Questions tagged [audio]

Questions about designing electronics for measuring, processing, and amplifying audio signals.

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29
votes
2answers
10k views

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 ...
0
votes
1answer
39 views

Designing a circuit for TRRS Socket

I'm building an electronic musical instrument which I would like it to have a 3.5mm audio output socket, so it would work with any "regular" headphones, like a cellphone does. For a long time, I've ...
0
votes
3answers
2k views

TDA7492p 50W+50W

I'm thinking of making a portable Bluetooth speaker using this module. I have some speaker and tweeter combos from a cheap old 5.1 home theater system (cjc 690r). I want to be able to connect any ...
1
vote
1answer
26 views

LM4871 audio amplifier BTL configuration question

I am reading the datasheet of LM4871 audio amplifier. The typical application looks like: The datasheet says it is in BTL configuration. The 1st OPA inverts input signal and the 2nd OPA inverts again ...
0
votes
1answer
28 views

Can multiple looper ICs (ISD1820) share one single electret microphone?

I'm using multiple of these ICs to create a simple audio looper. Can they share the same single electret microphone, or should they each have their own? Multiple ICs may have brief overlap of use of ...
1
vote
2answers
148 views

Vibrato audio effect circuit [closed]

I would like to build a circuit that adds a "vibrato" audio effect to a simple sine wave input. Sample audio clip from Wikipedia: Vibrato, Sound Frequency 500Hz, Frequency Modulation 50Hz - Vibrato ...
0
votes
0answers
65 views

extracting DC from audio signal for biasing

I've been wondering if there is a simple means of extracting a DC signal from an AC+DC signal for the purpose of providing a small DC supply to a CMOS device. Essentially the signal I'm considering ...
0
votes
1answer
78 views

Getting earphone out from music player

I've made an arduino based audio spectrum analyzer & it requires audio input from a music player/laptop/phone earphone out. I've tested this with earphone out from my audio player (Yamaha MCR-...
2
votes
1answer
88 views

How to calculate impedance for reverb tank in a guitar amp

Background: I'm in the process of restoring a HIWATT HI-GAIN 50 COMBO Valve guitar amp and one of the issues it has is that the reverb dial has no effect on the sound. Attempted troubleshooting: ...
0
votes
1answer
49 views

Bad background noise in audio capture [closed]

I have a microphone attached to a Realtek ALC5640. The circuitry is as below: L9 is Murata BLM15PD121SN1D The noise capture is here. How could I improve the situation and reduce this noise, if ...
0
votes
0answers
20 views

Connecting audio interface (balanced TRS jack line out) with synthesizer (TS jack line in) [duplicate]

I want to send signal (my vocal) from my audio interface to my korg minilogue synthesizer. The output of my audio interface is balanced TRS jack line out while the synthesizer wants unbalanced TS jack ...
3
votes
5answers
1k views

In the case of audio, would it be accurate to think of a potentiometer as a fader between two inputs?

I kinda already asked the question in title, but I will reiterate — In the case of audio, would it be accurate to think of a potentiometer with, for example, three lugs, as a fader between two inputs?...
12
votes
3answers
2k views

Audio Amplifier Op amp

I'm trying to design a circuit in which a microcontroller produces a signal and then using an amplifier drives an 8ohm speaker. I've so far used LM386, but it cannot go above 1W, which turned out to ...
0
votes
2answers
550 views

Beginning Audio Electronics [duplicate]

I'm 16 and interested in getting into audio electronics so I can make things like mixers and speakers, etc. I currently only have a rudimentary understanding of electrical circuits which extends only ...
5
votes
3answers
2k views

Death of Zen (Audio Amplifier) Questions

I am wanting to build the Death of Zen class A audio amp from Elliott Sound Products. Here is the circuit. I have a few questions: For all of the capacitors, what should the voltage rating be? I don'...
2
votes
1answer
747 views

Combining speaker outputs to one secondary amplifier

Background I have a Denon 5.1 av receiver and have bought some new speakers. The only restriction (from my wife) was on size so I have managed to get hold of a set of speakers for the Sony DAV-IS10 (...
3
votes
4answers
3k views

conversion of single ended audio input to differential

I am working on a bluetooth module for streaming audio signals. Audio signals coming from audio jacks are single ended,but datasheet of module has mentioned that differential audio signals are ...
5
votes
1answer
3k views

VCA Using JFET and Op Amp

Just messing around with LTSpice I came up with this VCA that simulates shockingly good for what it is: I don't recall ever seeing the use of an op amp to mix the signal and control voltage in an ...
1
vote
2answers
496 views

Bidirectional Digital Communication over Audio Signal? [closed]

I am trying to figure out a way to achieve low speed digital communication over an audio line. I have two devices that are connected with a two wire audio cable. Audio and Ground. From my research, I ...
4
votes
3answers
1k views

Audio Grade Capacitors - Marketing Hype or Better Technology

I have been reading a lot about audio grade capacitors lately, and I cannot find very good information about them. I have read many posts from different sites saying that audio grade capacitors are ...
10
votes
3answers
9k views

How can one pair of headphones be connected to two audio sources?

I'd like to connect one pair of headphones to the headphone jack on two audio sources simultaneously. I realize I can't just wire two audio sources in parallel since they'll then be driving each other....
5
votes
4answers
12k views

How to detect line level audio signal?

I'm planning to build an automatic switch box for line inputs to my speakers. The switching itself seems fairly straightforward (a pair of de/multiplexers), but I don't know how to detect the audio ...
0
votes
3answers
925 views

TDA7262 Audio Amplfier's SVR/MUTING pin (pin3)

What exactly is the SVR/MUTING pin on the TDA7262? I've done my research on it but I cant find much. I found something that said its to eliminate the thump the speaker gives off when power is applied ...
0
votes
1answer
35 views

Detecting signal / amplitude from 2 wire DC speaker

I want to create a circuit that replaces a 2 wire speaker in an existing electronic device. I want the device to be able to trigger an output when the amplitude of the signal that would regularly ...
2
votes
1answer
227 views

Wattage Rating for these Zeners

I have a circuit (Death of Zen audio amp) , which requires 2 12 volt zener diodes. What is a safe wattage rating for them? Does this work?
37
votes
6answers
37k views

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 ...
2
votes
3answers
8k views

DIY simple line out converter for “floating ground” car head unit?

On a 25W max power (10V p2p @ 4ohms) balanced (push-pull) high level output factory car audio head unit from which I need to feed a mono amplifier (for subwoofer) that only has an unbalanced line ...
1
vote
3answers
14k views

Reducing noise in an audio amplifer using opamp

I am trying to make an audio amplfier using an opamp for a project. It works kind of okay but the only issue is there seems to be a lot of noise in the output of a 0.5 watt speaker. I have tried ...
3
votes
2answers
2k views

Can one end of a transformer be used as a choke?

I want to build the "Death of Zen" audio amplifier and I found a video on YouTube of someone who built it and used a 10 mH choke for smoothing of the pulsating DC. I found an old transformer from an ...
4
votes
2answers
911 views

Noise detection data logger - wireless

I'm looking for some advice on which components to use for this application. The problem: We'd like to measure the amount of "noise" in a warehouse and display this on a LCD/monitor/whatever. When ...
0
votes
2answers
113 views

Op-amp circuit to control gain of two analog channels with one single-section potentiometer

I'm working on designing my own headphone amplifier with extremely high fidelity. One thing I want to incorporate is a circuit to control the gains of the two channel's using one single-channel ...
0
votes
1answer
494 views

Why is the cut summed in a graphic equalizer?

I would think a basic graphic equalizer could function as such: a bank of filters, each with their own connection through a potentiometer to a summer (such as an op-amp summer). However, I've run ...
12
votes
2answers
22k views

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 ...
0
votes
2answers
69 views

Will covering ring on male 1/4 TRS jack with tape work? [closed]

I plan to connect balanced TRS output with unbalanced TS input and I wonder if instead of cutting the cable and leaving ring floating I could just cover the male jack itself (the ring part that goes ...
-1
votes
2answers
783 views

What is the easiest way to filter engine and wind noise while keeping useful frequencies and speech? [closed]

I have a noisy car. The engine is not a real issue, the wind noise increases quickly with speed, even at allowed highway speed. I have some around-ear headphones with good sound insulation but I don'...
22
votes
6answers
7k views

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 ...
4
votes
1answer
89 views

(Electret Microphone) Why is input taken from the capacitor?

Why is the input signal taken from the -ve side of the capacitor? I do understand that the resistor has been added for voltage divider. Is this actually for filtering purposes? Or is the capacitor ...
8
votes
3answers
1k views

Why is the collector feedback bias popular in electret-mic preamp circuits?

I got some simple electret microphone modules and I've been experimenting with audio amplifiers. I googled to find some example circuits, and I found that most of them resemble the circuit above. I ...
0
votes
1answer
72 views

How many Watts is my stereo? [closed]

I have a Pioneer SX-316-S stereo. It has six speakers. The specification says it consumes 320 Watts. It also says the continuous power output is 100W per channel. It also says the RMS power output is ...
4
votes
1answer
1k views

Why would I need AC coupling if audio inputs already do the job?

I'm transmitting data from a microcontroller to a smarphone mic input and I was suggested to use this circuit to adapt the 5v digital signal: Taken from this tutorial The way I see it R2 and R3 ...
4
votes
2answers
668 views

Analog switch with a fixed state when not powered?

I am looking for a chip that could handle DPDT (or SPDT, or ultimately SPST) analog switch for audio routing (in the mOhm range resistance) and can guarantee one state when there is no power supply. ...
1
vote
2answers
65 views

How can I determine the cause of parasitic oscillation in a Teac A-R630 preamp stage?

The amp exhibits intermittent crackling noise, which I think is parasitic oscillation as it stops immediately I touch the base of Q409 with a scope probe or an insulated screwdriver. The amp will ...
2
votes
1answer
72 views

How (not) to leave class-D amplifier's input hanging

I would like to setup an audio solution for Raspberry Pi Zero that consists of a headphone jack and a speaker. The goal is that sounds will be played through an internal speaker, and when a headphone ...
6
votes
4answers
5k views

Formula for Logarithmic (audio taper) pot

What I would like I am trying to determine the formula for an audio taper (logarithmic) pot. I would like a formula that takes R and P as inputs. R being the total resistance and P being the "...
1
vote
0answers
59 views

2 Crossovers in parallel: how are frequencies distributed?

So, the other day I connected on parallel a dual-voice subwoofer-system (a Pyle XSUB1-150-4-12d crossover — like this one ... link might be unavailable after Aug 28, 2019 ... — and 2 individual ...
1
vote
1answer
312 views

Dolby HX PRO implementation on existing tape recording deck

I'm experimenting the implementation of Dolby HX PRO's IC into an old stereo Fostex tape deck to improve high frequency and headroom capabilities. HX PRO works as a dynamic processor with the BIAS ...
0
votes
0answers
146 views

Low-Pass Filter Selection and Placement in Active Noise Cancellation

This continues in the same vein as my previous question - I'm working on an Active Noise Cancellation circuit to get rid of highway noises in my bedroom. Based off an ANC circuit pictured below, I ...
0
votes
6answers
236 views

How do I set my speakers out of phase?

A little bit of context: I'm doing a project for my physics class where I could choose the topic, and I chose to do phases in sound and noise cancellation (wavelengths and frequencies). Essentially, ...
1
vote
1answer
292 views

Linkwitz-Riley “isolator” equaliser question

I don't understand one thing about 3 way EQ based on Linkwitz-Riley crossover. We split the signal to 3 bands - low, mid and high. Why is mid band phase inverted? It doesn't make sense to me, but ...
0
votes
1answer
135 views

Class A amplifier with preamp design

I am currently working on a class A audio amplifier designed to work with line in voltage (about -400mv to +400mv). I plan on using an IRFP240 for the mosfet but am undecided on the transistor stage. ...