RE: Could electrolytic capacitors in the signal path be a myth? - Jim McShane 19:06:21 12/14/15 And a variety of WIMA and Clarity, Solan film caps. I am using audio grade Nichicon KT, KW,FW ,FG series caps. But every time the polar cap does sound better. Granted I am usually upgrading the quality of THAT cap. However, this is the fourth or fifth project that I've tinkered with, trying a variety of capacitors and every time I keep coming back to the electrolytics. I would be conservative and double this total value - higher values sometimes come in the same size package, have a lower ESR (a good thing) and will be less likely to fail in case other components in the circuit fail.Seems like every time a posting about signal path capacitors comes up electrolytic capacitors are universally condemned! To choose a voltage ratings, you need to consider the bias voltage plus the AC voltage swing of the audio signal. The value of your capacitor will be determined by the impedance of the circuit and the desired low-frequency response. I have also had a great deal of trouble with the SMD versions of these parts surviving assembly and reflow using standard automated assembly techniques. While they are stellar performers, they are very large in size for the rated value. You will also see some references to film capacitors for use as AC coupling in audio. NP0 and C0G are the best of the ceramics, however I don't think you will find these types available in appropriate values. We have also found that ceramic capacitors suffer from microphonic effects: the audio passing through the part will actually physically resonate and cause distortion! I would only use ceramic capacitors in the audio path where performance is not an issue, but size and cost are your higher priority. However, when most ceramic capacitors are biased, the capacitive rating can decrease by as much as 50%! The higher grade (X7R) types suffer less from this, but you should be aware that a 1 uF might be acting like a 0.68uF in the circuit. They are attractive because of the size, cost and low ESR. They are generally smaller than electrolytics for the same value.īoth of the non-ceramic types will hold their capacitive value under use condition, unlike ceramics.Ĭeramic capacitors are generally not recommended for use as AC coupling in audio. On the positive side, tantalums do not dry out and so are appropriate for a long term high temperature environment. Some people say they "don't sound as good," however static single-tone distortion tests might not reveal any differences. As polarized capacitors, they must also be biased, however I have not found them to be as linear in an audio path as electrolytic capacitors. Tantalum capacitors are a reasonable alternative, however they are more expensive than electrolytics and are not available in as many values. High temperature versions are available and will hold up well over a long period of time. They literally 'dry out' and become a high pass filter in the signal path. However, electrolytic capacitors have quite a large footprint and they will suffer from degradation of value and performance over time - especially in a high temperature environment. They are very linear when biased by the Common Mode voltages present in most SigmaDSP audio paths and their low ESR (Equivalent Series Resistance) makes them attractive as an 'invisible' component when designing a circuit. Each has strengths and weaknesses.Įlectrolytic capacitors are generally the best performing for this purpose. In general, there are 3 types of capacitors that will be available in the values that are appropriate as AC coupling in most signal paths: electrolytic, tantalum and ceramic. Thank you for your inquiry about capacitors in the audio path around our SigmaDSP parts.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |