Are yellow Nippon Chemi-Con caps low leakage?

[Skywatcher]

I'm a big fan of Mr. Carlson and do find the outside foil lead on the tube equipment I work. I needed a good reason to build something like his foil test circuit and this is a better reason to do it.
Film cap polarity in the SS is like asking which way to reload the toilet paper dispenser. There's always a right way. If anything else it's a feeling of going the extra distance on the work.
Youtube'er "xraytonyb" has a foil finder device that is way more DIY than Mr. C's. The scope is fine but for reading the bigger film values, you need more than just a scope.

I watch both. Tony can be a "hoot" sometimes.

 

[mstewart]

I watch both. Tony can be a "hoot" sometimes.

I realize this wasn't really directed at me but I recently started watching xraytonyb myself. Sometimes he will say one single sentence that is like an aha! moment for me. It might be in the middle of an hour long talk and out of nowhere something clicks. I could ask questions on this forum until I just annoy everyone to death. So I'm trying to expand my knowledge. I recently bought the textbook Electronic Principals. Figured I read that as if I was school and then do the assignments in the book. If anyone could point me at some good learning resources I'd be very interested. Having an incomplete understanding of anything drives me a little nuts.

 

[mstewart]

You gotta watch it, there are Bi-Polar (also known as non-polar) caps in a LOT of gear in specific places.

How would I identify them? Of the 5 receivers I've recapped every electrolytic cap has has a black line indicating the negative side unless I am mistaken.

Edit: Or some other colored line down one side

 

[PTL-Pioneer]

How would I identify them? Of the 5 receivers I've recapped every electrolytic cap has has a black line indicating the negative side unless I am mistaken.

Edit: Or some other colored line down one side

I saw some bipolars that had BP written on them and were absent a line marking negative. But other than that not sure if there is another way they are identified visually

 

[mstewart]

I saw some bipolars that had BP written on them and were absent a line marking negative. But other than that not sure if there is another way they are identified visually

I was looking at Nichicon ES caps at the recommendation of leestereo. I noticed those have bp printed on them. But I can't recall ever seeing them in the 70's Pioneers I've worked on. Did Pioneer use them back then? Or was @Skywatcher's comment just to make me aware that they are in some other audio equipment?

 

[mstewart]

Here's a random unrelated question. I want to say that I read somewhere on this site that changing transistors on a tuner board is more likely to cause alignment issues than changing electrolytic capacitors. Is that true? I just changed all electrolytic caps on this 636 tuner. Haven't touched any transistors for this reason.

 

[EastPoint]

Here's a random unrelated question. I want to say that I read somewhere on this site that changing transistors on a tuner board is more likely to cause alignment issues than changing electrolytic capacitors. Is that true? I just changed all electrolytic caps on this 636 tuner. Haven't touched any transistors for this reason.

That is correct.

 

[Skywatcher]

How would I identify them? Of the 5 receivers I've recapped every electrolytic cap has has a black line indicating the negative side unless I am mistaken.

Edit: Or some other colored line down one side

Usually they have a PB or NP on them. But watch, there are SOME polarized that have the stripe for the POSITIVE, but usually also have a small + embedded in them.

 

[Skywatcher]

I was looking at Nichicon ES caps at the recommendation of leestereo. I noticed those have bp printed on them. But I can't recall ever seeing them in the 70's Pioneers I've worked on. Did Pioneer use them back then? Or was @Skywatcher's comment just to make me aware that they are in some other audio equipment?

Yes, mostly to be aware, but some Pioneer units do have BP caps in them.

 

[mstewart]

Yes, mostly to be aware, but some Pioneer units do have BP caps in them.

Thank you for pointing this out. Are these caps labeled in any way in the service manuals? Or are they just something one might stumble across unexpectedly? What would happen if I installed a polarized capacitor in place of a bipolar cap? I have been under the impression that it's ok to install a bipolar cap in place of a polarized cap. Is that correct. Isn't that what we're doing when using film caps in place of electrolytic caps? Wow that was a lot of questions in a row! Sorry

 

[Skywatcher]

Thank you for pointing this out. Are these caps labeled in any way in the service manuals? Or are they just something one might stumble across unexpectedly? What would happen if I installed a polarized capacitor in place of a bipolar cap? I have been under the impression that it's ok to install a bipolar cap in place of a polarized cap. Is that correct. Isn't that what we're doing when using film caps in place of electrolytic caps? Wow that was a lot of questions in a row! Sorry

Replacing a polar with a bi-polar will work, but not the other way around.. Things will go POP real fast.. Yes, film caps are non polarized and best used in the signal path..

 

[Skywatcher]

Thank you for pointing this out. Are these caps labeled in any way in the service manuals? Or are they just something one might stumble across unexpectedly? What would happen if I installed a polarized capacitor in place of a bipolar cap? I have been under the impression that it's ok to install a bipolar cap in place of a polarized cap. Is that correct. Isn't that what we're doing when using film caps in place of electrolytic caps? Wow that was a lot of questions in a row! Sorry

Usually in the schematic there is a + designating the positive lead for an electrolytic, and Tantalum capacitor. If there is no +, be aware and look on the board to confirm if a BP is already in there or not.

 

[mstewart]

Replacing a polar with a bi-polar will work, but not the other way around.. Things will go POP real fast.. Yes, film caps are non polarized and best used in the signal path..

Understood. I just quickly read a very short explanation that said in some places a bipolar cap is installed where it may need to handle high positive voltages or high negative voltages.

 

[mstewart]

Usually in the schematic there is a + designating the positive lead for an electrolytic, and Tantalum capacitor. If there is no +, be aware and look on the board to confirm if a BP is already in there or not.

I have observed the + sign on tantalum caps. And I guess coincidentally I have installed a film cap in just about every location where I've pulled one out.

 

[Skywatcher]

Understood. I just quickly read a very short explanation that said in some places a bipolar cap is installed where it may need to handle high positive voltages or high negative voltages.

They are used when you can get reverse biasing. Going from positive to negative will explode a polar cap if the voltage is high enough. Although a polarized cap can take a little reverse voltage with no harm. The datasheets for the caps usually says, but not always.

 

[Skywatcher]

I have observed the + sign on tantalum caps. And I guess coincidentally I have installed a film cap in just about every location where I've pulled one out.

And as you already noticed, most Tantalum caps have the Positive marked instead of the negative. Although some may not so always pay attention to the little details.

 

[mstewart]

They are used when you can get reverse biasing. Going from positive to negative will explode a polar cap if the voltage is high enough. Although a polarized cap can take a little reverse voltage with no harm. The datasheets for the caps usually says, but not always.

I understand. However, haven't spent much time going over data sheets. Lately I have been feeling when I'm recapping one of my stereos that I'm just going through the motions. And using components that someone else chose. My goal is is expand my knowledge as far as I can. So I can have projects beyond recapping old stereos. And I would like to better understand when and where certain caps will sound the best. For example I can't imagine it would make sense to install caps marketed as audio grade in every single location within a stereo. But I dont know enough to be able to say here I'll put this specific cap and there maybe some other one. I've just read that films are best for lower values in the audio path. Low esr is better for power supplies. Ive got a lot to learn!

 

[mstewart]

And as you already noticed, most Tantalum caps have the Positive marked instead of the negative. Although some may not so always pay attention to the little details.

That is good information. The worst thing I could do is get careless like I really know what I'm doing haha. I haven't blown anything up YET. Knocking on wood.

 

[Skywatcher]

I haven't blown anything up YET. Knocking on wood.

It's part of the ritual...

 

[Skywatcher]

I understand. However, haven't spent much time going over data sheets. Lately I have been feeling when I'm recapping one of my stereos that I'm just going through the motions. And using components that someone else chose. My goal is is expand my knowledge as far as I can. So I can have projects beyond recapping old stereos. And I would like to better understand when and where certain caps will sound the best. For example I can't imagine it would make sense to install caps marketed as audio grade in every single location within a stereo. But I dont know enough to be able to say here I'll put this specific cap and there maybe some other one. I've just read that films are best for lower values in the audio path. Low esr is better for power supplies. Ive got a lot to learn!

I personally don't buy into the notion that one needs to use "audio grade" caps. Most modern day "general purpose" electrolytic caps actually meet, or exceed the "audio" caps of days gone by. However certain ones are indeed better in certain spots. I also personally don't care for the "sound" of the Nichicon "Fine Gold" (FG) and prefer to use Panasonic FM, and even FC line of caps. Some places the Silmic II are better to use, but can take weeks to "break-in" and smooth out. Don't just rely on any single thread of a rebuild to follow. Extrapolate from different threads of the same model and take note of people's comments. People's "preferences" and perceptions differ greatly, and ignore the "what sounds better" arguments that always seem to crop up. Heck, I've come across a few units where the factory used ALL "general purpose" caps and they sounded just dandy. Although I myself used "better" modern caps when rebuilding them. The design of the circuity is what gives the "sound signature" more than the "type" of capacitors do. But there is always room for "tweaking" and using better components here and there to "clean up" the signal path. Just remember, YOUR ears are what matters, not someone else's "opinion", including mine.