smooth and a couple coats of the correct Satin Black was applied. Good as new now.

The cabinet had a few minor issues like a couple paint speckles that look as though they had been a result of house painting without covering the K9s with a drop cloth. Again, easy enough to address. There were also a couple of flutes that were coming detached at the bottom so those were glued back in place and then the entire cabinet received a light sanding and an application of Golden Oak stain to match up any of the repairs and nicks that accumulate with age. Danish oil was applied to keep the original satin finish.

Next was the grill cloth. There were a couple small holes here and there and most of the corners were worn through to the plastic underneath. I managed to find grill cloth at my local speaker repair shop that was as close as I could get to the original. It seems finding grill cloth of the same optical transparency is a problem as evidenced by a recent discussion on the Vintage Infinity Collectors FaceBook page. This is how the cloth I got appears

The original cloth is on the left and the new cloth is on the right. The new cloth does not match the same weave pattern as the original but I would be surprised if anyone can find it(if anyone does know where to find original cloth please share).
The original cloth is glued in place and it was rather easy to remove. The hard part was removing the old glue much like it is when cleaning up a cone for re-foaming. The shop were I purchased the cloth from recommend the same glue they use to do re-foams. It worked quite well, no issues with attaching the cloth and having some work time to get rid of any ripples or sags. I was really amazed at how dingy the old cloth looked when comparing it to the new cloth. It made a huge difference in the overall appearance of the speakers.

As i had to remove the badges to do the grill cloth I took the time to clean them up. The badges appear to made of either pot-metal or aluminum. Both oxidize over time and the badges did not have their original brilliance. They were buffed up and one of the small changes I made was to apply a gold-tinted clear coat over the Infinity loop. Kind of a nod to the older gold stick-pin type badges and the later badges that have the loop in gold and letters in silver.


And here they are, not the best pictures as I have a rather old phone, but you get the idea.


In the final post of this journey I will share some observations and thoughts regarding the Kappa 9s and vintage Infintys in general.

 

[Skip Shot]

The background terrain looks like where we used to live... Titusville, FL.

 

[seifreit]

The background terrain looks like where we used to live... Titusville, FL.

Opposite side of the state, due west.

 

[Skip Shot]

Looked familiar.

 

[7.62]

Beautiful Work seifreit, with the new caps how are they sounding.

 

[seifreit]

Beautiful Work seifreit, with the new caps how are they sounding.

Thanks @7.62 . To answer how they sound,

Part 6 - Final impressions and thoughts

I apologize to those of you who have been waiting for this last installment to my RS 9 Kappa journey. Here are a few thoughts I have on the overall sound and some things I've learned.

I wanted to wait for some period of time to allow all the changes, new caps and EMIT diaphragms, to settle in before making any final judgments. As with any speaker "evaluation" these are my impressions, your mileage may vary.

When I first got the 9s I was very impressed by their overall sound. They did appear to be a little bit "bright" so I ran them with the polydome, EMIT and SEMIT controls down a bit. I also had trouble locking in on vocals in particular. They seemed to "wander" across the sound stage. I had read about this phenomenon and some attribute it to a mismatch between the crossovers, some frequencies being emphasized or muted do to aged caps or other drifting components. This is one thing that I noticed had improved dramatically after the recap. The sound stage was much more "locked in". Vocals no longer wandered and in one particular song which is a duet, the vocalists were in distinct places very close to each other but not occupying the same space as it was before the recap.

The other noticeable change was the overall balance from top to bottom. They are no longer "bright" as they were before the recap. There is a much better balance to the point that I now run the mid, EMIT and SEMIT at their factory nominal settings. I suspect this may be why vintage Infinitys are often criticized by some as being a bright or harsh speaker. Recapping the woofers, mid bass and part of the polydome section has "restored" the original output levels to those drivers. This phenomenon, in my experience, is not unique to the 9s only. I have done electrolytic-only recaps of my Kappa 8s(as mentioned in my earlier post), Kappa 6s, RS5bs and RSIIIbs. In each case the same restoration of the lower range brought up the level to match the upper end. It was most dramatic with the RSIIIbs, likely do to them being the oldest of the group. I believe those who find vintage Infinitys bright or harsh might have a different opinion if they have a chance to hear some that have been "restored".

During the time between my last post and this summation I have also had a chance to listen to the 9s with a different amp setup. I acquired a Sunfire 300 amp which is now a permanent part of the system. Originally I was using a pair of Onkyo M-504s. I first used the Sunfire by itself and it certainly is up to the task of driving these speakers effortlessly. One interesting thing to note. Those of you familiar with the Sunfires know that they have different output options to mimic different amp "sounds". One being a tube-like sound. I tried the bi-wiring setup with the "transistor" output to the woofers and "tube" output to the mids/highs and personally I did not care for it at all. There was just no "life" in the the top end. I tried several different configurations. I really like the "transistor" sound with the woofers, it is much better at controlling them than the M-504, not that it did a bad job. I still favor the M-504 on the top end so the final configuration is the Sunfire for the woofers and one of the M-504s for the top (until something interesting comes along to try).

In summation, these are speakers I will likely never part with (unless a reasonably priced pair of Betas appeared on my doorstep). I've had a chance to listen to speakers that cost 10 times more than even an auction inflated pair of Kappa 9s that struggle to do what the 9s are capable of.

 

[7.62]

Thank you siefriet for sharing with us, I was hoping to read a review positive like yours . I believe I’m in the same boat. I’ve been through a bunch of infinity’s and I just don’t see these ever leaving my possession.

I am watching eBay for a pair of crossover’s, I’d like to open them up and do some light modifications moving the coils so they minimize crosstalk and maybe follow you in changing some caps but keeping my original crossovers as they are just put away.

I thought mine were bright but playing with positions and dialing back the pots seemed to have eliminate that.

I managed to put my HK 745 in shut down mode yesterday listening to some GZA Liquid Swords, it also showed I have one woofer that’s buzzing I’m so going to remove it and try a refoam this weekend. The previous owner did them recently and looking through the dust cap I can just see where it’s cocked to one side. Hopefully I can get it right with a test tone.

Anyway I’ve really enjoyed your journey, Thank you for sharing with us again ! I’ll be referencing this. These 9’s really are special.

 

[jazzmans]

Thanks @7.62 . To answer how they sound,

Part 6 - Final impressions and thoughts

I apologize to those of you who have been waiting for this last installment to my RS 9 Kappa journey. Here are a few thoughts I have on the overall sound and some things I've learned.

I wanted to wait for some period of time to allow all the changes, new caps and EMIT diaphragms, to settle in before making any final judgments. As with any speaker "evaluation" these are my impressions, your mileage may vary.

When I first got the 9s I was very impressed by their overall sound. They did appear to be a little bit "bright" so I ran them with the polydome, EMIT and SEMIT controls down a bit. I also had trouble locking in on vocals in particular. They seemed to "wander" across the sound stage. I had read about this phenomenon and some attribute it to a mismatch between the crossovers, some frequencies being emphasized or muted do to aged caps or other drifting components. This is one thing that I noticed had improved dramatically after the recap. The sound stage was much more "locked in". Vocals no longer wandered and in one particular song which is a duet, the vocalists were in distinct places very close to each other but not occupying the same space as it was before the recap.

The other noticeable change was the overall balance from top to bottom. They are no longer "bright" as they were before the recap. There is a much better balance to the point that I now run the mid, EMIT and SEMIT at their factory nominal settings. I suspect this may be why vintage Infinitys are often criticized by some as being a bright or harsh speaker. Recapping the woofers, mid bass and part of the polydome section has "restored" the original output levels to those drivers. This phenomenon, in my experience, is not unique to the 9s only. I have done electrolytic-only recaps of my Kappa 8s(as mentioned in my earlier post), Kappa 6s, RS5bs and RSIIIbs. In each case the same restoration of the lower range brought up the level to match the upper end. It was most dramatic with the RSIIIbs, likely do to them being the oldest of the group. I believe those who find vintage Infinitys bright or harsh might have a different opinion if they have a chance to hear some that have been "restored".

During the time between my last post and this summation I have also had a chance to listen to the 9s with a different amp setup. I acquired a Sunfire 300 amp which is now a permanent part of the system. Originally I was using a pair of Onkyo M-504s. I first used the Sunfire by itself and it certainly is up to the task of driving these speakers effortlessly. One interesting thing to note. Those of you familiar with the Sunfires know that they have different output options to mimic different amp "sounds". One being a tube-like sound. I tried the bi-wiring setup with the "transistor" output to the woofers and "tube" output to the mids/highs and personally I did not care for it at all. There was just no "life" in the the top end. I tried several different configurations. I really like the "transistor" sound with the woofers, it is much better at controlling them than the M-504, not that it did a bad job. I still favor the M-504 on the top end so the final configuration is the Sunfire for the woofers and one of the M-504s for the top (until something interesting comes along to try).

In summation, these are speakers I will likely never part with (unless a reasonably priced pair of Betas appeared on my doorstep). I've had a chance to listen to speakers that cost 10 times more than even an auction inflated pair of Kappa 9s that struggle to do what the 9s are capable of.

I'm surprised you didn't like the sunfire with the mids/highs wired to the 'tube' like output, and the woofs to the 'transistor'like output. I've read (never did get to hear) multiple reviews that really liked that combination.

Oh, and I'm jealous you scored a sunfire. Fantastic amps.

 

[seifreit]

I'm surprised you didn't like the sunfire with the mids/highs wired to the 'tube' like output, and the woofs to the 'transistor'like output. I've read (never did get to hear) multiple reviews that really liked that combination.

I was surprised that I didn’t care for that combination either. I’ve read countless posts regarding how Arnie voiced them with transistor amps for the woofers and tubes up top. When I first hooked up the Sunfire with that combination I was expecting an out of body experience. I listened to that setup for a couple weeks hoping it might get better but the top end just seemed too soft, dull.

I used to be one of those who felt an amp was an amp and it shouldn’t make a difference to how a speaker sounded as long as it could provide clean adequate power. This is the first time I’ve had an opportunity to listen to different amps with a pair of high quality speakers that can reveal those differences. Very eye-opening. I would really like to try a true tube amp for the top but it’s not in the budget at the moment. Until then, I’ll just keep enjoying the current setup.