Why do capacitors sound different?

Comments · 1K

• IP

  @iphooi · 7 years ago

  I'm still really curious about the answer.

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• AL

  @AlanMF00 · 8 years ago

  As a retired analog microchip designer with 35 years of experience, I have a good practical knowledge of capacitor characteristics. Caps have three basic electrical characteristics: capacitance, equivalent series resistance, and equivalent series inductance. Depending on the circuit in which the cap is used, one or more of these might be completely negligible. Film caps have much lower series resistance than electrolytics, but most of the series inductance is in the leads, so there is not much difference between the two types. In audio circuits, resistance and inductance are almost always negligible because the frequency of operation is so low. At audio frequencies, series inductance is practically zero. Series resistance along with the capacitance results in a tiny phase shift of the audio signal, but it&apos;s not at all clear that such tiny phase shifts are audible.<br><br>Rather than providing an explanation, Paul, all you&apos;ve done is <b>declare</b> that film capacitors sound better than electrolytics. To provide an explanation, you would have to deal with the capacitor characteristics I described above, by <b>showing</b> how an audio signal is altered in a way noticeable to the human ear.<br><br>For example, tube amplifiers sound different from transistor amplifiers because tube characteristics are different from transistor characteristics. Almost all audio amplifiers provide gain by using a feedback circuit to control distortion. Tube amplifiers have inherently much lower gain than most decent transistor amplifiers, and end up having much higher distortion, mostly in the odd harmonics, than transistor amps. It&apos;s that distortion that is actually pleasing to the ear, and for poorly known biological reasons, &quot;sounds better&quot; than an undistorted signal. That&apos;s the sort of explanation you would need in order to explain why &quot;film capacitors sound better than electrolytic capacitors. To be thorough, you&apos;d have to provide a representative circuit schematic of some amplifier and explain exactly why using one type of capacitor in one location produces an audio signal that &quot;sounds better&quot; than if using another type.<br><br>Also keep in mind that electrolytics are not used very much in audio circuits (except perhaps very low frequency bass circuits), but almost exclusively in power supply circuits.

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• SH

  @shopmunkey · 3 years ago

  &quot;It&apos;s got what amps crave. It&apos;s got electrolytes&quot;

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• TH

  @thijsdebont · 8 years ago

  That didn&apos;t answer the question. At all.

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• TO

  @tomelmore3993 · 8 years ago

  My background is psychology, so I really appreciate these informal, but informative monologues. Thanks to my fellow listeners for their clarifying commentary, I.e. distinguishing the powers of micro and milli.

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• BC

  @BCToby · 6 years ago

  I feel like the question posed at the beginning was never fully answered. The writer asked if swapping a cheap cap with the same specs as a fancy dancy $$ cap had any audio differences.

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• BE

  @Beelzybud · 8 years ago

  This video doesn&apos;t address the question posed in the title.

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• CA

  @CarsSimplified · 7 years ago

  I wasn&apos;t looking for information about capacitors in an audio-specific set up, but I found myself watching the whole video anyway. Nicely done!

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• RI

  @rickymansfield5487 · 9 months ago

  OMG forget why good component question - after decades of peripheral understanding building kits and replacing capacitors I finally have a clear understanding of what capacitors DO and WHY we need them. &nbsp;I understood how they work in a rectifier circuit but it never made sense to me why that store/discharge function would be necessary in an audio signal path. &nbsp;THIS EXPLAINS SO MUCH! &nbsp;Thank you!

• GR

  @Grobbekee · 8 years ago (edited)

  In short: some caps have more electrical resistance and unwanted inductance than others which could emphasize certain frequencies and diminish others and cause phase shifts. Electrolytic caps have relatively high internal resistance because the electricity passes not only thru metal but also thru this paste with water and salts, which doesn&apos;t conduct perfectly. The chemical reactions inside can also create tiny tiny gas bubbles which when created and vanish create variations in capacitance and resistance that manifest as noise. Because of their build with rolled up foil, they tend to have more inductance also which makes them better suited for low frequencies like filtering the 50/60 Hz out of line voltage. Now if these things are built with great care, these effects are smaller than with cheaper ones. Still, generally one would put a non-electrolytic cap in parallel to short any radio frequency interference.

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• PR

  @prajeeshdev_poonkulanji · 6 years ago (edited)

  THE REASON IS, ESR OF CAPACITORS - See the explanation given below if needed.<br><br>1. Capacitors are meant to block DC and to pass AC.<br><br>2. If the frequency of a signal (or current) is Zero Hertz (the unit of frequency) - &nbsp;it is DC. <br>And if the frequency is One or more Hertz, then it is AC. <br><br>3. We use capacitors with suitable values to block or pass the some frequencies - Higher capacitance values can <br> pass low-freq signals and vice-versa.<br><br>4. The electrical audio signals are AC, varies somewhere between 20Hz to 20,000Hz - Here, the lower frequency signals <br>are supposed to be handled by the Woofers/Sub-Woofers and the higher frequency signals are by Tweeters and the <br>mid frequencies are by Mid-Range speakers. We must pass only the intended frequency range to the respective <br>speaker type, otherwise, it may sound strange.<br><br>5. The mentioned &quot;different sound quality&quot; is mostly observed on the low frequency ranges - here reveals the actual problem.<br><br>6. All capacitors do have ESR (equivalent series resistance - it is an AC resistance, it decreases with increase in frequency) <br>and this parameter will offer some sort of blocking to the lower frequency signals which pass through it.<br><br>7. Since the low frequencies needs much current to be reproduced effectively, the current limiting by ESR will be <br>a villain (bass may not be as deep as expected, with lack of expected current)<br><br>8. Also, in crossover networks, we use capacitors to bypass the unwanted frequencies to ground and to pass only <br><br>the wanted frequencies to output, but, with this ESR, those will not be passed/bypassed effectively, and the <br>speakers which are connected to the output will sound different.<br><br>9. Polypropylene capacitors (the small yellow one shown in the video) are at-least 10 times better than electrolytic <br>caps in terms of ESR and hence those are called &quot;audio-grade&quot;. (Any caps with lower ESR can be audio-grade in fact)

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• MS

  @mserlin · 8 years ago

  A Micro Farad is one millionth of a Farad. Sorry I couldn&apos;t help myself. Thanks for all the great info. Love the vids!

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