AR6 and AR91 Capacitor

[Guest Sweden]

Hi all,

(this is a "continuation" of the thread about what a reasonable price for AR91 would be.)

AR6:

As the ones that have followed the above thread, I'm experiencing a strange sound-issue with all my 4 speakers where there is a scraping sound on certain freqs. On of the repliers suggested it might be the capacitor. So I opened my AR6 today and looked inside and found a quite big, light-blue battery-shaped capacitor with the name Sprague on it. It was hard to read out anything more since it was glue all over the cap. The cap looked fine, nothing looked burned or leaked.

I did a simple search on the net and found several sellers of vintage caps, but none would just sell 1-2 caps to a private person.

So how should I proceed?

Perhaps I should measure the cap first? How do I do that?

AR91:

What can I expect when I open up the 91? How many caps should there be in one speaker? If more than one, which usually wears out?

Thanks

Rickard

[Guest dogmeninreno]

>Hi all,

>

>(this is a "continuation" of the thread about what a

>reasonable price for AR91 would be.)

>

>AR6:

>As the ones that have followed the above thread, I'm

>experiencing a strange sound-issue with all my 4 speakers

>where there is a scraping sound on certain freqs. On of the

>repliers suggested it might be the capacitor. So I opened my

>AR6 today and looked inside and found a quite big, light-blue

>battery-shaped capacitor with the name Sprague on it. It was

>hard to read out anything more since it was glue all over the

>cap. The cap looked fine, nothing looked burned or leaked.

>

>I did a simple search on the net and found several sellers of

>vintage caps, but none would just sell 1-2 caps to a private

>person.

>

>So how should I proceed?

>

>Perhaps I should measure the cap first? How do I do that?

>

>AR91:

>What can I expect when I open up the 91? How many caps should

>there be in one speaker? If more than one, which usually wears

>out?

>

>Thanks

>Rickard

Rickard, Something strange is going on here. The "scraping" sound as you describe it is transfering to other amps and speakers which is really unusual. what is the voltage and Hz of your utility supply? 220V 50Hz or 120V 60Hz. This seems remote since your problem is after several minutes but may be relevant. Dale

[Guest Sweden]

>>Hi all,

>>

>>(this is a "continuation" of the thread about what a

>>reasonable price for AR91 would be.)

>>

>>AR6:

>>As the ones that have followed the above thread, I'm

>>experiencing a strange sound-issue with all my 4 speakers

>>where there is a scraping sound on certain freqs. On of the

>>repliers suggested it might be the capacitor. So I opened my

>>AR6 today and looked inside and found a quite big,

>light-blue

>>battery-shaped capacitor with the name Sprague on it. It was

>>hard to read out anything more since it was glue all over

>the

>>cap. The cap looked fine, nothing looked burned or leaked.

>>

>>I did a simple search on the net and found several sellers

>of

>>vintage caps, but none would just sell 1-2 caps to a private

>>person.

>>

>>So how should I proceed?

>>

>>Perhaps I should measure the cap first? How do I do that?

>>

>>AR91:

>>What can I expect when I open up the 91? How many caps

>should

>>there be in one speaker? If more than one, which usually

>wears

>>out?

>>

>>Thanks

>>Rickard

>Rickard, Something strange is going on here. The "scraping"

>sound as you describe it is transfering to other amps and

>speakers which is really unusual. what is the voltage and Hz

>of your utility supply? 220V 50Hz or 120V 60Hz. This seems

>remote since your problem is after several minutes but may be

>relevant. Dale

Hi Dale, in Sweden we have 220V and 50Hz.

Rickard

[Guest Bret]

>So I opened my AR6 today and looked inside and found a quite big, light-blue battery-shaped capacitor with the name Sprague on it.<

First, let me be sure you understand that my even mentioning the capacitors was groping in the dark for an answer to a very strange situation. I don't *think* it's capacitors. I was just searching for *any* explanation.

The AR-6 and the 91 are of differing eras, with different crossovers, designed by different people, with different parts, and so it would also be highly unlikely that each capacitor of two unlike pairs has gone bad. Compound that with your getting the exact same symptom out of 2 pairs of different tweeters. . . well, I wouldn't put a dollar on a 100:1 bet.

I think you should investigate other possible explanations very thoroughly.

One obvious one comes to mind -> It's taking some component in your system a few minutes to start making this noise. OR alternatively, the noise has always been there and the AR tweeters are just good enough that you can hear it now.

Frankly, I think it's far more likely that two CD-players have the same problem than that the capacitors have all gone bad producing exactly the same problems.

Bret

[Guest Sweden]

>>So I opened my AR6 today and looked inside and found a quite

>big, light-blue battery-shaped capacitor with the name Sprague

>on it.<

>

>First, let me be sure you understand that my even mentioning

>the capacitors was groping in the dark for an answer to a very

>strange situation. I don't *think* it's capacitors. I was

>just searching for *any* explanation.

>

>The AR-6 and the 91 are of differing eras, with different

>crossovers, designed by different people, with different

>parts, and so it would also be highly unlikely that each

>capacitor of two unlike pairs has gone bad. Compound that with

>your getting the exact same symptom out of 2 pairs of

>different tweeters. . . well, I wouldn't put a dollar on a

>100:1 bet.

>

>I think you should investigate other possible explanations

>very thoroughly.

>

>One obvious one comes to mind -> It's taking some component

>in your system a few minutes to start making this noise. OR

>alternatively, the noise has always been there and the AR

>tweeters are just good enough that you can hear it now.

>

>Frankly, I think it's far more likely that two CD-players have

>the same problem than that the capacitors have all gone bad

>producing exactly the same problems.

>

>

>Bret

Bret, I agree with what you say. 4 out of 4 is strange.

OK, if we discuss the potential sources that could be the problem, I have done the following:

- Played a record that causes the scraping/crunching sound on three other CD-players, 2 in the same appartment 1 one portable. No scraping sound elsewhere.

- Changing AMPs, I borrowed a NEW ARCAM AVR 200. The same sound occured and this after a few songs.

- Switching between CD-players.

- Switching off the equalizer (the stereo equalizer).

- Switching between speakers.

- Changing the switches on the back of the speakers to all positions/combos.

- Visually investigate the tweeters, and I can assure you that they look beatiful, there is no cracks, burned stuff or whatever. The cables seems fine as well. Both pair of speakers have been extremly gently treated (collectors items). I can assure you that the AR6 has never been played loud. They have been rarely played. They belonged to my wifes parents and they didn't play music that much.

- Played other records, that works just fine, no evidence at all of the sound-issue. If it was a broken tweeter, I guess I would hear it all the time. At least this is my experience from previous broken speakers.

- Both speaker-pair sounds beatiful!!!

So have I ran out of options yet? NO, I will do the following:

- I will listen again to see if the problem occurs after a few songs. I have tested this 3 times, but I will test this again on both speakers. I.e. start with a cold amp ant the AR6 and then have the same procedure for the AR91.

- Bring the AR6 to a local shop and listen to a DENON 3805 using several of my own records, of course some of the bad boys. If the problem is gone. BINGO, an environmental problem. If the problem persists, it must be something with either the speakers or the records (CDs).

- Try the same CD using the shops equipment. If a sound-issue, then the CDs are bad and I will have to live with it. If no sound-issue, then it must be the speaker.

- If the speaker, the next step would be to ask someone to help me measure the filter and such to see that it, unbelievable or not, could be an aging problem.

- If everything looks ok, then the last step is to buy a cheap tweeter and connect it to the speaker and just test to see if that tweeter has the same scraping sound. If there is still a scraping sound, then I don't know what it is, perhaps still the caps eventhough they measured fine. If no scraping, then it is probably the tweeters I guess?

(At the very bottom of my TODO-list is replacing parts, esp. drivers. Perhaps I will just live with it as long as it not destroys the drivers or the amp.)

Sorry for the rambling

Thanks

Rickard

[Guest Bret]

>Sorry for the rambling<

You didn't ramble.

It looks to me like you have a perfectly reasonable plan of action.

Let us know what you find along the way.

Bret

[Guest Sweden]

Yes, I will keep y'all posted.

I have just been in contact with the local DENON-dealer and they welcome me to bring my AR6 to them and listen. I will do that next week.

I described my problem to them and they had two ideas:

- Remove the antenna-cable. It's obviously a known problem that the antenna can cause some distortion and my stereo is connected via the DVD to the TV. I will try this today.

- The tweeters are actually burned, but only so much that it's on the very highest freq it appears. But you guys seems to think that this is unikely? Can someone please tell me if they have ever experienced a blown AR-tweeter that works for more of the time, but not on the highest freq?

Thanks

Rickard

[Guest Sweden]

I performed some tests yesterday and I have some interesting findings to share.

I started to remove the antenna-cable, took the badest CD of them all, and listened. This time focusing real hard to hear if the problem now would disappear and if not, when it occurs and how it sounds. The problem didn't disappear and it started with that some of the freq. couldn't be "carried". Instead of a crystal clear tone, it was scattered. This was a bit hard to hear from a distant, but when standing close to the speaker, it could be heard. The scattering effect came even on low volumes. Then after some minutes, the familiar crunch came (the scattered sound is still there). To conclude, there is evidently a sound-issue immediately, it was just a bit hard to hear when it wasn't the crunch from the start!

So this was of course a disappointment that the antenna wasn't it.

So I thought hard and I decided to go back and do some re-tests. Sometimes when I have a problem, I can go forward to fast and perhaps I had missed something?

I decided to check out the signal source again, this was a tip from one of you guys, and I took some old vinyls and listened hard. It's quite hard to determine if there is a "vinyl-crunch" or the "problem-crunch" but I more and more believe that it is a "vinyl-crunch" (yes my old LPs have been played a lot...).

I thus think that the problem isn't there after all when I play a LP. I played the same song on a LP that I have on a CD and it wasn't any sound-issue on the LP but on the CD. I played a LP with a lot of flute, no problem at all. I played a CD with a lot of flute. The sound-issue appeared.

I think it was Bret suggesting that both my CD-players could be the cause and I'm bound to agree with him. I guess that an explanation could be that the CD-players aren't that good and that they don't send out some freq. that are on a CD and that this can cause the speaker to reproduce it as a crunching and scattered sound?

Anyway, the next step is still to bring my speakers to the local dealer and listen to the DENON. I guess that a new DVD will be auditioned as well.....

Hold your thumbs guys that this is the explanation!!!!

Thanks

Rickard

[Guest Bret]

Rickard,

I thought I had mentioned this before, but since it appears I didn't mention it to you:

>The tweeters are actually burned, but only so much that it's on the very highest freq it appears.<

It is entirely possible to have a tweeter that plays that is also ruined. I used to believe that a speaker driver was much like a lightbulb; that is, if it played, then it was good.

I have learned that I was wrong.

What I have not learned is how to test for this condition except to listen to a known good tweeter compared to a bad one. Unscientific, yes, but it seems to work.

Bret

[Guest Nigel]

>I think it was Bret suggesting that both my CD-players could

>be the cause and I'm bound to agree with him. I guess that an

>explanation could be that the CD-players aren't that good and

>that they don't send out some freq. that are on a CD and that

>this can cause the speaker to reproduce it as a crunching and

>scattered sound?

>

Hi Rickard;

You have not told us much about your CD players, but what you described could be caused by them.

Further experiment suggestions:

1. cold amp, with warm/hot CD player.

2. warm/hot amp with cold CD player.

[Guest Sweden]

Hi Nigel,

thanks for your suggestions.

A friend of mine will bring his CD-player over and we will test with his equipment and see if this makes any difference. I will start with that. Then I will bring my AR6 to the local dealer and test with their stuff.

The things I find strange are the following:

- The problem sounds exactly the same on all 4 speakers, this on the exact same songs and parts of songs and instruments. Flute, violin, guitar (punk and metal).

- When playing a vinyl, the above instruments doesn't create this sound-issue.

The above two things is my "hopes", i.e. my hopes that it is my CD or DVD causing the problem. But I wouldn't be surprised if all the 4 tweeters have gone bad in the exact same way over the years.

My DVD is a Pioneer 343. I've had it for 2 years. It has started to behave strange in other ways, it opens the tray and can't read some records on the first try. I have tried to clean the laser, but the tray-problem is still there. Otherwise, it works fine.

My CD is a Fisher Studio Standard from -86. It has no known errors. We just replaced it when we bought the DVD.

Neither of them are top of the line stuff.

Rickard

[Guest Sweden]

Bret

>

>What I have not learned is how to test for this condition

>except to listen to a known good tweeter compared to a bad

>one. Unscientific, yes, but it seems to work.

>

This will be my last test and I hope I never get to this point. I'd rather hope that it is my CD or DVD-player. I don't know if a CD better exposes a tweeter-problem than a vinyl? (see my reasoning in the response to Nigel)

But if it is the tweeter, I will try to find a reasonable similar tweeter and just connect it and see what happens. The problem (again) is to find AR-components in Sweden so therefor, I think I need to settle with something very similar.

Rickard

[Guest Nigel]

Rickard;

It is highly unlikeley that the problem is the tweeters, or related to the speakers in any manner because it is the same with all four speakers.

The AR6 has a cone tweeter, and is a two way design. The AR91 has a liquid cooled dome tweeter and dome midrange. Failure of these very different drivers will sound very different.

Are you absolutely positive that the sounds are not coming from the disc itself, and that because the AR speakers are so accurate, you are now only hearing it?

[Guest Sweden]

Nigel,

at this point I'm not sure on anything :-)

But I have tested the same CDs in other CD-players and the issue has not occured in any of them. Yes, they have been quite inferior to the AR-speakers and I have read that very good speakers can bring out this kinds of defects, but it occurs on to many of our CDs! I mean, not all of them could be so badly produced that they passed through the production with this problem.

I wish you were here to experience it.

Again, I have some more tests to do and I hope it's the CD-player/DVD.

Cheers

Rickard

[Guest dogmeninreno]

>Nigel,

>

>at this point I'm not sure on anything :-)

>

>But I have tested the same CDs in other CD-players and the

>issue has not occured in any of them. Yes, they have been

>quite inferior to the AR-speakers and I have read that very

>good speakers can bring out this kinds of defects, but it

>occurs on to many of our CDs! I mean, not all of them could be

>so badly produced that they passed through the production with

>this problem.

>

>I wish you were here to experience it.

>

>Again, I have some more tests to do and I hope it's the

>CD-player/DVD.

>

>Cheers

>Rickard

It seems that if it appeared on your TV as you indicated, It is not your speakers in my opinion. I would suspect connections and or powerline interference as I have indicated. Try a GOOD power line conditioner like this one on eBay before going further. It may amaze you how a bad sine wave will interfere in some harmonics.

[Guest dogmeninreno]

Rikard, Here is the link to the Adcom. Dale http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...3094449993&rd=1

[Guest Sweden]

Hi Dale,

I can agree with your arguing since the issue is the same in ALL speakers, incl the TV. So it seems that the current or an equipment connected to it all (or both) could be it.

I performed a small test yesterday, unplugging the amp and the DVD from the usual plug and moved them to another. I then played the bad songs over and over for 30-40 minutes and it was NO distorsion or sound-issue at all! I had to leave for a soccer-game and when I came back I wanted to show my wife the positive findings. All cables were exactly the same as I left them. Unfortunately, the sound-issue was now there..... But the fact that the bad songs worked just fine, must point to something outside my stereo and TV-equipment after all.

I will look here in Sweden for a line-enhancer. I think that it could be it. I will also take a pair of speakers to the local hifi-dealer and test them there. I need a new receiver anyway since I have problem with the old one.

Cheers

Rickard

[Guest Sweden]

Hi all,

I went to my friend and tested my AR6 at his home and NO SOUNDISSUE!!!

Tomorrow I will borrow his CD-player and play at my home. If the soundissue is still there, then I guess that it is the current.

TO BE CONTINUED

[rrcrain]

Perhaps a mildly corroded or dirty switch on your preamp is responsible for the noise? Have you tried wiggling switches to see if one has an impact on the noise?

[Guest Sweden]

>Perhaps a mildly corroded or dirty switch on your preamp is

>responsible for the noise? Have you tried wiggling switches to

>see if one has an impact on the noise?

Hi, I have tried that. I had upon that moment tried everything except:

- testing speakers at other location

- testing speakers with other CD/DVD than my own.

Amongst other testing with a brand new Arcam avr200 that created the exact same crunching sound.

The above two tests was the only ones left before facing the fact that it was the speaker, since it worked, I can conclude that it isn't the speakers. Next test is to borrow a NAD CD-player and test it in my home. Noice -> then there are some "noice" in the current that creates this.

Cheers

[Guest Sweden]

OK, so now I finally have the conclusion!

I borrowed a NAD CD player and when trying to hook it in, I had to remove a cable that I had from the TV to the DVD-cables and guess what.....?

The sound is perfect on both the TV and from the speakers. Previously I tried to disconnect the antenna-cable, but apparently that wasn't enough.

So the previous coupling with the DVD connected to the TV and the amp seems to have created some kind of problem that in turn created this chrunching soundissue.

To be sure I have played on my own DVD and the sound is superb also there.

Thanks for all your suggestions. Now I will just listen and enjoy!

Rickard

[Guest dogmeninreno]

Please get a GOOD AC line conditioner. I have years of experience overseas with power plants and distribution problems. I have a Adcom 515 that I will send you (if you pay the freight and $125.00 for the unit, but you have not responded as to what your utility is supplying to you. Dale

[Guest dogmeninreno]

Rikard, Well, I should have searched the threads. 220V 60 Hz is a problem for some line conditioners. The Adcom I proposed will not work but i will look further. Dale

[Guest dogmeninreno]

I ment 50 Hz, Dale

[Guest Sweden]

Hi Dale, thanks for your concern!

Eventhough my problems seems to be solved I guess that a line enhancer would be of interest. Unfortunately, you guys in U.S.A. have a different kind of specs regarding the current, TV etc. so an american line enhancer is not possible to use (plug, voltage). I have checked the equivalent here in Sweden and the cost is huge for such equipment. From 300$ for the most basic model to around 2000$ for a more "professional one".

Now when I (finally) have solved it, I'm back at square one and can concentrate on what I was doing before all this fuss, i.e. buy a new amp. The current amp works fine except for when playing at low volumes. this is a known "feature" in the Luxmans of the 90s that didn't had a digital volume control.

BTW, when I had my AR6 with me to my friend and tested them, he was truly amazed with the sound. He had a pair of Dali's from -98 (fronts) and he thinked the sound was extremly good. I'll guess he'll be stunned when he hear my AR91s. :-)

Rickard