Capacitor life

[Racerxnet]

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

 

 

[Speedskater]

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

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

[StephenJK]

48 minutes 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

 

 

In my experience with industrial power supplies we started to see early failure of electrolytic capacitors after close to 20 years, exponentially so after that.  It seems like 25 years is the outside for a good quality electrolytic capacitor.  

 

With power supplies, you start to get a bit of noise and then slightly unstable output and then an unusable supply.  I suspect with capacitors in speakers a failure would not be so obvious, but would result in the right frequency not getting to the right driver.

[Ralf11]

there is a wiki on capacitor rot - you'll need a manf. date for your gear

[Racerxnet]

What do you guys think a good replacement would be? 

 

MAK

[Ralf11]

Infi-Caps have street cred

[Racerxnet]

1 minute ago, Ralf11 said:

there is a wiki on capacitor rot - you'll need a manf. date for your gear

The last date of manufacture was 1996 for this line of Genesis speakers.

 

MAK

[RickyV]

1 hour 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

 

 

Are you sure it is the speakers capacitors that are failing and not the driver itself. usually the drivers cone surround are first to go. They dry out and become harder and less flexible. This of course influences the parameters of the driver. You can carefully touch the surround with your fingertip. You can do the same with the tweeter, if dome tweeter, extra careful and only a tiny bit. See if still flexible.

Of cause 24 year is old for speakers and even capacitors age so it is possible. The sound of a speaker is for a good deal determined by its capacitors so do not buy industrial caps they will sound industrial. 
Capacitors brands: Audyn Cap Plus is good, Jantzen Capacitors, Mundorf Capacitors, ClarityCap Capacitors, and many more. Just replaced them with the correct values.

[Richard Dale]

33 minutes ago, SJK said:

In my experience with industrial power supplies we started to see early failure of electrolytic capacitors after close to 20 years, exponentially so after that.  It seems like 25 years is the outside for a good quality electrolytic capacitor.  

 

With power supplies, you start to get a bit of noise and then slightly unstable output and then an unusable supply.  I suspect with capacitors in speakers a failure would not be so obvious, but would result in the right frequency not getting to the right driver.

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.

[Racerxnet]

23 minutes ago, RickyV said:

Are you sure it is the speakers capacitors that are failing and not the driver itself. usually the drivers cone surround are first to go. They dry out and become harder and less flexible. This of course influences the parameters of the driver. You can carefully touch the surround with your fingertip. You can do the same with the tweeter, if dome tweeter, extra careful and only a tiny bit. See if still flexible.

Of cause 24 year is old for speakers and even capacitors age so it is possible. The sound of a speaker is for a good deal determined by its capacitors so do not buy industrial caps they will sound industrial. 
Capacitors brands: Audyn Cap Plus is good, Jantzen Capacitors, Mundorf Capacitors, ClarityCap Capacitors, and many more. Just replaced them with the correct values.

 

The Mid panel is either the 48" carver or BG48 ribbon. There is no surround on this. The tweeters do not have surrounds on them either. This is a 4 column system with separate bass and Mid/Hi panels. Bass columns are servo driven. I am considering Mundorf Supreme's.

 

 

 

[Speedskater]

1 minute ago, 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.

I think that they are film rather than electrolytic capacitors.

But they are hand made. That alone makes them suspect.

[Racerxnet]

3 minutes ago, 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.

 

 

Richard,

 

PPT are film caps.

[Richard Dale]

Just now, Speedskater said:

I think that they are film rather than electrolytic capacitors.

But they are hand made. That alone makes them suspect.

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

[RickyV]

Ah, what is model?

 

[gmgraves]

13 minutes ago, Racerxnet said:

The last date of manufacture was 1996 for this line of Genesis speakers.

 

MAK

Mostly, capacitor life is tied to electrolytics. Crossover and other small signal, non-polarized capacitors live much longer. I recently refurbished a Stromberg-Carlson console radio that’s over 70 years old (1948), and while the electrolytics in the power supply were long past even being capacitors, the paper and foil small signal capacitors (mostly between 0.22 and 0.47 mFd. types with one 0.68) which were bee’s wax dipped, were still good and worked perfectly. Of course, I can’t vouch that they were still their original, marked values, but they were close enough not to affect the radio’s AM, FM, Short Wave or audio performance! This console was quite interesting. The woofer was horn loaded into an acoustic labyrinth type folded horn, and had a two inch speaker as a tweeter! When I finished retubing it, and fixing the power supply, it sounded excellent (for a “brown goods” console radio. I bet it was very expensive when new).

It had a 10 -12 Watt amp using push-pull 6V6 output tubes and the radio had 4 FM IF stages and 6 AM/short wave IFs!

[RickyV]

5 minutes ago, Racerxnet said:

 

The Mid panel is either the 48" carver or BG48 ribbon. There is no surround on this. The tweeters do not have surrounds on them either. This is a 4 column system with separate bass and Mid/Hi panels. Bass columns are servo driven. I am considering Mundorf Supreme's.

 

 

 

This might be a good subjective source. 
http://www.humblehomemadehifi.com/Cap.html

 

[Racerxnet]

1 minute ago, gmgraves said:

Mostly, capacitor life is tied to electrolytics. Crossover and other small signal, non-polarized capacitors live much longer. I recently refurbished a Stromberg-Carlson console radio that’s over 70 years old (1948), and while the electrolytics in the power supply were long past even being capacitors, the paper and foil small signal capacitors (mostly between 0.22 and 0.47 mFd. types with one 0.68) which were bee’s wax dipped, were still good and worked perfectly. Of course, I can’t vouch that they were still their original, marked values, but they were close enough not to affect the radio’s AM, FM, Short Wave or audio performance! This console was quite interesting. The woofer was horn loaded into an acoustic labyrinth type folded horn, and had a two inch speaker as a tweeter! When I finished retubing it, and fixing the power supply, it sounded excellent (for a “brown goods” console radio. I bet it was very expensive when new).

It had a 10 -12 Watt amp using push-pull 6V6 output tubes and the radio had 4 FM IF stages and 6 AM/short wave IFs!

 

Well I know you are beyond my knowledge with this stuff. I can solder and paint by numbers though!

[gmgraves]

5 minutes ago, Racerxnet said:

 

The Mid panel is either the 48" carver or BG48 ribbon. There is no surround on this. The tweeters do not have surrounds on them either. This is a 4 column system with separate bass and Mid/Hi panels. Bass columns are servo driven. I am considering Mundorf Supreme's.

 

 

 

Most of those caps are Mylar. They are probably fine. I’d change that purple one, though. It IS an electrolytic of most likely Japanese manufacture, and I’d replace it with a Japanese Nichicon or equivalent of the same value.

[Richard Dale]

2 minutes ago, Racerxnet said:

 

Well I know you are beyond my knowledge with this stuff. I can solder and paint by numbers though!

Could it just as easily be the ribbons ageing? It is obviously an expensive speaker and just going in and attacking the crossovers without nailing down exactly what the problem is, seems the wrong way to go about it to me.

[Racerxnet]

3 minutes ago, RickyV said:

This might be a good subjective source. 
http://www.humblehomemadehifi.com/Cap.html

 

 

I just read another article on Caps and their characteristics for the crossovers. It was a good read.

 

MAK

[Racerxnet]

1 minute ago, Richard Dale said:

Could it just as easily be the ribbons ageing? It is obviously an expensive speaker and just going in and attacking the crossovers without nailing down exactly what the problem is, seems the wrong way to go about it to me.

 

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

[Richard Dale]

1 minute 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

I’m afraid I don’t actually have much of a clue, I only commented originally because I hadn’t heard about any cases of speaker crossovers failing like this. I think gmgraves suggestion of just replacing the Culver electrolytic sounds sensible and low risk. 

[RickyV]

In the picture I think I see a rotary switch and a potentiometer, correct? What those for? Any relevance to the high tones?

[Racerxnet]

1 minute ago, RickyV said:

In the picture I think I see a rotary switch and a potentiometer, correct? What those for? Any relevance to the high tones?

3 position rotary switch for the midrange; Low, medium and high. Potentiometer for the 3 rear tweeters and it checks out good. 0.4 to 5.4 ohms. No dead spots or rough feeling.

 

 

[Speedskater]

39 minutes ago, Richard Dale said:

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

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.