Dented caps in new Douk A5

[Schlippwhip68]

I bought this over 3 months ago and it’s been say more or less in the box unused since it arrived.
I pulled it out today and set it up. During set up the 63v Cap caught my attention. As you can see in the photo, quite a dent we have there.
This was bought on Ali Express. I am a little concerned but so far today no hits on the performance of the amp itself.
I can’t return it as the return window is now closed. There are mixed opinions on dented caps across the spectrum but personally speaking I would certainly not rather have one and to be honest am a little surprised that this was sent.

If I can track down a replacement cap then I may just do that.

 

[Roland68]

I bought this over 3 months ago and it’s been say more or less in the box unused since it arrived.
I pulled it out today and set it up. During set up the 63v Cap caught my attention. As you can see in the photo, quite a dent we have there.
This was bought on Ali Express. I am a little concerned but so far today no hits on the performance of the amp itself.
I can’t return it as the return window is now closed. There are mixed opinions on dented caps across the spectrum but personally speaking I would certainly not rather have one and to be honest am a little surprised that this was sent.

If I can track down a replacement cap then I may just do that.
View attachment 501919

Such dents don't matter much as long as the capacitor remains sealed.
It's strange that I can't find the Rubycon JXF in 3300uF/63V in my datasheets, and I'm not familiar with it. At 63 volts, the maximum capacitance is 1500uF, but that doesn't necessarily mean anything.
If you tell me the dimensions, I can recommend a replacement.

 

[Schlippwhip68]

Such dents don't matter much as long as the capacitor remains sealed.
It's strange that I can't find the Rubycon JXF in 3300uF/63V in my datasheets, and I'm not familiar with it. At 63 volts, the maximum capacitance is 1500uF, but that doesn't necessarily mean anything.
If you tell me the dimensions, I can recommend a replacement.

Thanks, DxL=18x40mm.
I have had a scout about but Mousers page is a bit hard to discern as to what they are actually selling. For example I looked for the Rubycon 63v 3300uf and found it but the Mouser page confuses it with 16v 3300uf pictorial and gives the data sheet specifically to the 6.3v…?

I will have to ring them in the morning to confirm either way.

 

[Roland68]

Thanks, DxL=18x40mm.
I have had a scout about but Mousers page is a bit hard to discern as to what they are actually selling. For example I looked for the Rubycon 63v 3300uf and found it but the Mouser page confuses it with 16v 3300uf pictorial and gives the data sheet specifically to the 6.3v…?

I will have to ring them in the morning to confirm either way.

There seem to be serious supply problems with these capacitors at the moment; Mouser and Digikey are almost completely out of stock.

You could try looking for a Rubycon 63ZLJ2700M18X40 somewhere. I would look for 63V capacitors with 2200 or 2700uF and better electrical specifications; that's more suitable for the TPA3255 in this case than high capacitance.

 

[respice finem]

The culprit is the transparent window

but seriously: this should not happen.

 

[Sokel]

Problem is size in there, Mouser carries this in stock:

Loading…

eu.mouser.com

If heat is concern though, these are 85° C rated, not 105° C.

These low ESR ones would fit as well:

Loading…

eu.mouser.com

Edit: in case you find snap-ins like the Vishay I posted you better measure hole diameter and spacing, these are 10mm ones.

 

[MCH]

JXF series does not even include any 18x40 let alone 63v 3300uF, but these exact ones have been spotted in Aiyima A70 mono amps as well. Lcsc doesn't carry them either.... But who knows, I had a similar case of a capacitor not available in catalog in the past, contacted the manufacturer (chemi-con in my case) and they explained that they do sell values beyond what is public listed.

 

[Timcognito]

@Douk Audio Please comment

 

[Schlippwhip68]

Found this and now it makes sense. From 6.3-400v.

 

[Sokel]

Found this and now it makes sense. From 6.3-400v.View attachment 501948

It's the ones I posted,yes.
General purpose, only 85° C rated at 2000 hours.

Nothing special but at least genuine.
The dented one of yours can't be sealed any more such an amount of dent would make it expand all around if sealed, at least at the top.
I'm really curious about its insides.

 

[Joe Smith]

You would think this would have been noted in QC review before leaving the production line, what with the transparent window and all…

 

[Onecat]

My first post here.

Don't trust a dented aluminum electrolytic.
k

 

[Schlippwhip68]

It's the ones I posted,yes.
General purpose, only 85° C rated at 2000 hours.

Nothing special but at least genuine.
The dented one of yours can't be sealed any more such an amount of dent would make it expand all around if sealed, at least at the top.
I'm really curious about its insides.

….so in this case, I’m speculating that without the seal and with the dent it’s still safe to use…?… it has been in operation for around 10 hours and with no issues but I do understand that’s possibly also no certification of a safe cap post dent.

 

[Onecat]

For a while, yes.
These have a rubber plug on the lead-end and the top of the case usually has pre-scribed lines ( + ), that if/when the cap's innards expand, either the rubber plug vents or the scribed lines split and release any pressure that develops when the cap overheats (or shorts out and tries to explode). These do not have a lot of 'space' inside to expand, so it is already a bit squashed, then it is already bearing pressure and possibly trying to vent. In some cases, the 'dent' can be sufficient to breach the insulative layers between the foil and paper layers. Nasty scenario.

A 63Vdc cap is just at the lower edge of hazardous voltage and likely exposed to enough energy to pose a risk of failure in worst case conditions. I say this not to scare you.. chances are it will last a good long time, but if you value this gadget, just take a stab at replacing the cap. Go for a 105'C cap if you can find one.
k

 

[Joe Smith]

Or return it…

 

[Roland68]

….so in this case, I’m speculating that without the seal and with the dent it’s still safe to use…?… it has been in operation for around 10 hours and with no issues but I do understand that’s possibly also no certification of a safe cap post dent.

From experience, I wouldn't worry too much, but keep an eye on it over time to see if the lid bulges. It could easily last for years.

I don't know what the sourcing options are in the UK; perhaps you can find something locally.

During my tests with TPA3255 amplifiers, I came across the following types:
Nichicon UBY1J222MHL (available at Digikey)
Rubicon 63ZLJ2700M18X40

The following are all 41.5-42mm long, but should fit. All are available at Digikey.
Chemi-Con EKZN630ELL222MM40S
Nichicon UHW1J222MHD
Rubycon 63ZLH2200MEFC18X40

 

[Schlippwhip68]

From experience, I wouldn't worry too much, but keep an eye on it over time to see if the lid bulges. It could easily last for years.

I don't know what the sourcing options are in the UK; perhaps you can find something locally.

During my tests with TPA3255 amplifiers, I came across the following types:
Nichicon UBY1J222MHL (available at Digikey)
Rubicon 63ZLJ2700M18X40

The following are all 41.5-42mm long, but should fit. All are available at Digikey.
Chemi-Con EKZN630ELL222MM40S
Nichicon UHW1J222MHD
Rubycon 63ZLH2200MEFC18X40

Thanks, I found some Nichicons on Ali Express. Ordered 5 of these.

I have a curiosity over the glue they use to fix the caps body to the board. Does anyone know what that glue is and maybe where to get it or can recommend an alternative?

 

[MCH]

Thanks, I found some Nichicons on Ali Express. Ordered 5 of these.

I have a curiosity over the glue they use to fix the caps body to the board. Does anyone know what that glue is and maybe where to get it or can recommend an alternative?View attachment 502099

My recommendation, if you want to buy from China, is lcsc.com AliExpress is a lottery with brand name passives. A lottery that you are likely to lose.

 

[Sokel]

Thanks, I found some Nichicons on Ali Express. Ordered 5 of these.

I have a curiosity over the glue they use to fix the caps body to the board. Does anyone know what that glue is and maybe where to get it or can recommend an alternative?View attachment 502099

That's the price of an original one piece, I seriously doubt that these are the real stuff.
It's your call though, so...

 

[Schlippwhip68]

That's the price of an original one piece, I seriously doubt that these are the real stuff.
It's your call though,

Looks legit. 5 star reviews from buyers. Here is a photo of a sent product.