polarized caps in audio path?

Discussion in 'General Electronics Chat' started by Joel Vasquez, Oct 18, 2014.

  1. Joel Vasquez

    Thread Starter New Member

    Oct 17, 2014
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    i am currently replacing all the caps on a piece of audio gear in hopes of improving sound preformance. My question is can I use polarized electrolytics in the audio path? Currently there are bi polar electrolytics (cheap Chinese) and I'd like to replace them with better quality Nichicon caps. Nichicon carries the muse series bipolar caps (the green ones) but I've heard of the FW series sounding great.
     
  2. MrChips

    Moderator

    Oct 2, 2009
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    Forget about different caps sounding great. That is a myth.

    You can use polarized caps in the audio path. Just observe the polarity when you install them. Connect the -VE lead of the cap to the more negative side of the circuit.

    Personally, you are going to be disappointed.
     
  3. Joel Vasquez

    Thread Starter New Member

    Oct 17, 2014
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    What do you mean by the most negative side of the circuit?
     
  4. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    There are two points. One point will have higher voltage then the other. The point with higher voltage is where positive leg of the cap goes. Negative leg of the cap goes to the other point.
     
  5. crutschow

    Expert

    Mar 14, 2008
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    Unless one of the caps is bad, it's unlikely that replacing all the caps will have a noticeable effect on the sound quality.
     
  6. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    I'm sure that after all of that work that you can convince yourself it was an improvement.

    Also,
    Are there expensive things in China? I know there are good quality things made in China like iPhones so I am sure you are not talking about quality. Where is your Amp made?
     
  7. Joel Vasquez

    Thread Starter New Member

    Oct 17, 2014
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    So i woul measure both sides of the circuit by removing the cap and measuring where each lead would go?

     
  8. Joel Vasquez

    Thread Starter New Member

    Oct 17, 2014
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    Its not an amp. Its a tube AND solid state audio processor. I did also switch out the op amps. The stock ones were MC33079 and I replaced them with the OPA1654. I guess what I meant by the caps "sound" was their ability to handle certain frequencies. I'm trying to clean up the sound and get more depth out of my audio signals that are being processed. There are no A/D or D/A converters or any other digital components.
    Sorry if I sound like a newbie but I kind of am! Thank you guys for your feedback. Any would be appreciated. Good or bad!
     
  9. MrChips

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    Oct 2, 2009
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    You don't have to remove the present cap. Measure the voltage across the cap and pay attention to the polarity.
     
  10. Joel Vasquez

    Thread Starter New Member

    Oct 17, 2014
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    Ahhhhh I see! Thank for the advice!
     
  11. MrChips

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    Caps provide a certain amount of frequency compensation.
    Many caps installed in circuits have 20% tolerance.

    Hence if you replace the cap you could change the frequency response by as much as 40%. That is what you are likely to hear, not a result of better quality caps.

    For example, suppose the current cap is off from the stated value by -20% and you replace it with one that is +20%, you may experience a more mellow tone because you have lowered the cut off frequency of the circuit. You could easily be fooled into believing that that was improved sound.

    Like the audiophools who swear by nitrogen-filled cables.
     
    Last edited: Oct 18, 2014
  12. Joel Vasquez

    Thread Starter New Member

    Oct 17, 2014
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    I read somewhere that in order to reproduce all frequencies audible to the human ear, a minimum 10uf cap is required. How else could I improve the sound of this unit? I know it's almost impossible to ask since you have no clue what it looks like much less a schematic. But what are some things I could look for either on scope or on the board?
     
  13. MrChips

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    Oct 2, 2009
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    And what you read is WRONG.

    Learn electronics and you will know that that is an absurd statement to make.
     
  14. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    The required min. value of a capacitor in an audio circuit is based on the other components that the capacitor is wired to. The required value (for high fidelity reproduction of music) could be anywhere from 10s of pF to 100s of uF.

    My electronics-challenged son-in-law fancies himself as an audiophile. He has more money than brains. Unfortunately, he is one of those who believes the hype about oxygen-free-copper speaker wires. I surreptitiously substituted 18awg doorbell wire, and it took weeks for him to notice...
     
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  15. Lestraveled

    Well-Known Member

    May 19, 2014
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    Hearing is subjective. It is colored by how we feel and what we think at the moment. We choose what we are going to like. A man of science will read the electronic specs of an amplifier and say to himself,"This is a good amp" and as a result, he will hear wonderful music from that amp. Another man will read that an amplifier used a certain kind of capacitor and he will say to himself, "This is a good amp" and also hear wonderful music. What you like is your personal choice. "I don't know art, but I know what I like" (Monte Python) is actually a very knowledgeable statement.

    There is no science that supports the claim that one kind of capacitor is better for audio than another, but if it make you "like" your sound system more, then go for it. Luckily, the performance standard for amplifiers now days is very high compared to 20 years ago, so, no matter what determines your criteria, you will probably get a great amp.
     
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  16. crutschow

    Expert

    Mar 14, 2008
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    Most capacitors in an audio amp are either coupling caps or filter caps. Coupling caps are generally sized so they have no appreciable effect on the frequency response within the tolerance of the cap. So changing caps that haven't failed will have little effect on the response as long as the caps are at least as large as the originals.
    I have read about some audionuts saying that capacitors that have dielectric absorption (soakage), as some high-k ceramics have, can cause distortion but I think that effect, even if it occurs, would be so small as to be undetectable, at least for coupling capacitors.
     
  17. KeepItSimpleStupid

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    Mar 4, 2014
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    A lo of the cheap sold state stuff use some 10 uf, 1 uf and 0.1 uf electrolytic int he audio path. They fail more often in my opinion. The metalized polyester in that range are much more expensive.
     
  18. studiot

    AAC Fanatic!

    Nov 9, 2007
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    One difference between electrolytic (polarised) and non polarised capacitors is thier relatively high leakage which leads to pops and other noise.

    This is not necessarily an 'in audio path' effect but due to charging and discharging of the cap through the leakage resistance.

    The effect gets worse with the age of the capacitors and their life history. Electrolytics need to be kept charged so if the eqipment is switched off for long periods they deteriorate.

    A side note. The word polarised refers to the fact that the capacitor (or other component) should be connected into circuit in a particular orientation. The + and - refers to that orientation.
    Capacitors only become electrically polarised when they are connected to a (suitable) live circuit and all capacitors will be charged to the same voltage in the same circuit, though not all circuits actually charge the capacitor in operation. By this I mean that polarised capacitors need a direct polarising voltage to be supplied as well as the alternating signal voltage. It is the polarising voltage that introduces the unwanted signals.

    Capacitors are referred to as polarised or non polarised in this sense. Bi polar capacitors are a different component that have three terminals, usually seen on old fashioned power supplies.

    Normal capacitors are two terminal devices.
    Polarised capacitors have one terminal marked + and sometimes the other is marked -.
    they should be connected as already indicated.
    Non polarised capacitors have no such markings and may be connected either way round.
     
  19. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    Which, by the way, have another staisfying application.

    tender.jpg
     
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  20. Joel Vasquez

    Thread Starter New Member

    Oct 17, 2014
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    LOL
     
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