Capacitor life

[Richard Dale]

6 minutes ago, Speedskater said:

I think that you are correct!

It was Handmade Electronics Co. that was selling them.

in which case Reliable brand capacitors should last a century.

There’s a doc here about them:

 

http://www.reliablecapacitors.com/pdf/capacitors catalog.pdf

 

it doesn’t actually mention expected lifetimes. Maybe I’m a bit gullible but I have to say I would expect things under a name like reliablecapacitors.com as fitted to mega expensive Genesis speakers to be reliable.

[Richard Dale]

43 minutes ago, Racerxnet said:

 

Richard,

There is only 1 ribbon for each side. 15 tweeters for each panel. The ribbon is for the Mid range only. I am trying to nail down the issue as you describe without replacing everything like a shade tree mechanic. What has been suggested is that if I have to de-solder the caps to test with a meter, I may as well replace them. What do you suggest if you hear a rolled off top end??

 

MAK

Are both channels the same? If so then I would have thought that indicates something might be ageing rather than actually failing. It seems unlikely that both channels would fail in the same way at the same time, and have the effect of rolling off the treble in the same way.

[Ralf11]

Maybe just sell the speakers or give them to Goodwill, then buy some new ones?

[4est]

3 hours ago, Speedskater said:

I think that those are hand made capacitors, so life span is questionable.

Replace them with capacitors made by a major industrial capacitor manufacture.

Surely you jest?

[4est]

4 hours ago, Racerxnet said:

Whats the life span of capacitors in our equipment. I am asking because it seems that the top end is rolled off on my speakers and they are pushing 24 years old. The caps are REL-CAPS PPT series. What to replace them with?? Suggestions!

 

MAK

 

 

If your speakers are losing highs, it is not likely these. PM Superdad here, and he can give you the low down. These are a film and foil (polypropylene and tin?) capacitor, and they do not age like an electrolytic one. These are also not bad or hand made parts. You would have found these in ARC equipment IIRC. Sure there are better parts available, but they will cost you. It is possibly the problem, but unlikely IMO. To my knowledge these are still made under the AudioCap name.

[Ralf11]

ARC uses Infini-Caps

[4est]

1 minute ago, Ralf11 said:

ARC uses Infini-Caps

They used to these IIRC. I don's own any modern ARC gear.

[Richard Dale]

8 minutes ago, Ralf11 said:

ARC uses Infini-Caps

They may well do today, but as at 1989 or when the SP9 mkII was being sold (I bought one then and still have it, so I have some personal interest in the lifetime of its caps), it had rel caps. Here is a picture of one:

 

[4est]

2 minutes ago, Richard Dale said:

They may well do today, but as at 1989 or when the SP9 mkII was being sold (I bought one then and still have it, so I have some personal interest in the lifetime of its caps), it had rel caps. Here is a picture of one:

 

I bet they still work too!

[Ralf11]

12 minutes ago, Richard Dale said:

They may well do today, but as at 1989 or when the SP9 mkII was being sold (I bought one then and still have it, so I have some personal interest in the lifetime of its caps), it had rel caps. Here is a picture of one:

 

 

pic is broke but my ARC pre-amp is an LS25 Mk II

 

https://www.arcdb.ws/LS25/LS25.html

 

So, sometime between 1989 to 2000 or so was the change-over.

[Richard Dale]

7 minutes ago, 4est said:

I bet they still work too!

Yes, as a side effect of this discussion I’ve learnt than my SP9 may well be still be going strong. I haven’t actually used it for about 10 years. I had been thinking of having a clear out and selling some stuff including the SP9, but assumed the SP9 used electrolytic caps which surely will be dead after thirty years, and was concerned it probably would be dead. But maybe not..

[fas42]

3 hours ago, Racerxnet said:

 

 

What I see here is dodgy looking switching/adjusting hardware ... what I would immediately do is bypass that hardware with decent quality fixed value parts.or wire - and see what that told me ...

[Ralf11]

I'd keep the SP 9 for the switches and knobs alone...

[Richard Dale]

3 minutes ago, Ralf11 said:

I'd keep the SP 9 for the switches and knobs alone...

Yes the SP9 has a strong family resemblance to the LS25, with the chunky switches and knobs. Some of the later ARC pre-amps look a bit cheap and nasty by comparison IMHO, such as this SP16:

 

[Racerxnet]

1 hour ago, 4est said:

If your speakers are losing highs, it is not likely these. PM Superdad here, and he can give you the low down. These are a film and foil (polypropylene and tin?) capacitor, and they do not age like an electrolytic one. These are also not bad or hand made parts. You would have found these in ARC equipment IIRC. Sure there are better parts available, but they will cost you. It is possibly the problem, but unlikely IMO. To my knowledge these are still made under the AudioCap name.

 

There is a Vishay resistor I'll test and see if it still specs out. 

 

MAK

[Speedskater]

2 hours ago, 4est said:

Surely you jest?

About what?

Turns out that I was incorrect about them being handmade.

They are made by a major industrial capacitor manufacture Reliable. The should last a century.

[Archimago]

1 hour ago, Racerxnet said:

 

There is a Vishay resistor I'll test and see if it still specs out. 

 

MAK

 

Hmmm, @Racerxnet, I'm thinking first things first before replacing stuff... Have you done some measurements on those speakers' frequency responses and maybe compared the the pair to see whether one is worse than the other?

 

This will obviously also give you a baseline to compare if you did proceed to replace caps... Last thing you'd want to do is go in blind and perhaps make things worse!

 

 

[Ralf11]

also, pop the grill off and look at foam surrounds on the cones - use a bright flashlight beam

[fas42]

3 hours ago, Richard Dale said:

Yes the SP9 has a strong family resemblance to the LS25, with the chunky switches and knobs. Some of the later ARC pre-amps look a bit cheap and nasty by comparison IMHO, such as this SP16:

 

 

Chunkiness may be satisfying visually, and to the touch - but it doesn't guarantee adequate electrical integrity for optimum SQ. Personally, I would favour the the more recent preamp as possibly having a  better technical solution for controlling its functions.

[4est]

9 hours ago, Speedskater said:

About what?

Turns out that I was incorrect about them being handmade.

They are made by a major industrial capacitor manufacture Reliable. The should last a century.

You weren't just a little wrong, but completely off base. If you don't actually know, perhaps you should not guess or speculate- that's spreading FUD. A film and foil cap used in a speaker should last the life of the speaker. Of course it is possible that there is a defective one, but it seem really unlikely both would fail the same.

[Racerxnet]

10 hours ago, Archimago said:

 

Hmmm, @Racerxnet, I'm thinking first things first before replacing stuff... Have you done some measurements on those speakers' frequency responses and maybe compared the the pair to see whether one is worse than the other?

 

This will obviously also give you a baseline to compare if you did proceed to replace caps... Last thing you'd want to do is go in blind and perhaps make things worse!

 

 

Gary Koh wrote a reply some time ago regarding the bass columns accelerator causing a plus minus 18db response from 18 to 90hz. This may be the cause of the issue. I'll measure this soon. I have not done anything so far but investigate where the problem may be. Reliable Cap is going to send me the specs that Genesis requested for cap values. Thanks to everyone on this. 

 

Mark

[StephenJK]

On 1/7/2020 at 3:33 PM, Richard Dale said:

Are you sure that REL-CAPS PPT caps are electrolytic? It would seem strange to me be fit a high quality speaker with cross overs that might fail after only 20 years.

My mistake, I foolishly presumed they were electrolytic types, otherwise there wouldn't be an issue with aging, or shouldn't be.  I have seen electrolytic capacitors used in the Klipschorn speaker crossovers.  

 

 

[4est]

On 1/7/2020 at 3:39 PM, Richard Dale said:

Well I believe ‘REL’ in the name is short for reliable, and so I’m not particularly convinced by that argument.

Correct. Reliable is an OEM manufacturer. These are not some boutique parts.

 

[Racerxnet]

Can any of you guys identify the rotary selector switch used for the mid range setting. I am looking for a direct replacement before having to re-engineer the switch to the board. Upper left side of pic. The output to the midrange panel  is intermittent when wiggling it. 

 

 

[sandyk]

51 minutes ago, Racerxnet said:

Can any of you guys identify the rotary selector switch used for the mid range setting. I am looking for a direct replacement before having to re-engineer the switch to the board. Upper left side of pic. The output to the midrange panel  is intermittent when wiggling it. 

 

 

 

I presume that you have tried squirting some Isopropyl Alcohol into it ?