[[email protected]]

I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Gary V

[JackA]

On Thursday, May 14, 2015 at 6:08:31 PM UTC-4, wrote:
I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Gary V

Getting adhesive to adhere to plastic is sometimes tough. I'd recommend tearing off the plastic covering of the capacitor, assuming there is one, and use most any type of epoxy, RTV, etc.

[Chuck[_12_]]

On Thu, 14 May 2015 15:08:28 -0700 (PDT), wrote:

I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Gary V


I would recommend Panasonic or Nichicon. Mouser or Digikey should
have them. I would put in a slightly higher voltage capacitor.

---
This email has been checked for viruses by Avast antivirus software.
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[Scott Dorsey]

wrote:
I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

Just cut the glue off with dykes and a knife. Desolder, solder in new
caps, go. Be careful desoldering, but the Soldapulit will be fine on
something like this. It's an easy board to work on.

I would also suggest, though, that if one cap has gone bad, the other
similar caps are on their way toward going bad and maybe should be
replaced at the same time.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Go to digi-key. Select Panasonic caps, select "in stock", select the correct
voltage and capacitance. Once you get to that point, select correct pin
spacing and ONLY buy 105C-rated caps. FC series is fine, HFC series is fine,
any of the 105C-rated ones will be fine.

There are lots of other good caps out there, but Panasonics from Digikey are
going to be both good and assuredly not counterfeit.

Use a little electronics-grade RTV to secure the new caps in. Digikey will
stock that also.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[JackA]

On Thursday, May 14, 2015 at 6:08:31 PM UTC-4, wrote:
I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Gary V

P.s. If 50V capacitors failed, go higher voltage, maybe 100V. It's amazing to me to see how capacitors grow smaller and smaller (from the '70's), mainly due to improvements dielectrics of insulation. But, they do fail....


We had some sodium vapor lamps, generally, the bulbs would fail. However, replacing the bulb no longer helped. I found on the internet, it's generally the capacitor that fails. Luckily, we had enough old capacitors that I could parallel and replace the old capacitor, but now with 600VAC capacitors rather than 300V! Hasn't failed yet!

Yapping:
But while were on the topic of dielectrics failing, some insulation can be reduced in thickness, but you face the risk of a pinhole in insulation. That is why it's best, if size isn't an issue, not to stress insulation, but use it for its physical thickness and never design it greater than 40V/mil, because, even if a pinhole, it won't fail. Actually, you design at 40V/mil, because at 50V/mil air begins to ionize!

BTW RTV = Room Temperature Vulcanizing (silicone rubber), General Electric Registered name. But, I'd still remove the shrink wrap plastic/vinyl cover and adhere to metal.

Jack

[JackA]

On Thursday, May 14, 2015 at 7:03:26 PM UTC-4, Scott Dorsey wrote:
wrote:
I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

Just cut the glue off with dykes and a knife. Desolder, solder in new
caps, go. Be careful desoldering, but the Soldapulit will be fine on
something like this. It's an easy board to work on.

I would also suggest, though, that if one cap has gone bad, the other
similar caps are on their way toward going bad and maybe should be
replaced at the same time.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Go to digi-key. Select Panasonic caps, select "in stock", select the correct
voltage and capacitance. Once you get to that point, select correct pin
spacing and ONLY buy 105C-rated caps. FC series is fine, HFC series is fine,
any of the 105C-rated ones will be fine.

There are lots of other good caps out there, but Panasonics from Digikey are
going to be both good and assuredly not counterfeit.

Use a little electronics-grade RTV to secure the new caps in. Digikey will
stock that also.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Been away from electronics (capacitor physical sizes), but don't they offer metal clamps (mounting) for larger capacitors? Why wait for adhesive to cure?

Where I shop, can't stand some of the other places mentioned here.
http://www.allelectronics.com/

Jack

[[email protected]]

On Thursday, May 14, 2015 at 4:03:26 PM UTC-7, Scott Dorsey wrote:
wrote:
I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

Just cut the glue off with dykes and a knife. Desolder, solder in new
caps, go. Be careful desoldering, but the Soldapulit will be fine on
something like this. It's an easy board to work on.

I would also suggest, though, that if one cap has gone bad, the other
similar caps are on their way toward going bad and maybe should be
replaced at the same time.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Go to digi-key. Select Panasonic caps, select "in stock", select the correct
voltage and capacitance. Once you get to that point, select correct pin
spacing and ONLY buy 105C-rated caps. FC series is fine, HFC series is fine,
any of the 105C-rated ones will be fine.

There are lots of other good caps out there, but Panasonics from Digikey are
going to be both good and assuredly not counterfeit.

Use a little electronics-grade RTV to secure the new caps in. Digikey will
stock that also.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

I do plan to do both sides, all four caps. But I'm still wondering what the
cement was used between the circuit board and capacitor. Should I also
use your suggested electronics-grade RTV for this? Some serious
vibrations in there. Thanks for the excellent advice.

Gary V

[Scott Dorsey]

wrote:
I do plan to do both sides, all four caps. But I'm still wondering what the
cement was used between the circuit board and capacitor. Should I also
use your suggested electronics-grade RTV for this? Some serious
vibrations in there. Thanks for the excellent advice.

I don't know what was used, but the three things you see used are hot glue,
RTV, and contact cement. Hot glue is good on a production line when you
are trying to get stuff out quickly. RTV is more stable in the long run
but takes longer to set. Contact cement is in-between.

Note that what you think is cement holding the cap in place might actually
be leaked-out dielectric. You'll know the truth either way when you get
the thing off the board.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[JackA]

On Thursday, May 14, 2015 at 6:45:48 PM UTC-4, Chuck wrote:
On Thu, 14 May 2015 15:08:28 -0700 (PDT), wrote:

I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Gary V


I would recommend Panasonic or Nichicon. Mouser or Digikey should
have them. I would put in a slightly higher voltage capacitor.

Chuck and I think logically correct!!! :-)

Jack

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

[JackA]

On Thursday, May 14, 2015 at 8:54:35 PM UTC-4, Scott Dorsey wrote:
wrote:
I do plan to do both sides, all four caps. But I'm still wondering what the
cement was used between the circuit board and capacitor. Should I also
use your suggested electronics-grade RTV for this? Some serious
vibrations in there. Thanks for the excellent advice.

I don't know what was used, but the three things you see used are hot glue,
RTV, and contact cement. Hot glue is good on a production line when you
are trying to get stuff out quickly. RTV is more stable in the long run
but takes longer to set. Contact cement is in-between.

Contact cement is for arts and crafts, girly stuff, should apply to both surfaces, let it get tacky, then bond. RTV, as you well know, will, get this, cure under water!!!


Jack


Note that what you think is cement holding the cap in place might actually
be leaked-out dielectric. You'll know the truth either way when you get
the thing off the board.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected]]

On Thursday, May 14, 2015 at 4:03:26 PM UTC-7, Scott Dorsey wrote:
wrote:
I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

Just cut the glue off with dykes and a knife. Desolder, solder in new
caps, go. Be careful desoldering, but the Soldapulit will be fine on
something like this. It's an easy board to work on.

I would also suggest, though, that if one cap has gone bad, the other
similar caps are on their way toward going bad and maybe should be
replaced at the same time.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Go to digi-key. Select Panasonic caps, select "in stock", select the correct
voltage and capacitance. Once you get to that point, select correct pin
spacing and ONLY buy 105C-rated caps. FC series is fine, HFC series is fine,
any of the 105C-rated ones will be fine.

There are lots of other good caps out there, but Panasonics from Digikey are
going to be both good and assuredly not counterfeit.

Use a little electronics-grade RTV to secure the new caps in. Digikey will
stock that also.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Sadly, I'm striking out with Panasonic and Nichicon which meet the specification I need.
I've tried both Digikey and Mouser. I believe there might be a Panasonic match which
are not of the FC or HFC series but the lead spacing doesn't work (I need 10 mm). Also
there are possible matches for 85C but not 105C as you recommended.

Before I initially posted this message I was tempted to order these:

http://www.amazon.com/gp/product/B00...2WVI880 A5TIO

But there is mininal specification information on the Amazon website but it's the
closest I have yet been able to find.

Gary V

[JackA]

On Thursday, May 14, 2015 at 11:30:13 PM UTC-4, wrote:
On Thursday, May 14, 2015 at 4:03:26 PM UTC-7, Scott Dorsey wrote:
wrote:
I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

Just cut the glue off with dykes and a knife. Desolder, solder in new
caps, go. Be careful desoldering, but the Soldapulit will be fine on
something like this. It's an easy board to work on.

I would also suggest, though, that if one cap has gone bad, the other
similar caps are on their way toward going bad and maybe should be
replaced at the same time.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Go to digi-key. Select Panasonic caps, select "in stock", select the correct
voltage and capacitance. Once you get to that point, select correct pin
spacing and ONLY buy 105C-rated caps. FC series is fine, HFC series is fine,
any of the 105C-rated ones will be fine.

There are lots of other good caps out there, but Panasonics from Digikey are
going to be both good and assuredly not counterfeit.

Use a little electronics-grade RTV to secure the new caps in. Digikey will
stock that also.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Sadly, I'm striking out with Panasonic and Nichicon which meet the specification I need.
I've tried both Digikey and Mouser. I believe there might be a Panasonic match which
are not of the FC or HFC series but the lead spacing doesn't work (I need 10 mm). Also
there are possible matches for 85C but not 105C as you recommended.

Oh, I see, you think heat destroyed your capacitor!!! That is why it failed on start-up, it was just way too hot in there!! Nothing at all due to voltage failure. 105? Gee, I think 60-65C is more common. Oh, maybe Scott recommended that high temperature due to hot gluing!! Or, maybe he's still thinking in the vacuum tubes days.

Jack


Before I initially posted this message I was tempted to order these:

http://www.amazon.com/gp/product/B00...2WVI880 A5TIO

But there is mininal specification information on the Amazon website but it's the
closest I have yet been able to find.

Gary V

[Chuck[_12_]]

On Thu, 14 May 2015 20:30:08 -0700 (PDT), wrote:

On Thursday, May 14, 2015 at 4:03:26 PM UTC-7, Scott Dorsey wrote:
wrote:
I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

Just cut the glue off with dykes and a knife. Desolder, solder in new
caps, go. Be careful desoldering, but the Soldapulit will be fine on
something like this. It's an easy board to work on.

I would also suggest, though, that if one cap has gone bad, the other
similar caps are on their way toward going bad and maybe should be
replaced at the same time.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Go to digi-key. Select Panasonic caps, select "in stock", select the correct
voltage and capacitance. Once you get to that point, select correct pin
spacing and ONLY buy 105C-rated caps. FC series is fine, HFC series is fine,
any of the 105C-rated ones will be fine.

There are lots of other good caps out there, but Panasonics from Digikey are
going to be both good and assuredly not counterfeit.

Use a little electronics-grade RTV to secure the new caps in. Digikey will
stock that also.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Sadly, I'm striking out with Panasonic and Nichicon which meet the specification I need.
I've tried both Digikey and Mouser. I believe there might be a Panasonic match which
are not of the FC or HFC series but the lead spacing doesn't work (I need 10 mm). Also
there are possible matches for 85C but not 105C as you recommended.

Before I initially posted this message I was tempted to order these:

http://www.amazon.com/gp/product/B00...2WVI880 A5TIO

But there is mininal specification information on the Amazon website but it's the
closest I have yet been able to find.

Gary V


These should do the trick.
http://www.mouser.com/ProductDetail/...fUlWhG3l 4%3d

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

[Scott Dorsey]

wrote:

Sadly, I'm striking out with Panasonic and Nichicon which meet the specification I need.
I've tried both Digikey and Mouser. I believe there might be a Panasonic match which
are not of the FC or HFC series but the lead spacing doesn't work (I need 10 mm). Also
there are possible matches for 85C but not 105C as you recommended.

Sounds like you want digi-key part 493-12475-ND. Nichicon VY series, which
doesn't have the best high frequency performance but is entirely respectable
and almost certain better than the original.

If the original is a snap-type, the 493-8661-ND is a little bulkier and
will last longer if you believe the rating.

I got that with the following search:
http://www.digikey.com/product-searc...&pageSize=2 5

I would never buy capacitors from a supplier like Amazon, there being so many
counterfeits out there on the aftermarket.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected]]

On Friday, May 15, 2015 at 6:16:34 AM UTC-7, Chuck wrote:
On Thu, 14 May 2015 20:30:08 -0700 (PDT), wrote:

On Thursday, May 14, 2015 at 4:03:26 PM UTC-7, Scott Dorsey wrote:
wrote:
I have a pair of Tannoy System 800a self powered monitors with
a blown filter capacitor on one side. Powering up one day I heard
a pop and then saw smoke. Clearly one of the 6800 uF 50 V capacitor's
had failed on examination. I think I can replace these but because the
circuit is inside the speaker they used 2 different types of glue to
secure them from vibration. The glue at the base of the capacitor is an
off-white hard substance and the glue binding a pair together is a clear
ATV glue-like sealer.

Just cut the glue off with dykes and a knife. Desolder, solder in new
caps, go. Be careful desoldering, but the Soldapulit will be fine on
something like this. It's an easy board to work on.

I would also suggest, though, that if one cap has gone bad, the other
similar caps are on their way toward going bad and maybe should be
replaced at the same time.

I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Go to digi-key. Select Panasonic caps, select "in stock", select the correct
voltage and capacitance. Once you get to that point, select correct pin
spacing and ONLY buy 105C-rated caps. FC series is fine, HFC series is fine,
any of the 105C-rated ones will be fine.

There are lots of other good caps out there, but Panasonics from Digikey are
going to be both good and assuredly not counterfeit.

Use a little electronics-grade RTV to secure the new caps in. Digikey will
stock that also.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Sadly, I'm striking out with Panasonic and Nichicon which meet the specification I need.
I've tried both Digikey and Mouser. I believe there might be a Panasonic match which
are not of the FC or HFC series but the lead spacing doesn't work (I need 10 mm). Also
there are possible matches for 85C but not 105C as you recommended.

Before I initially posted this message I was tempted to order these:

http://www.amazon.com/gp/product/B00...2WVI880 A5TIO

But there is mininal specification information on the Amazon website but it's the
closest I have yet been able to find.

Gary V


These should do the trick.
http://www.mouser.com/ProductDetail/...fUlWhG3l 4%3d

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

Thank you for the effort Chuck. I think between you and Scott I have
what I need to do this repair.

Gary V

[Dave Plowman (News)]

In article ,
wrote:
I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Hot melt glue seems to be the favourite used these days in production.

--
*Would a fly without wings be called a walk?

Dave Plowman London SW
To e-mail, change noise into sound.

[[email protected]]

On Friday, May 15, 2015 at 6:57:11 AM UTC-7, Scott Dorsey wrote:
wrote:

Sadly, I'm striking out with Panasonic and Nichicon which meet the specification I need.
I've tried both Digikey and Mouser. I believe there might be a Panasonic match which
are not of the FC or HFC series but the lead spacing doesn't work (I need 10 mm). Also
there are possible matches for 85C but not 105C as you recommended.

Sounds like you want digi-key part 493-12475-ND. Nichicon VY series, which
doesn't have the best high frequency performance but is entirely respectable
and almost certain better than the original.

If the original is a snap-type, the 493-8661-ND is a little bulkier and
will last longer if you believe the rating.

I got that with the following search:
http://www.digikey.com/product-searc...&pageSize=2 5

I would never buy capacitors from a supplier like Amazon, there being so many
counterfeits out there on the aftermarket.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Yes, I was weary of Amazon too, which I why I decided to consult the experts. I
must say that I'm not really a fan of powered monitors simply because it seems
like a bad idea to put the electronics inside the speaker. I had to track down a
a loose component once which caused audible vibrations. My primary monitors
are passive for this reason.

Again, thank you very much.

Gary V

[JackA]

On Friday, May 15, 2015 at 10:32:23 AM UTC-4, Dave Plowman (News) wrote:
In article ,
wrote:
I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Hot melt glue seems to be the favourite used these days in production.

- I fear to ask, production of what!!?? :-)

Jack

--
*Would a fly without wings be called a walk?

Dave Plowman London SW
To e-mail, change noise into sound.

[John Williamson]

On 15/05/2015 18:46, JackA wrote:
On Friday, May 15, 2015 at 10:32:23 AM UTC-4, Dave Plowman (News) wrote:
In article ,
wrote:
I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Hot melt glue seems to be the favourite used these days in production.

- I fear to ask, production of what!!?? :-)

Anything up to and including aeroplanes.


--
Tciao for Now!

John.

[JackA]

On Friday, May 15, 2015 at 3:20:11 PM UTC-4, John Williamson wrote:
On 15/05/2015 18:46, JackA wrote:
On Friday, May 15, 2015 at 10:32:23 AM UTC-4, Dave Plowman (News) wrote:
In article ,
wrote:
I'm looking for help identifying what products I should use to secure the
new capacitors. Also if anyone has a suggestion for a particular brand of
capacitor I would appreciate it. Thanks.

Hot melt glue seems to be the favourite used these days in production.

- I fear to ask, production of what!!?? :-)

Anything up to and including aeroplanes.

I like that, Aeroplanes!! Not Airplanes (boring).
You must be from... Australia, New Zealand, South Africa, UK...

I guess it was their Loctite brand adhesive, especially made to bond most any type plastic. It was a two step process, Activate and Adhesive.
The activator came in a felt-tipped tube. This prepared the plastic to be bonded.
Anyway, I went to apply it and to make a long story short, I tore the metal activator open, since it was bone dry!!! Not a drop of moisture!
I contacted Henkel, they asked if I pressed the applicator hard enough. *sigh*
They were nice and sent me a replacement, but by that time, I used some epoxy for plastic!!

I've lost faith in Loctite...

http://www.henkelna.com/brands-solutions-6061.htm

Jack



--
Tciao for Now!

John.

[Trevor]

On 16/05/2015 12:29 AM, wrote:
I must say that I'm not really a fan of powered monitors simply because it seems
like a bad idea to put the electronics inside the speaker. I had to track down a
a loose component once which caused audible vibrations. My primary monitors
are passive for this reason.

It really shouldn't be that hard to isolate the electronics from
destructive vibration, and many manufacturers seem to manage it OK. The
big advantage of powered speakers of course is usually multiple
amplifiers matched to each driver, and the benefits of active
crossovers. But yes there are some disadvantages as well.

Trevor.

[Mat Nieuwenhoven]

On Thu, 14 May 2015 21:04:16 -0700 (PDT), JackA wrote:
snip
Oh, I see, you think heat destroyed your capacitor!!! That is why it failed on start-up,
it was just way too hot in there!! Nothing at all due to voltage failure. 105? Gee, I
think 60-65C is more common. Oh, maybe Scott recommended that high
temperature due to hot gluing!! Or, maybe he's still thinking in the vacuum tubes
days.

These electrolytic capacitors have a limited life. The ones with higher
specced temperature rating simply last much longer. I believe there are
less good in ESR (Equivalent Series Resistance) at higher frequencies,
but on the mains side of a power supply this is unimportant (but on the
secondary side of a switching power supply this ESR is very
important). Check out the Panasonic website for capacitors, they have
quite good specs usually, with graphs for endurance. Or for an
overview, check out wikipedia:
https://en.wikipedia.org/wiki/Electr...citor#Lifetime .

The Tannoy 800 has a 90W amp (for LF), and at elevated audio volume I
think the unit could become quite warm inside, so the choice for
high-temp capacitors could be well justified.

Mat Nieuwenhoven

[JackA]

On Sunday, May 17, 2015 at 3:20:51 PM UTC-4, Mat Nieuwenhoven wrote:
On Thu, 14 May 2015 21:04:16 -0700 (PDT), JackA wrote:
snip
Oh, I see, you think heat destroyed your capacitor!!! That is why it failed on start-up,
it was just way too hot in there!! Nothing at all due to voltage failure.. 105? Gee, I
think 60-65C is more common. Oh, maybe Scott recommended that high
temperature due to hot gluing!! Or, maybe he's still thinking in the vacuum tubes
days.

These electrolytic capacitors have a limited life. The ones with higher
specced temperature rating simply last much longer. I believe there are
less good in ESR (Equivalent Series Resistance) at higher frequencies,
but on the mains side of a power supply this is unimportant (but on the
secondary side of a switching power supply this ESR is very
important). Check out the Panasonic website for capacitors, they have
quite good specs usually, with graphs for endurance. Or for an
overview, check out wikipedia:
https://en.wikipedia.org/wiki/Electr...citor#Lifetime .

The Tannoy 800 has a 90W amp (for LF), and at elevated audio volume I
think the unit could become quite warm inside, so the choice for
high-temp capacitors could be well justified.

But, no one even suggested measuring voltage!!! Not that the person who couldn't determine the correct adhesive could, but still. I do not recall caps going bad, and I service lot of electronics. It gets, not warm, but HOT insides cars, and they now have plenty of electronics.

Thanks.

Jack


Mat Nieuwenhoven

[JackA]

On Sunday, May 17, 2015 at 3:20:51 PM UTC-4, Mat Nieuwenhoven wrote:
On Thu, 14 May 2015 21:04:16 -0700 (PDT), JackA wrote:
snip
Oh, I see, you think heat destroyed your capacitor!!! That is why it failed on start-up,
it was just way too hot in there!! Nothing at all due to voltage failure.. 105? Gee, I
think 60-65C is more common. Oh, maybe Scott recommended that high
temperature due to hot gluing!! Or, maybe he's still thinking in the vacuum tubes
days.

These electrolytic capacitors have a limited life. The ones with higher
specced temperature rating simply last much longer. I believe there are
less good in ESR (Equivalent Series Resistance) at higher frequencies,
but on the mains side of a power supply this is unimportant (but on the
secondary side of a switching power supply this ESR is very
important). Check out the Panasonic website for capacitors, they have
quite good specs usually, with graphs for endurance. Or for an
overview, check out wikipedia:
https://en.wikipedia.org/wiki/Electr...citor#Lifetime .

The Tannoy 800 has a 90W amp (for LF), and at elevated audio volume I
think the unit could become quite warm inside, so the choice for
high-temp capacitors could be well justified.

Just a FYI: In my old age, there's one thing I discovered. In cold weather, light switches and circuit breakers fail. May be due to metal contracting, and that the component is old and should be replaced. (4) FOUR instances, (2) light switches, (2) [panel] circuit breakers, in a very short time.

Jack

Mat Nieuwenhoven

[[email protected]]

Well I finally found the time to do this repair and I must say
it turned out quite well. I actually ordered both products suggested
by Chuck and Scott but ended up using the capacitors with the
best fit. The monitors sound great.

So if I can contribute something back to this thread, I found this
Silicone RTV product to cement the capacitors to the circuit board:

http://www.mouser.com/ProductDetail/...iOqB28aiw% 3d

As Scott suggested it is "Electronics Grade" and it worked great.

Thanks to everyone for helping me get this done.

Gary V

[hank alrich]

wrote:

Well I finally found the time to do this repair and I must say
it turned out quite well. I actually ordered both products suggested
by Chuck and Scott but ended up using the capacitors with the
best fit. The monitors sound great.

So if I can contribute something back to this thread, I found this
Silicone RTV product to cement the capacitors to the circuit board:

http://www.mouser.com/ProductDetail/...qs=%2fha2pyFad
ug5ugicRdJzQoVCrXoLzhQUKAiOqB28aiw%3d

As Scott suggested it is "Electronics Grade" and it worked great.

Thanks to everyone for helping me get this done.

Gary V

Congrats, Gary!

--
shut up and play your guitar * HankAlrich.Com
HankandShaidriMusic.Com
YouTube.Com/WalkinayMusic

[[email protected]]

On Thursday, June 11, 2015 at 2:30:39 PM UTC-7, hank alrich wrote:
wrote:

Well I finally found the time to do this repair and I must say
it turned out quite well. I actually ordered both products suggested
by Chuck and Scott but ended up using the capacitors with the
best fit. The monitors sound great.

So if I can contribute something back to this thread, I found this
Silicone RTV product to cement the capacitors to the circuit board:

http://www.mouser.com/ProductDetail/...qs=%2fha2pyFad
ug5ugicRdJzQoVCrXoLzhQUKAiOqB28aiw%3d

As Scott suggested it is "Electronics Grade" and it worked great.

Thanks to everyone for helping me get this done.

Gary V

Congrats, Gary!

--
shut up and play your guitar * HankAlrich.Com
HankandShaidriMusic.Com
YouTube.Com/WalkinayMusic

Thank you Hank. And I forgot to mention what a remarkable
resource this group is. I mean where else could you ask an audio
question and get great information in return. The usuals are
certainly Scott, Mike, Paul, Hank and plenty of others. Thank
you so much.

Gary V

[JackA]

On Thursday, June 11, 2015 at 9:09:10 PM UTC-4, wrote:
On Thursday, June 11, 2015 at 2:30:39 PM UTC-7, hank alrich wrote:
wrote:

Well I finally found the time to do this repair and I must say
it turned out quite well. I actually ordered both products suggested
by Chuck and Scott but ended up using the capacitors with the
best fit. The monitors sound great.

So if I can contribute something back to this thread, I found this
Silicone RTV product to cement the capacitors to the circuit board:

http://www.mouser.com/ProductDetail/...qs=%2fha2pyFad
ug5ugicRdJzQoVCrXoLzhQUKAiOqB28aiw%3d

As Scott suggested it is "Electronics Grade" and it worked great.

Thanks to everyone for helping me get this done.

Gary V

Congrats, Gary!

--
shut up and play your guitar * HankAlrich.Com
HankandShaidriMusic.Com
YouTube.Com/WalkinayMusic

Thank you Hank. And I forgot to mention what a remarkable
resource this group is. I mean where else could you ask an audio
question and get great information in return.

Audio?, you asked about glue. A few....

http://www.electronicspoint.com/
http://www.eevblog.com/forum/
http://forum.allaboutcircuits.com/fo...ronics-chat.5/

Jack :-)


The usuals are
certainly Scott, Mike, Paul, Hank and plenty of others. Thank
you so much.

Gary V