Capacitor question

[Doobrey]

How do I tell if an electrolytic capacitor is polar or non polar by eye?

I want to replace some caps in a headphone amplifier and I know someone who can do the soldering for me but I’m struggling to identify what parts I need.

So far I’ve totalled up the amount of caps needed and their values.

 

[solderdude]

Bipolars are rare and usually have the letters BP or NP on them and/or lack polarisation symbols (+ or -).
Polar caps always have a + on them or a band with - symbols on it.

How old is the amp and why do you think all caps need to be replaced ?

Besides... if you can't really tell what polar electrolytics are and cannot recognize them I would not advise you to randomly replace them.

 

[DVDdoug]

Usually the negative side/terminal is marked with a minus sign. Or with surface mount caps there is sometimes a line across it showing the positive end. If you have a multimeter, you can confirm which end has positive voltage, relative to the other end (when installed on the powered-up board).

You will are not likely to find a non-polarized electrolytic in a headphone amp (or any amp). The only place I've seen a non-polarized electrolytic is in a speaker crossover.

I want to replace some caps in a headphone amplifier

What makes you think they are bad or "need improvement"? Contrary to common audiophile mythology, most capacitors in audio equipment aren't "critical". And most electrolytic capacitors are used in the power supply (or for "additional" power supply filtering) so they don't affect the sound unless they go completely bad.

 

[Doobrey]

It’s only 6 years old so not grey yet but I just wanted to take out the teapos and put in something higher quality for longevity and piece of mind.

Because of close inspect and your comments I’ve been able to figure out most of them are polar and (gold/black) and 4 (plain black) are non polar. There’s a clear + indication on the PCB.

 

[amirm]

Very strange to see any non-polarized caps in such a device. But the black pair does miss the polarity signs.

 

[restorer-john]

Non Polar (NP)

A non-polar capacitor has another giveaway. It is generally bigger in volume for the same value as compared to a polar electro. This is due to ot essentially being two polar capacitors connected back to back inside the can (an extra layer winding).

 

[Doobrey]

Very strange to see any non-polarized caps in such a device. But the black pair does miss the polarity signs.

Arcam rHead

 

[restorer-john]

Teapo brand (I see in that pic) are absolute bottom of the barrel capacitors.

 

[Doobrey]

there's only 4 NP caps

ones at the rear by the XLR RCA inputs are 100uf 16v

its the 2 at the front that are specced at 10uf 63v that I can't find any replacements for

 

[Doobrey]

Teapo brand (I see in that pic) are absolute bottom of the barrel capacitors.

Oh absolutely a cost cutting measure for sure that's why I want them gone. Every one is a teapo.

 

[Doobrey]

Full board pic NP highlighted

 

[Doodski]

Teapo brand (I see in that pic) are absolute bottom of the barrel capacitors.

How much money is saved by using cheapO caps instead of proper caps? When I was servicing gear we had a ton of service agreements with major brands and so if I needed parts I whipped out the service manual and ordered proper parts and if out of warranty I had a parts department to handle all this stuff for me so I could focus on repairs. So I'm not really up to speed on parts costs for various qualities of caps. Is it a substantial cost difference or is this penny pinching?

 

[Doobrey]

Would a 10uf 100vdc be a safe replacement for the 10uf 63vdc?

 

[gamerpaddy]

you might consider replacing them with foil caps if you find the right capacitance. wima is usually a good choice of brand
for example: a wima MKS2B051001N00JO00 would fit perfectly if you can find it in your country / available sellers.

you can use higher voltage ratings, but never lower.
you could also use higher capacitance in this case, but id rather stick to the value its using right now.

10uf is a lot for a foil type cap of this size, which makes them very expensive. but every major electrolytic cap manufacturer has a bipolar model in their lineup thats most likely better than the ones used..


teapo is jamicon, not absolute bottom of the barrel but they were really penny pinching in this unit.


i count 18 normal electrolytics and 4 bipolar capacitors, even with the top of the line, low esr, panasonic or nichicon types, we are talking 3..5 bucks in total for those parts
with jamicon, crapXon or whatever is on the cheapo-market, its probably 1 to 2 bucks.
in a 450 dollar device.... theres just no reason.

 

[Philbo King]

Would a 10uf 100vdc be a safe replacement for the 10uf 63vdc?

Yes

 

[JSmith]

The only place I've seen a non-polarized electrolytic is in a speaker crossover.

Unique to Arcam then?

Arcam DiVA Ampliers P75 Plus - Manual (Page 36)

Read online or download PDF • Page 36 / 42 • Arcam DiVA Ampliers P75 Plus User Manual • Arcam Car amplifier

www.manualsdir.com

P75 Plus Amplifier PCB
2V710 1 ELST NON POLAR 100UF 16V C147

Arcam DiVA CD72 Service Manual (Page 40 of 49) | ManualsLib

www.manualslib.com

Arcam FMJ AV8 Service Manual (Page 86 of 147) | ManualsLib

www.manualslib.com

I want to replace some caps in a headphone amplifier and I know someone who can do the soldering for me but I’m struggling to identify what parts I need.

If needed you can use polarised caps back to back (negative joined, in series with opposing polarities) to make a non polarised cap, so the joined cap will be the voltage rating of the 2 caps added (i.e. half the capacitance), but may have a little more distortion. Best to just get the NP's though.


JSmith

 

[Doobrey]

Thanks for the help, ive decided to go with Panasonic FM caps and have the whole lot re done.

Panasonics appear to fit perfectly in the Teapos places where as others like Elna Silmic would be far too big.

 

[Doodski]

ive decided to go with Panasonic FM caps

These bad boys?

https://industrial.panasonic.com/cdbs/www-data/pdf/RDF0000/ABA0000C1018.pdf

 

[Doobrey]

These bad boys?

https://industrial.panasonic.com/cdbs/www-data/pdf/RDF0000/ABA0000C1018.pdf

That’s the one

 

[Doodski]

That’s the one

I think the specs for the temp delta stuff are a bit outlandish and difficult to understand. But I think if Panasonics then they should have some integrity. I have had excellent results from both selling and servicing Panasonic gear. I like Panasonic!