Questions tagged [audio]
Questions about designing electronics for measuring, processing, and amplifying audio signals.
3,164
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What is it that strips vocals from audio when a 1/8" audio jack is partially unplugged?
Every once in a while, my eighth-inch audio jack will slip loose and I'll seemingly lose only the voice part of a track -- leaving somewhat of a "karaoke" version. What I would guess about how audio ...
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6
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What is the voltage range of a standard headphone jack from a phone?
I want to connect the output from the audio jack of an iPhone to an Arduino.
What voltage range can I expect to see on the audio lines from the iPhone? I assume that turning the volume up on the ...
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How important is impedance matching in audio applications?
How much will reflected signals matter in audio applications (say between an amp and a speaker, or a pre-amp and an amp)? Mostly with regards to fidelity and not power transfer.
What are the ...
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Loud pop noise while plugging to a headphones jack
I have a Panasonic RX-ES29 boombox with a type C plug (ungrounded). I sometimes hear a relatively loud snap/pop sound in the right speaker of my headphones while I completely plug them into the ...
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How do media buttons on a plain wired headset work?
I mean the simple analog headset pluggable into the jack of a phone. Not USB, not bluetooth, not fancy proprietary plugs with extra connectors - just a generic stereo+mic jack.
The four "bands" on ...
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6
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Can an audio circuit be powered by a switched-mode power supply?
Most audio circuits are powered with large, heavy transformers and a small ripple after smoothing. SMPS are smaller and more efficient. EMI can be shielded by a metal enclosure and the output filtered ...
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What makes a "balanced" audio signal?
What is "balanced" audio exactly, and why is it useful? I've read that it means there are two voltages, with one being the inverse of the other. A balanced audio receiver looks at the difference ...
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Are audio cassettes FM or AM?
I know that cassettes store an analog signal, but is the signal Amplitude-Modulated (AM) or Frequency Modulated (FM)?
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6
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Normal capacitor vs. audio capacitor
I'm building a power supply for old Schoeps CMT30F microphones. Standard condenser mic are 48V-powered nowadays, but these are 60s/70s Schoeps mic from RadioFrance/ORTF, customized at that time to be -...
- 1,886
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What set the speed in a cassette tape recorder?
I was wondering what set the rotational speed in a cassette recorder? I assume that the speed must be constant, but that means that the tape data would have different effective densities depending on ...
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What's the best cable to transfer audio signal?
Sorry if this is the wrong place but I'm interested in a scientific and electrical explanation and not some HiFi voodoo magic.
I guess you all have seen the discussions about expensive audio cables ...
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Where do overtones in a 555 generated square wave come from?
I have built a 555 oscillator and connected it to a speaker.
Using an oscilloscope I adjusted the 555 to generate a 2.5kHz square wave.
I then held a microphone up to the speaker and fed the input ...
- 593
22
votes
1
answer
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Optical audio transmitter can't handle speech
This is a question relating to my project on an optical audio transmitter.
I wired up a very simple device in which I use an audio signal transformer (EI14) to modulate the intensity of a laser beam (...
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22
votes
2
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Single supply op-amp audio amplifier
I am trying to create an op-amp amplifier that would work from single 5V supply, and would be able to amplify -100mV to +100mV audio signal to around a 1V peak-peak or so. I've came across this ...
- 1,967
22
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DC biasing audio signal
I have seen a few different ways of adding DC bias to an audio signal. I have simulated them and they all give me similar results, but I can't figure out why choose A over B or C. My audio source will ...
- 2,510
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White hairs inside a headphones cable
I have a cheap set of Phillips SHE3000 earphones with a broken wire on the plug. Since I was repairing another set of headphones, with the same problem, I bought an extra plug, just to try repairing ...
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20
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How does the phone detect if 3.5 mm jack circuit is closed?
I have an android phone to which i have plugged an earphones. So at the top of the phone, I get the headphone symbol which indicates that the earphone is connected (In other words, the circuit at the ...
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4
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How does an audio jack detect when a speaker is plugged in?
Some sound card audio jacks can now inform recent Windows OS's that an audio device is plugged in. Anyone know how it does this? I'm thinking it uses some kind of voltage comparator or resistance ...
- 303
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6
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Paper in oil (PIO) capacitors: what is special?
Many audio circuits use PIO capacitors. What are the electrical Characteristics of PIO caps that make them special (i.e. justify the cost)? Which parts of an amplifier circuit benefit most from the ...
- 1,281
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4
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How could you transfer data over an audio line?
I'd like to pass some data over an audio cable (i.e from audio card to my cellphone) with a short cable.
I'm looking for some ideas for algorithms for achieving this. They of course should include ...
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What wattage should a headphone amp be?
I was at a local surplus store today and I got two LM386N ICs. I thought I could make a really simple headphone amp out of these. But I have no idea what the wattage of a normal headphone amp is.
...
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Simple Audio amplifier Using Transistors
I would like to build a simple audio amplifier using transistors. I know there are IC designs specifically for the task. But i want to use transistors so i can learn how to use them for amplification.
...
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18
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7
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Over what frequency range can the microphone of smartphone receive the sound? [closed]
I have a project in which I am considering using the microphone from a smartphone for the reception of inaudible signals (> 15khz).
What is the frequency range that such a microphone of receive sound?...
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Using a microphone with an Arduino
EDIT: I have been investigating in this problem for quite some time. It turns out to be a way more difficult project than I thought and not something for beginners. This requires expensive hardware (...
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3
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Why does this op amp stop working after some time?
I have an audio streaming device I bought that has analog audio output that is way too low (it’s supposedly line level, and I’m not the only one who’s complained about this).
I’ve been using this as ...
- 1,553
17
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9
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DSP recommendation for beginners [closed]
I am considering a project involving a fair share of digital signal processing. As far as I know, the best type of IC suited for this are the Digital Signal Processors. I have never worked with them ...
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5
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How different can the digital signal from a low-cost CD player be from that of an expensive Hi-Fi CD player?
According to the high-end Hi-Fi connoisseurs' bibles, for a perfect reproduction of the sound, in addition to "special cables", etc., you must have a specialized stage of CD which reads the ...
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4
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What is the advantage of optical TOSLINK over RCA coaxial cable?
A popular standard for the transmission of digital audio between audio devices has been the AES3 standard (also known as S/PDIF). The standard sends stereo PCM audio and of often found in consumer ...
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2
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Audio using PWM, what is the principle behind it?
I have seen a schematic of a PIC board which uses filtered PWM to provide audio output signal to an audio jack. It shows PWM output filtered using 3 stages of passive RC filter followed by an LM386 ...
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16
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5
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Why are high end audio connections gold?
Silver has a lower resistivity than gold and is cheaper, so why are high end audio components gold plated?
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Cable shielding adequate for video, but not audio frequencies
I am no expert in audio equipment, but to educate myself I have been studying. In the process, I came across a video which tests the audio frequency shielding of a purported shielded video cable. (I ...
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4
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Can a power MOSFET for switching application be used as a linear amplifier?
Power MOSFETs nowadays are ubiquitous and fairly cheap also at retail. In most datasheet I saw power MOSFETs are rated for switching, without mentioning any kind of linear applications.
I'd like to ...
16
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2
answers
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Can anybody identify this component (SPRAGUE 663044-4) on this vintage electronic?
I am repairing a vintage Seeburg/Gulbransen 'Select-a-Rhythm' drum machine from 1967, the kind you would sit on top of your organ and play along with.
I am trying to distinguish what this component ...
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6
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Why do (microphone) preamp designs tend to limit opamp gain to max 60 dB?
Looking at many pro recording quality microphone preamps, I noticed that every design I looked at that uses an opamp (discrete or IC) limits the gain provided by the opamp to about max 60dB. While ...
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How are speakers matched with audio amplifiers? (avoiding overloading either)
I know a similar question title has been asked, but I believe that does not answer my question (and I couldn't think of a better way to phrase the question).
I'm a bit confused by how exactly an amp ...
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12
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Polyphonic sounds from a microcontroller?
I can make monophonic sounds by toggling a single pin (at a varying rate) connected to a piezo buzzer.
How can I generate two mixed audio signals in software to create polyphony?
Here's the code I'm ...
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Why are these two electrolytic capacitors so hugely different in size?
I'm recapping a vintage amp, and that amp has two larger caps at 2200uF @ 50V. I have sourced some possible replacements, and I'd like some insight into why these are SO different in size, and how I ...
- 1,585
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Understanding Audio Jack Connection
I have circuit that has an audio connector that has the following diagram.
Audio connector is one that I am not familiar with. What I gather is that the rectangle on the left is the sleeve (entry ...
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14
votes
6
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Legality of Reverse Engineering
If there was a "law/legal" stack exchange site I'd post it there, but it's in its infant stages in Area 51. I'm a musician and an electrical engineering student. I've designed a modification to the ...
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2
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Naively mixing two (or perhaps more) audio signals
this is my first question and I am very much a beginner in electronics so I apologize if this is a too stupid question.
I have Atari punk console and another small homemade audiomaking circuit. These ...
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5
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How to create large inductors (1H) for audio use?
I am building a tube amplifier, and have decided to add a 5ch EQ to it. Historically, the ones used in guitar amplifiers were all passive RLC filter style systems, with large inductances of 0.5 - 2H ...
- 3,526
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Audio delay using discrete components
I would like to make a circuit that causes an audio delay using discrete components.
I know I can do small phase shifts using an opamp, but I am looking for something in the millisecond or second ...
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14
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Want a USB mini-microphone array. Is it possible?
I have been learning a lot about adaptive beam-forming, and have been mucking around with various sims in MATLAB, etc.
But what better way to understand something - truly understand it - than to ...
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Accidentally downmixed stereo to mono, why does this work?
I have a cheap Chinese Bluetooth audio amplifier like this:
It has four screw terminals for the speaker connections, namely L+, L-, R+ and R-. I accidentally connected a single speaker to L+ and R-, ...
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13
votes
4
answers
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Best transistor to use for audio amplifier
This term, we will be designing an audio amplifier. So far in our lecture, we are still at BJT and based from what I've heard, FETs will just be partly discussed unlike the thorough one on BJT. Anyway,...
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Building a synthesizer with no prior experience
I've got an extensive music background and have been infatuated with synthesizers since I was young. I had dreamed of going into an EE program to make my dream a reality, but I couldn't afford school (...
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4
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How do those 3.5mm stereo to mono adapters work?
I have one of those 3.5mm Female Mini-phone mono to Mini-phone stereo which I was hoping to use for connecting the output of an MP3 player (stereo) to a pillow speaker (mono).
But then it occurred to ...
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The Pin 1 Problem in Audio, Star and Mesh Ground, and Contradictory Grouding Practices in Audio and Digital Systems
I recently came across the concept of "Pin 1 Problem" known in the pro-audio electronics. It seems straightforward at first, but becomes confusing when it comes to grounding. Let me describe ...
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1
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Will this passive non inverting anti-log circuit work?
The potentiometer on the left of the circuit below is actually the output of a digital potentiometer designed for audio volume control, so its outputs are internally configured to offer 64 logarithmic ...
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5
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2-layer PCB design, through hole technology and ground plane
I am designing the layout of a PCB for audio applications (no digital electronics, only analog).
All components are through hole, the PCB is pretty large (about 16cm x 10cm) and has 2 layers. Plated ...
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