| Author |
Message |
Dave
Guest
|
 Posted:
Tue Nov 29, 2005 12:34 am Post subject:
polar vs nonpolar capacitors |
|
|
I am interested in upgrading some audio components, and a lot of DIY tweak
mention "replace the electrolytics in the signal path with Black Gate or
other low-noise nonpolar capacitors." I know that polar capacitors cannot
tolerate reversed polarity, and that bi-polars can as they are really two
back-to-back capacitors. What is a non-polar? How is it different from a
bipolar?
Dave
|
|
| Back to top |
|
 |
Michael Black
Guest
|
| Posted:
Tue Nov 29, 2005 1:26 am Post subject:
Re: polar vs nonpolar capacitors |
|
|
"Dave" (dspear99ca@yahoo.delete.com) writes:
| Quote: | I am interested in upgrading some audio components, and a lot of DIY tweak
mention "replace the electrolytics in the signal path with Black Gate or
other low-noise nonpolar capacitors." I know that polar capacitors cannot
tolerate reversed polarity, and that bi-polars can as they are really two
back-to-back capacitors. What is a non-polar? How is it different from a
bipolar?
Dave
|
Well, it must be a non-polarized capacitor.
Polarized capacitors exist not because of function but because of
manufacturing process.
There is no need for polarized capacitors.
But, in order to have higher value capacitors in reasonable sized
packages, the manufacturers have to switch to methods that result
in a polarized capacitor. The capacitor itself objects if the
wrong polarity is applied.
For a lot of applications where higher value capacitors are required,
that they are polarized doesn't matter, because they are mostly used
where there is indeed a well defined DC voltage applied to one of
the terminals. Thus, for filter capacitors in that power supply,
a polarized capacitor doesn't matter because you connect the capacitor
from a positive voltage to ground, so it's all very clear. A coupling
capacitor on the output of an amplifier running off only a positive
voltage has a positive voltage on that output, so again it's clear.
In a few cases, the capacitor won't actually see a clearly polarized
voltage source. Crossover capacitors in speakers are a prime example,
because the DC component has already been removed, either because
the amplifier feeding the speaker has a DC coupling capacitor on
the output, or has a transformer on the output (not likely in recent
decades). Here, there is no longer an AC voltage riding on a DC voltage,
so no matter what the AC voltage one side of the capacitor is clearly more
positive than the other; there is an AC voltage coming into that capacitor,
moving from positive to negative and back, in reference to the other
side of the capacitor. You need a non-polarized capacitor there, but
the issue of size and capacitance comes into play, and most capacitors
of the values needed will be electrolytic. A common trick is to put
two polarized capacitors in series, and sometimes they are manufactured
that way, so the capacitor is not polarized.
But there are issues with that sort of scheme. For someone fussing
with types of coupling capacitors in audio circuitry, they want non-polarized
capacitors. Thus the capacitors need to be manufacturered using some scheme
that will not inherently result in a polarized capacitor. If the values
are low enough, this is not an issue. If the values of capacitance are
higher, then one has to hunt around capacitors of mylar or polystyrene or
some other scheme that does not result in a polarized capacitor, and
the result may be a larger capacitor because those other formulations
can't be so compact.
Michael |
|
| Back to top |
|
|
John Larkin
Guest
|
| Posted:
Tue Nov 29, 2005 9:17 am Post subject:
Re: polar vs nonpolar capacitors |
|
|
On Mon, 28 Nov 2005 18:34:46 GMT, "Dave" <dspear99ca@yahoo.delete.com>
wrote:
| Quote: | I am interested in upgrading some audio components, and a lot of DIY tweak
mention "replace the electrolytics in the signal path with Black Gate or
other low-noise nonpolar capacitors."
|
Ignore this silliness. A non-broken electrolytic capacitor is not
noisy.
John
|
|
| Back to top |
|
|
PeteS
Guest
|
| Posted:
Tue Nov 29, 2005 9:35 am Post subject:
Re: polar vs nonpolar capacitors |
|
|
John Larkin wrote:
| Quote: | On Mon, 28 Nov 2005 18:34:46 GMT, "Dave" <dspear99ca@yahoo.delete.com
wrote:
I am interested in upgrading some audio components, and a lot of DIY tweak
mention "replace the electrolytics in the signal path with Black Gate or
other low-noise nonpolar capacitors."
Ignore this silliness. A non-broken electrolytic capacitor is not
noisy.
John
|
More audiophools?
Cheers
PeteS |
|
| Back to top |
|
|
Pooh Bear
Guest
|
| Posted:
Tue Nov 29, 2005 3:44 pm Post subject:
Re: polar vs nonpolar capacitors |
|
|
Dave wrote:
| Quote: | I am interested in upgrading some audio components, and a lot of DIY tweak
mention "replace the electrolytics in the signal path with Black Gate or
other low-noise nonpolar capacitors." I know that polar capacitors cannot
tolerate reversed polarity, and that bi-polars can as they are really two
back-to-back capacitors. What is a non-polar? How is it different from a
bipolar?
|
Non-polar electrolytics are 2 polar elctrotytics back to back in a single
case.
The validity of the benefit of black gate caps may be judged by the fact that
they are no longer in production.
Many circuits will benefit simply by fitting a larger value electrolytic
coupling cap when operated 'zero-biased'. The reason is sufficiently
complicated for me to leave it out of here for now.
Caps don't make noise - so there's no such thing as a low noise capacitor.
Most audio nuts are simply blowing out of their arseholes.
Graham |
|
| Back to top |
|
|
Pooh Bear
Guest
|
| Posted:
Tue Nov 29, 2005 3:46 pm Post subject:
Re: polar vs nonpolar capacitors |
|
|
Michael Black wrote:
| Quote: | For someone fussing
with types of coupling capacitors in audio circuitry, they want non-polarized
capacitors.
|
Most pro-audio equipment uses large value coupling electrolytics in zero-bias
conditions !
Ever wondered why ?
Graham |
|
| Back to top |
|
|
Jasen Betts
Guest
|
| Posted:
Tue Nov 29, 2005 5:01 pm Post subject:
Re: polar vs nonpolar capacitors |
|
|
On 2005-11-28, Dave <dspear99ca@yahoo.delete.com> wrote:
| Quote: | I am interested in upgrading some audio components, and a lot of DIY tweak
mention "replace the electrolytics in the signal path with Black Gate or
other low-noise nonpolar capacitors." I know that polar capacitors cannot
tolerate reversed polarity, and that bi-polars can as they are really two
back-to-back capacitors. What is a non-polar? How is it different from a
bipolar?
|
no different, In this case 2=0
Bye.
Jasen |
|
| Back to top |
|
|
Noway2
Guest
|
| Posted:
Tue Nov 29, 2005 5:35 pm Post subject:
Re: polar vs nonpolar capacitors |
|
|
| Quote: | Most audio nuts are simply blowing out of their arseholes.
|
You mean to tell me that you can't hear the missing music on aCD from
the digitization process?? I am crushed! |
|
| Back to top |
|
|
PeteS
Guest
|
| Posted:
Tue Nov 29, 2005 5:35 pm Post subject:
Re: polar vs nonpolar capacitors |
|
|
Noway2 wrote:
| Quote: | Most audio nuts are simply blowing out of their arseholes.
You mean to tell me that you can't hear the missing music on aCD from
the digitization process?? I am crushed!
|
Shhhhhh
Next thing you know, they'll be complaining that the EFM encoding
introduces noise unless read by a gold tabbed laser - only that would
be good enough for audiophools.
Cheers
PeteS |
|
| Back to top |
|
|
Paul Burridge
Guest
|
| Posted:
Tue Nov 29, 2005 5:35 pm Post subject:
Re: polar vs nonpolar capacitors |
|
|
On 29 Nov 2005 05:26:14 -0800, "PeteS" <ps@fleetwoodmobile.com> wrote:
| Quote: | Noway2 wrote:
Most audio nuts are simply blowing out of their arseholes.
You mean to tell me that you can't hear the missing music on aCD from
the digitization process?? I am crushed!
Shhhhhh
Next thing you know, they'll be complaining that the EFM encoding
introduces noise unless read by a gold tabbed laser - only that would
be good enough for audiophools.
|
Not sure about "gold tabbed" but certainly if your laser isn't
'silvered' with sputtered gold, your listening pleasure will be marred
by quantisation noise, as any audiophallic will tell you.
--
"What is now proved was once only imagin'd" - William Blake |
|
| Back to top |
|
|
John Larkin
Guest
|
| Posted:
Tue Nov 29, 2005 5:35 pm Post subject:
Re: polar vs nonpolar capacitors |
|
|
On 29 Nov 2005 00:52:44 -0800, "PeteS" <ps@fleetwoodmobile.com> wrote:
| Quote: | John Larkin wrote:
On Mon, 28 Nov 2005 18:34:46 GMT, "Dave" <dspear99ca@yahoo.delete.com
wrote:
I am interested in upgrading some audio components, and a lot of DIY tweak
mention "replace the electrolytics in the signal path with Black Gate or
other low-noise nonpolar capacitors."
Ignore this silliness. A non-broken electrolytic capacitor is not
noisy.
John
More audiophools?
|
Yup. You can send in your old Heathkit or Macintosh whatever tube amp
to folks who will replace all the caps with Black Beauties or silver
foil or whatevers, at huge expense.
John |
|
| Back to top |
|
|
Michael Black
Guest
|
| Posted:
Tue Nov 29, 2005 5:35 pm Post subject:
Re: polar vs nonpolar capacitors |
|
|
John Larkin (jjlarkin@highNOTlandTHIStechnologyPART.com) writes:
| Quote: | Yup. You can send in your old Heathkit or Macintosh whatever tube amp
to folks who will replace all the caps with Black Beauties or silver
foil or whatevers, at huge expense.
John
About a decade ago, I got a catalog from a place here in Canada |
that did that sort of upgrade, and sold parts to do it yourself. I
must have sent for the catalog thinking it might be a source of parts.
The catalog arrives, and the prices on the components were outrageous.
I think the capacitors were going for a couple of dollars each.
Obviously, not a source for parts in Canada. And I still don't know
if the parts they sold actually were expensive, or they just did
a massive markup on them.
Michael |
|
| Back to top |
|
|
jfeng@my-deja.com
Guest
|
| Posted:
Tue Nov 29, 2005 11:48 pm Post subject:
Re: polar vs nonpolar capacitors |
|
|
Pooh Bear wrote
| Quote: | Non-polar electrolytics are 2 polar elctrotytics back to back in a single
case.
|
In this context, I think they mean non-electrolytic non-polar
capacitors.
Bob Pease of National Semiconductor and Electronic Design magazine has
asserted that tantalum electrolytic capacitors may introduce audible
distortion due to dielectric absorption effects (and he regularly mocks
the Golden Ear crowd). He refers to this in his article "What's all
this soakage stuff, anyhow?" which can be found at
http://www.elecdesign.com/Articles/ArticleID/6096/6096.html
I seem to recall an earlier article by him from the 1970s where he
found that an amplifier with tantalum coupling capacitors sounded
terrible, but it was fine after he replaced them with aluminum
electrolytics. I can't find that article on the internet, and I am
sure that I have thrown away that issue of the magazine.
If this argument is correct, then it might also apply to ceramic
capacitors with high-k dielectrics. |
|
| Back to top |
|
|
Michael Black
Guest
|
| Posted:
Tue Nov 29, 2005 11:51 pm Post subject:
Re: polar vs nonpolar capacitors |
|
|
John Larkin (jjlarkin@highNOTlandTHIStechnologyPART.com) writes
| Quote: | Yup. You can send in your old Heathkit or Macintosh whatever tub
am
to folks who will replace all the caps with Black Beauties or silve
foil or whatevers, at huge expense
Joh
About a decade ago, I got a catalog from a place here in Canad
that did that sort of upgrade, and sold parts to do it yourself. |
must have sent for the catalog thinking it might be a source of parts
The catalog arrives, and the prices on the components were outrageous
I think the capacitors were going for a couple of dollars each
Obviously, not a source for parts in Canada. And I still don't kno
if the parts they sold actually were expensive, or they just di
a massive markup on them
Michae |
|
| Back to top |
|
|
John Fields
Guest
|
| Posted:
Wed Nov 30, 2005 1:35 am Post subject:
Re: polar vs nonpolar capacitors |
|
|
On Tue, 29 Nov 2005 09:44:46 +0000, Pooh Bear
<rabbitsfriendsandrelations@hotmail.com> wrote:
| Quote: | Caps don't make noise - so there's no such thing as a low noise capacitor.
|
---
That's not true.
Just for single example, many ceramic caps with hi-k dielectrics are
microphonic _and_ parametric.
--
John Fields
Professional Circuit Designer |
|
| Back to top |
|
|
|
|
|
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in