Timeline for DC biasing audio signal
Current License: CC BY-SA 4.0
16 events
| when toggle format | what | by | license | comment | |
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| May 14, 2020 at 16:15 | history | edited | endolith | CC BY-SA 4.0 |
clarify pop sunds
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| May 14, 2020 at 16:13 | comment | added | endolith | @SouravGhosh Ah, yes, I'll clarify | |
| May 14, 2020 at 9:49 | comment | added | Sourav Ghosh | @endolith Thank you very much. Now it is quite clear. I also visited your circuit simulation, removed the input and the resistor, decreased simulation speed, and verified this behavior. At first, I was confused after reading your answer because I thought you were talking about capacitor popping (i.e, destruction of the capacitor). Now I understand that it is the 'pop' sound that we get sometimes after connecting a speaker. | |
| May 13, 2020 at 19:50 | comment | added | endolith | @SouravGhosh If that resistor weren't there, and the input was not yet connected, and you turned on the power, then both sides of the capacitor would rise at the same time until they were at Vbias=2.5 V. If you then connected a device that had an output resistance of 100 Ω, for instance, connected to ground, then the input side of the capacitor would be instantly pulled close to 0, causing the output of the capacitor to jump to 0 as well, producing a pop sound. Then the capacitor would slowly charge through the 100 Ω and 10 kΩ resistors until the input was 0 and the output was 2.5 V | |
| May 13, 2020 at 16:38 | comment | added | Sourav Ghosh | @endolith "The resistor on the input ensures that the input side of the capacitor is at 0 VDC, to prevent pops during connection." can you please explain it a little bit more for me? is this to discharge the capacitor? why it may pop? what will happen if I leave it? Sorry if the questions are silly. | |
| Jul 16, 2018 at 15:33 | history | edited | endolith | CC BY-SA 4.0 |
update circuit simulator links
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| Apr 10, 2018 at 16:38 | comment | added | endolith | @SpaceDog My first circuit does not filter power supply noise. I said underneath that it's only ok "If your circuit already has a clean, low impedance DC bias voltage source" | |
| Apr 10, 2018 at 2:29 | comment | added | Duck | You say that the OP's first circuit will have the power supply noise amplified but your first circuit has the power supply directly connected to the output. Ins't a capacitor missing there? How is the first circuit filtering the power supply AC (noise)? | |
| May 23, 2011 at 14:06 | comment | added | endolith | @jsolarski: It'll be like any audio mixer input, then. You'll need some variable gain control for the unpredictable low-level inputs, and maybe separate jacks for the line-level, depending on the connectors you want to use. For a BPM counter, low-noise probably isn't that important, so you could just use a single op-amp gain stage with a wide gain range. Alternately, a narrower gain range and a 20 dB pad switch. | |
| May 23, 2011 at 6:25 | vote | accept | jsolarski | ||
| May 23, 2011 at 6:25 | comment | added | jsolarski | as to my earlier comment, I will have to post another question when I get to that point, my concern is I have multiple signals, some are line level and some will be very low level mic inpputs or phono inputs. I just need a way to keep the levels in the same range, when plugging in different sources. | |
| May 19, 2011 at 14:19 | comment | added | endolith | @jsolarski: I don't understand your question about the preamp. That circuit is a high-gain mic element preamplifier. Are you just looking to buffer the signal before it goes into the ADC? | |
| May 19, 2011 at 7:47 | comment | added | jsolarski | As for the pre-amp would that circuit bias signal if I were using a un-amplified(phono) signal or microphne? or should it just go through a pre-amp that doesnt bias and bias the signal near the filter? | |
| May 18, 2011 at 15:30 | history | edited | endolith | CC BY-SA 3.0 |
added 695 characters in body
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| May 18, 2011 at 15:20 | history | edited | endolith | CC BY-SA 3.0 |
added 516 characters in body
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| May 18, 2011 at 15:12 | history | answered | endolith | CC BY-SA 3.0 |