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Gaining Speakers, While Losing My Mind!


frankmarsi

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Ha! - great sense of humor, Frank!

AR-LSTs and AR-9s for home theater effects would be like using a Corvette to pull tree stumps. :)

More like using an Abrams M1-A1 tank to pull stumps. ;)

Still willing to take anyone's unwanted pair of AR9s off their hands.

MetroWest MA

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2-13-14 5:33 EST *Follow-Up

Yesterday, I spent about four and half hours doing dry rot foam removal duties.

I decided to operate slowly as I almost wanted to savor working on these AR-9 speakers. This being my first time with this model, I decided to enjoy the whole dismantling of each driver from the cabinet. I knew this wasn't going to be a quickie two woofer job.

As I reported in a earlier post I had found at least a couple woofer screws were loose, upon fully removing the four woofers I found in total another 6 or more screws that were loose.

I’ve never found a single screw loose in the many times I had re-foamed my AR-3as and LSTs. Not that this matters at this point of course, but it was somewhat disconcerting to see this in an AR speaker. It must’ve been the smaller screws I mentions earlier. I wish AR had used the bigger heavier ones instead.

Once again peering into the open hole and seeing the complicated cross-over was a little overwhelming. I realized that at some point I may have to replace a few capacitors and such, it was an unsettling thought.

After removing the six drivers I set them aside in the order in which I removed them so as to be able to re-install them to their the same positions. I figured perhaps these drivers being untouched for over 36 years, may have ‘married’ much like gears do in a gear box? I set everything aside in order and retired for the evening.

Today, I began the woofer re-foaming process. I was too excited to delay the task.

I went after the woofers first, doing one set at a time along with the lower-mid. It was easier not having the screens on the woofers as the 3a and LST do, it was so much easier to work on each one.

The whole re-foaming process for all six drivers took a little over four and half hours and that included eating a chunk of provalone and half a loaf of Italian bread. Not bad, but then again I had previous experience from the other speakers in my stable. I went a little slower with the lower midranges though. They seem so frail compared to the woofers.

Holding myself back from re-installing them in their cabinets today, just to insure a complete drying of the glue over-night. I was so anxious to hear them for the first time but, I knew if I did play them tonight I would probably be tempted to push them and that would dumb.

Here in Jersey, I’m literally ‘snowed-in’ and have enough food on hand to spend another day just playing with them, I’ll enjoy myself then.

Tomorrow, I’ll set-up a pre-amp, amp and CD player and give a listen.

I’ll report back with the results then.

fm

P.S. In my typically lazy fashion I bought a can of “Pledge” New- Extra-Moisturizing spray. You know it actually worked pretty well with two applications, they look more than acceptable, and they smell so nice now. Doing this only made them even more mine!

Tomorrow, I apply a couple of more coats of the ‘Pledge’ and I’ll pretty much stop there as I’m not about to get crazy with restoring the finish. These things are not new and have a certain patina indicating their age, just like I do, so I’m O.K. with that.

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I'll be looking for a post from you first thing tomorrow morning. I am very curious about what you will think of them.

I really think you should at least replace all the small black caps. Some of the caps in my 9's were not in good shape. It is not overly difficult if you just do one at a time.

Harry

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2-13-14

I couldn’t put-off till tomorrow what I was able to do today.

I assembled one cabinet with all the completed drivers.

I left the second for tomorrow cause it’s components were the

ones finished last and probably needed more time to dry.

While I still had some energy left, I proceeded to give both cabinets two more applications of the ‘Pledge’ spray.

I sprayed certain areas more than others because it seems these boxes have

a very dry veneer and wood is unpredictable that way. I let the liquid set for a few seconds and then rubbed it in along with the rest of the area.

It turned to all look very good and I still stand by my original assessment

about these speakers and feel the are in excellent condition.

The only difficulty that was experienced while doing the re-foam operation was the old adhesive that was on the outer rim of the woofer’s basket. In particular where the black foam dressing was original installed, it left an ugly and extremely sticky residue behind.

I tried number of different methods; liquids,(didn’t have any acetone), scraping tools and time, but nothing worked well enough. Consequently, it looks horrible and has an unsightly and uneven surface.

This guy may have a possible answer: http://www.audiokarma.org/forums/showthread.php?t=396437&page=6

I ended up painting the outer rim with flat black paint and it now looks my older AR-3a woofers.

So, has anyone any info regarding sources for the black foam insets that would cover that outer rim? I have a feeling there will be none out there.

It may be a good idea for some one to market them?

Updates to follow. Oh gee.

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Frank, you might give Bill LeGall @ millersound a call (215 412-7700)

He should have a good source for that cosmetic foam trim for your woofers.

The woofer screws might have been loose for a number of reasons - any chance the T-nuts weren't fully embedded in the particle board?

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So, has anyone any info regarding sources for the black foam insets that would cover that outer rim? I have a feeling there will be none out there.

It may be a good idea for some one to market them?

I made them myself, used exacto knife and scissors to cut them from computer mouse pads.

I have peeled off the top plastic layer with pretty pictures! :)

Before and after:

79195273.jpg

57168687.jpg

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Regarding millersound's reply:

Quote:

Hi Frank,

We don't sell it, but use black non-backed cabinet covering, as used in the world of commercial sound. It looks great, works beautifully into place and doesn't require precision-cutting. Cut this into 3/4" wide, long strips. As you glue it in place, it will narrow-down from 3/4" depending on how much you pull it. That's why it's so great. Never rots!

Cheers,

Bill

End of quote.

FM here: ar_pro, I don't understand what he means?

FM here: HarryM, I've must admit I've read that I should, but I'm going to try them first and see. I've never changed a 'cap' in any of my speakers, maybe I'm missing something that I'm not aware of? Like better sound I presume, if it is that discernable, is it?

FM here: Kuja, I've never been good with a scissor and circles, no seriously. The idea mentioned earlier with the knife and wallboard cutter seems more accurate.

The speakers are done and I must say I’ve done a wonderful job in terms of bringing back to a higher degree from the actual condition I received them in.

I’m very pleased.

Now I have to move them and do a temporary hook up and initial listen test. That’s the problem; I won’t try to move them by myself, is that too weak of me?

Wish me luck.

I wanted to post a foto, but there's so much crap in the room with them, I will when I move them.

I’m going to look for two large plant wood dollies at one of many the garden centers here, if I can get out tomorrow. This snow crap really sucks, enough already.

fm

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Frank

First of all, if you got a reply from Bill you're talking about Millersound, not M Sound (similar names but different guys).

Not real sure what he is referring to (black non-backed cabinet covering). I thought pro speakers were covered with carpet-like material or Tolex. But it sounds like Bill is doing essentially what Kuja did. However, the gasket serves no purpose and you can leave it off. Note Madtech refers to it as "the black cosmetic ring".

Caps OTOH DO serve a purpose. Electrolytic caps last 2 or 3 decades, then start to drift (changing the xo points), leak or worse. Those old PVC caps (black with red ends) are notorious for leaking and even cracking. I've posted the photo below before. It's a KLH Seventeen xo that uses the SAME PVC caps found in the AR-9. If you go back to the AK thread you referenced, the silver can caps are probably fine but I'd definitely replace the black/red ones (AK post #31).

Just my $0.02...

Kent

post-101828-0-24016900-1392434194_thumb.

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I've fallen and I can't get up!

2-15-14

Having completed the assembly of the drivers yesterday and having replenished the wood surfaces, I was feeling proud as they do look great.

But, quietly staring at them, I pondered the necessity of changing the capacitors before I hook-up them to an amplifier.

Reading several posts here and elsewhere, a note of fear had entered my mind.

It seems obvious; the common wisdom expressed here is to do this necessary step now.

At the risk of sounding lazy and even more so, incapable, I’d like to ask if someone with AR-9 experience would come forth and post a list and an actual (layman’s) schematic, so that I could order the capacitors swiftly and get to the completion of these speakers. Any recommended supplier of these components would be helpful too.

I’ve seen “xmas” has printed a list of caps here, but it doesn’t open on my Mac computer.

From what I can hardly recall from many years ago, some caps have polarity, some don’t, so in the schematic needed, it would have to illustrate the direction of installation.

I also have checked out inexpensive meters, but how much use would I get out of owning one in the long run? Not that my limited knowledge would really benefit either. In essence, I’m a novice at this point.

So, on my bended knee, I’m asking for a list of components and instructions for replacing the capacitors that must be replaced and if some could stay with out replacement that would be good too.

Sorry to come across as such an incompetent and wimpy AR person!

It’s just the thought of burnt tweeters and to stupidly take a chance at harming these speakers is obviously not the way to go.

I thank anyone who is kind enough to post what I’m looking for.

fm

http://www.audiokarma.org/forums/showthread.php?t=396437&page=10

P.S. As long as I'm going back into these boxes, any recommendations for binding posts that have been used by members?

P.S. Thanks rjr513, your link is just what I need.

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I have not worked on the 9 and as I understand it the schematic in the Library may not be 100% accurate.

IMHO you should consider replacing just those black/red caps. One way to be sure you get the right ones is by checking what's in there now.

But a couple of general points:

  • You are correct that some caps have polarity but you should use only non-polar caps in a speaker xo
  • Use film caps for smaller values. You can use NPEs (non-polar electrolytics) for higher values.
  • Erseaudio.com is a good source. So is Madisound.
  • Don't worry about voltage. Modern NPEs will be higher voltage rated than the originals and film caps will be WAY higher. This is good.
  • You can be off by up to 10% on the uF. For example, a 4.7uF is a perfectly good replacement for a 5uF
  • You can wire caps in parallel. For example, I think there is a 24uF in your 9. If this needs replacement one option would be to use two Madisound 10uF and two 2uF "surplus" caps. Or any other combination that adds up to ~24uF
  • Madisound Carli caps are a good choice: Economical and, according to Roy, their ESR is close to that of the original NPEs.

Hope that's helpful.

Kent

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Sorry Frank, I thought I had good pictures of the xovers but I don't. From the pictures I do have it looks like there are 4 black and red caps on the xover on the back of the cabinet only, non on the bottom. I removed both woofers and laid them on their backs. It is a little clumsy to work on but not bad.

Harry

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http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=6354

http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=7567&page=2

http://www.audiokarma.org/forums/showthread.php?t=396437

O.K. I’ve read these sites today and to be honest it seems as though my goose is cooked and I will have to do the ‘re-cap’ thing.

I'd like to think that I may be able to at least try these speakers out first?

Spending a total of nine hours re-foaming, about another hour or so feeding the dried looking veneer and just feeling so excited about these speakers is now

really sitting on the back burner.

Some questions:

What if beyond most opinions expressed, I wonder what they would sound like before a 'cap' change?

What if they are with in the limits of their specifications?

I've done more reading about these speakers than I've actually spent trying to listen to then which has been no time at all.

Now I must order some capacitors, tear out the woofers again and begin another long anxious and tedious journey.

Another question that no one has addressed in any of the above links is fusing.

I'm thinking of taking a peice of 1x4inch piece of wood with a fuse block mounted on it. It could lay on the floor sitting behind each enclosure?

I'll ponder that waiting for the 'caps' to come even if I haven't ordered anything.

Unless I have the good fortune of some one posting a list of components, me thinks, I 'll have to open them up again and draw diagram of the location and value of each component.

There seems to be a problem I've read about the schematic that there's a 'cap' being slightly different than the actual value of the 'cap' installed at the factory is still a concern of mine.

If anyone has an accurate list of values, please pass it along. Thanks.

Over-all I'm pretty much experiencing major let-down right now.

These speakers were an ordeal before I got them in my hands and now continue to be so as I was hoping they'd be 're-foam and play'.

Perhaps my rewards will prove differently in the future? Right now one could call it very anti-climatic!

fm

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Just the messenger here - - - am unable to vouch for any of this, but attached is some very specific information regarding cap values, brands, and prices that xmas111 used in one of his AR-9 re-builds. This info was found in the spreadsheets (contained in zipfile) from his AK posts from May and June 2012, even though the pricing is even more recently dated as Nov 2012. Have not reviewed this closely, but it appears he replaced all of the capacitors in these speakers (see 1 thru 9 on schematic and price list).

post-112624-0-91906100-1392506679_thumb. post-112624-0-42981300-1392506723_thumb. post-112624-0-43150900-1392506741_thumb.

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Dear ra.ra, my hero!

While I was wallowing in self-despair, you like the night in shining armor come strolling in the door.

Yes! Maybe the AR gods haven’t abandoned me?

Thanks, I printed copies, tell 'xmas' thanks. No, I'll tell him.

Thanks xmas.

One question is; must I replace the two 'caps' listed at the top of the list of #s, 1&2?

There seems to be varying opinions regarding these two, the biggest of the group, some feel they’d still be usable in place with no need to change them.

Looking at the prices, is there a lower cost brand with out sacrificing any quality or longevity?

Many peeps seem to like the Dayton, P.E. parts better and save money that way?

Is it safe to assume these values are +or – 10%?

Would you or anyone else know the equivalent size of 'allen-head' screws for the woofers?

I'm done with the original ones, they're wearing out already, besides the 'allens' would look better and last longer.

I’m so excited, I want to order them right now! But I’ll shop around first.

I’ll also linger for a while and see if any other comments come thru the door.

Thanks mucho, ra.ra

fm

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Sheesh, what a difference a day makes. Yesterday, I was feeling a bit irked by this discussion, thinking that perhaps you had succumbed to a severe bout of irrational high-end hoarding, which has been known to sometimes infect graduates from the Garden State School of Chris Christie Overconsumption. But today, I am the hero, and I like this perspective much better. Perhaps my temporary transformation to Grumpus Maximus was due to the lightning bolts emanating from my lower back, courtesy of w--a--y too much snow shoveling.

First, ultimate kudos must be paid to xmas111, who sometimes goes by the anonymous alias "John". His speaker (and turntable) restoration work is at or near the very best and most thorough re-construction projects I have seen on these, or other, pages dedicated to vintage audio. That said, there are many here (not me, not John, not you) on the CSP forum who are far more knowledgeable to consult on matters of capacitor testing, analysis, and replacement.

Your questions, however are spot-on regarding the hierarchies of cap replacement. For anyone to be able to assist in greater detail, you really should try to post pics of your particular circuitry. With this information, the informed experts can then chime in with explicit prescriptive measures.

Many have stated that the larger aluminum "can" caps very often remain close to their original values, even after 40+ years, so your thoughts about maybe retaining the 1 and 2 caps (and possibly even the 3 and 4?), are indeed astute questions. All of the better purveyors (Erse, Madisound, PE....) routinely post the basic specs on their websites, so you can always evaluate the expected tolerance, and perhaps sometimes more importantly, begin to understand the size and physical limitations involved with replacing some relatively small NPE caps with normally much larger film capacitors. Regarding cost value, I happen to embrace the advice I get from Roy and Kent (and others) here who tend to eschew the temptation of expensive boutique caps, and instead try to direct restorers toward far less expensive choices which function perfectly well. Sound advice.....pun intended.

Finally, I am not familiar with the details of AR-9 cabinet construction, but I suspect that t-nuts are used to accept the driver mounting screws. However, most any good hardware store should be able to match your screw's length and thread size if you provide one to 'match'. Last word: do not rush things - - - take just a little time to shop, research, and get familiar with some of the options available to you (caps, foams, cabinet finishes, etc) .

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Frank,

The first speaker I ever recapped were a pair of AR90's. I could barely use a soldering iron, and had never seen a capacitor before. But the speakers turned out beautifully- my daughter got them from me when I got my AR9's. I've done several speakers since, including my 9's. I got all the information I needed to do it from this forum.

What I did was clip off the old capacitors near the body, then twisted the wires together with the new ones. A little solder and your done with each one. I found the AR9's considerably easier than my 90's. The bottom crossover is easily removable, and the bigger woofer holes make the upper easier to reach. Just take your time and use plenty of light.

If I can do it, you can too. Good luck.

-Joel

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Hi frank, this is a list & price of the caps I replaced. But I'm in the uk so prices may be cheaper in the US. I'd like to hear others opinions if they think they are ok & I had the 8uf cap in mine Not the 6.

Electrolytic/ClarityCap -

2 x Alcap 80uF 100V 2% tolerance £2.54 ea.

£5.08

2 x Claritycap ESA 250V 30uF 3% £19.00 ea.

£38.00

40uF 3% £22.25 ea. £44.50

24uF 3% £18.60 ea

£37.20 ( supplied as 2 x 12uF)

6uF 3% £6.20 ea. £12.40

4uF 3% £5.00 ea. £10.00

8uF 3% £7.82 ea. £15.64

VAT

£32.56

Total

£195.36

I hope this is helpful.

Regards

Matt

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Another question that no one has addressed in any of the above links is fusing.

I'm thinking of taking a peice of 1x4inch piece of wood with a fuse block mounted on it. It could lay on the floor sitting behind each enclosure?

[. . .]

There seems to be a problem I've read about the schematic that there's a 'cap' being slightly different than the actual value of the 'cap' installed at the factory is still a concern of mine.

You may have already located the AR-9 Owner's Reference Manual, but if not, you can find the recommended method for fusing, therein:

post-101656-0-14639000-1392554321_thumb.post-101656-0-36405100-1392554338_thumb.

For a high-resolution downloadable copy of the full manual (courtesy of CSP member passport), see below:

AR9 Reference Manual, high quality scan, one PDF file

Regarding the 8µF cap in parallel with the upper midrange, my understanding of how the (is-it-a-6-or-an-8) ambiguity arose is detailed in the following thread:

The mystery has been solved

In my opinion, the caps referenced in xmas111's list above, as #5, are not the correct value. As ever, I would reference what you have in your AR-9 (assuming that they are original components), before proceeding.

Robert_S

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Just the messenger here - - - am unable to vouch for any of this, but attached is some very specific information regarding cap values, brands, and prices that xmas111 used in one of his AR-9 re-builds. This info was found in the spreadsheets (contained in zipfile) from his AK posts from May and June 2012, even though the pricing is even more recently dated as Nov 2012. Have not reviewed this closely, but it appears he replaced all of the capacitors in these speakers (see 1 thru 9 on schematic and price list).

attachicon.gifAR-9 xover.jpg attachicon.gifAR-9 schematic.jpg attachicon.gifAR-9 caps price.jpg

The schematic shows a 6uf cap in the upper mid circuit. It should be 8uf.

Roy

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Rob, thanks for posting that info. I had forgotten all about that excel file.

I did replace ALL the caps when I did both sets of AR9's. The worst part of the job is getting the crossover borads out of the cabs.

Luckily I still have the excel file with all the info. I updated the 6uF to 8uF in the upper mid like Roy mentioned.

I did use 8uF caps when rebuilding the 9, I just never updated the excel file.....sorry about that! :rolleyes:

Checked all the prices and there still the same.

I can't attach the file here, CSP doesn't allow that type file to be uploaded.

I put a copy on my server and you can get it there if you like.

John

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O.K. fellas, you've all be very helpful, I thank you all for your efforts and advice!

I guess I'll be ordering from P.E. just not sure which brand name, etc. I don't think I have to buy the costly ones?

I could do the wiring if I wake up, take my time and put my little mind to it.

In the mean time check this out.

You see by having the AR-9s now, its going to force me to make another level using my third set of LSTs, otherwise there's no more room in the house.

I'll just stack them in the corner, no one will see them?

fm

P.S. This is not my equipment shown here. And these Amati's can't sound good stacked in the middle of the room like that as they need to be against the front wall.

 

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Happy to hear that this mystery has been solved and confirmed.

Not sure at all where this particular document came from (could it be yours, John?) - - - I found it in my "downloads" folder - - - but it, too, seems to suggest that the mystery cap on the UMR (in red) was mis-identified in original AR material. Of greater interest perhaps, for current and future AR-9 restorers, is to note just how far from original spec values virtually all of these capacitors have drifted upward (in blue). Is it actually possible that the LMR capacitor values had actually doubled when measured?

This is not my data - - - just a document I found while doing some online reading and research. Normally, I like to attach easy-to-access jpeg files, but I was losing too much detail when trying to convert, so I include it here as a pdf file.

Actual_AR9_crossover_circuit.pdf

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