Questions tagged [audio]

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

Filter by
Sorted by
Tagged with
0
votes
1answer
42 views

What for are two resistors and one capacitor when attaching an audio CD drive output to a TDA7318, but not for Line In?

I'm trying to build a TDA7318 audio mixer chip into my automobile infotainment system. Now I've found a similar project, where the output of the CD drive is attached to the chip by using two resistors ...
0
votes
1answer
120 views

audio jack ground to main earth ground, safe or not?

My audio amplifier got some unclear noise from ground. amplifier ground is connected to player, and use some decent RCA cables, also tried to add ground loop isolatior to RCA cables. None of them ...
4
votes
1answer
346 views

Bootstrap in power amplifier

So I know the theory behind a bootstrap current source in power audio amplifier and understand its operating principle but some things remain uncertain to me. First - how to divide the collector ...
0
votes
1answer
120 views

Will a potentiometer let me adjust the volume on an RCA to 3.5mm headphone cable?

I don't know a lot about EE, and this might not be the best place to ask, but I have a really basic question. I'm thinking about cutting an RCA to 3.5mm cable in half and inserting a pot for volume ...
0
votes
1answer
83 views

How to select resistor values for passive mixer

Total newbie question: I wanted to buy a passive audio mixer, and I wanted it to be cheap. I picked up one of these in a hurry, only to realise that it's a switch. But hey, it's cheap, so let's make ...
0
votes
1answer
168 views

How to make a two channel mono mixer with in balance control into stereo output

I thought I wanted a circuit that was a basic pan control, but after mapping it out it isn't so standard after all. The final design will have this exposed: two mono inputs (left and right), one ...
0
votes
1answer
1k views

Laser X 88016 remove beeping noise

I have bought a Laser X 88016 two player set gaming device. When turned, the device on makes an annoying beeping noise every three seconds, no matter what. (As you can imagine you can't really stealth ...
0
votes
0answers
105 views

Feedback on converting signal from 3.5mm jack to ADC on STM32 Bluepill

I'd like some feedback on my circuit. My goal is to convert an audio signal coming out of my laptop's 3.5mm jack (using a sin generator at max volume gives me about a ±1.5V wave) to digital using the ...
0
votes
1answer
49 views

5.1 audio switch without popping noises

I have two audio systems, one in my living room and one in my office. My sound system in the living room is a Teufel Concept E450 Digital which sadly isn't compatible with receivers (since it's a ...
0
votes
0answers
79 views

Understanding analog noise propagation

Background I am designing a low noise gain section for a power amplifier. This section consists of 2 parts: the input section, taking care of gain a single-ended to balanced buffer with unity gain (...
0
votes
2answers
921 views

How can I connect two audio channels (L+ L- and R+ R-) to a jack (L, R, GND)?

I am working on a "device" based on a CSR8645 Bluetooth Receiver module from eBay. . My current issue is the fact that each audio channel has its own ground, and if I connect both grounds ...
1
vote
0answers
49 views

Improving Stereo PCB Design

I just made my first attempt at making a Bluetooth Stereo PCB, and it was okay. This is a Class D Audio Amplifier, with the main IC being the TPA3122D2. O was planning on powering it through USB C, ...
0
votes
1answer
45 views

How could I create mixed audio, with a single PWM output?

Background: I recently made a project which emits pure tones on a speaker, and it got me thinking about how I was restricted to simple pitches. How would I simulate a chord if I can only play one ...
2
votes
3answers
133 views

Simple power amplifier with feedback - designing procedure

I have a problem with understanding the whole feedback business in BJT power amplifier. So far, I only considered it in terms of thermal stability and \$β\$ uncertainty in simple 1-staged amps and was ...
1
vote
0answers
61 views

How to build an audio mute button?

I'm planning on building a mute button that would physically cut the audio signal from or to my computer. This could be used for both input and output. I would like to be able to disconnect my ...
0
votes
1answer
74 views

Can someone explain what this op amp circuit achieves?

In this schematic a line-level audio signal is passed in to R42 and out of the op amp. Can someone explain the effect of the op amp on the signal in this configuration?
1
vote
3answers
515 views

How to reduce audio noise from Bluetooth module

I assembled a "Portable Bluetooth Speaker" with of the shelf Bluetooth/MP3 module and tiny stereo amplifier (supposedly 10W per channel) plus battery pack. Both devices need 12 volt. When ...
0
votes
1answer
55 views

Why are the two channels of my subwoofer connected by a resistor?

I bought a new amplifier module for my subwoofer and recognized that the two LFE channel inputs are directly connected on the circuit board via a resistor. I assembled the subwoofer meanwhile and I ...
2
votes
2answers
194 views

VU meter noises entering the master output

I'm currently working on a very simple mixing table, and everything works fine except that when I connect the VU meter (using a Y splitter from the master output, one end going to the audio output ...
1
vote
1answer
133 views

TL072 opamp clipping problem

I'm trying to drive a TPA6120 headphone amplifier with TL072. I use single 24VDC supply with a TLE2426 virtual ground. The TL072 works well and puts out around 21Vp-p sine wave. But as soon as I ...
0
votes
1answer
92 views

Using a computer mic with lm386

I'm working on a two way amplifier/intercom for my parents to use in the car because of road noise and hearing problems. I got a couple LM386n-4 and I've tried the circuit layout from here: http://www....
0
votes
1answer
131 views

Variable band-pass filter for splitting audio signal into separate signals (high and low freqs)

I've been wondering for quite some time how to create a sort of audio splitter. The idea is to get an audio signal (e.g. guitar) at the input, and have two separate outputs, one with the input's low ...
0
votes
1answer
148 views

The purpose of capacitors C1, C2 and C3 in this audio amplifier

I am trying to analyse this amplifier circuit and I can not understand what the purpose of the 3 capacitors C1, C2 and C3 are if anyone could explain that would be much appreciated. Thanks in advance.
0
votes
1answer
364 views

Rectifier unit in Neve 33609 Compressor Schematic

Real quick question, I'm analyzing the Neve 33609 schematic (as shown below), and I can't figure out what is responsible for rectifying the AC audio signal into a DC control voltage. If anyone has an ...
0
votes
0answers
22 views

IEC60950: cable distribution network definition

The definition of a cable distribution network is given in IEC60950: "mainly intended for transmission of video and/or audio signals between separate buildings or between outdoor antennas and ...
0
votes
1answer
45 views

Does a BMS reduce the quality of the output of batteries?

I plan to build a high quality headphone amplifier. It does not use much power (<1A) so I think about using 18650 batteries as power supply. I am pretty sure these batteries should be a very smooth ...
0
votes
1answer
39 views

Reading audio transformer datasheet

I'm using an audio transformer SP-70 to isolate audio. (http://catalog.triadmagnetics.com/Asset/SP-70.pdf) The question arises what is the maximum AC current allowed to operate the transformer without ...
1
vote
0answers
179 views

Very long distance analog audio transmission over cable

Summary: I want to transmit an audio signal (300Hz-3kHz) without modulation over a 10 km cable. I don't know how to. I have looked for a similar post and couldn't find any I hope I am not creating a ...
0
votes
1answer
56 views

Weird fault in circuit - Charge building up and blocking potentiometer?

I've made some inline headphone volume attenuators myself for live use, so that we have some volume control on our hip and don't have to wander over to the headphone amp, partly because I didn't want ...
0
votes
1answer
30 views

How do I wire a trs jack to a dual channel amplifier?

So I have a bluetooth audio amp circuit board. I believe it is dual channel it has two chips (one for left, one for right) The outputs are R+ R- L+ L-, but I want to wire them to a trs jack, which has ...
1
vote
1answer
84 views

Audio Circuit Playback

I have an audio circuit setup currently in which a microcontroller (PIC32MM) sends PWM signals to an amplifier which is attached to some speakers in order to hear what is going on. I have attached a ...
0
votes
0answers
82 views

Why is my LTspice simulation taking so long? [duplicate]

I'm simulating an audio amplifier circuit in LTspice, using an opamp and 555 timer, based on the circuit I found here. This is the circuit diagram and output: As seen below, the transient analysis is ...
0
votes
1answer
256 views

Need help with weird audio wire colors

I would like to replace my broken earphone's 3.5mm audio jack. However, I am not able to indicate which wire is the right (red) and which is the left (green). I see the red and green wires but they ...
0
votes
2answers
109 views

Amplifying a minuscule signal without external power source?

I recently came across this circuit : http://sgitornado.altervista.org/diyirig.html I tried to understand it, but I have several questions I can't really search for, as I'm an amateur and don't know ...
0
votes
2answers
226 views

How to remove the high pitched noise at the output of my audio amplifier circuit?

I'm trying to simulate an audio amplifier circuit in LTspice. I made this circuit based on the circuit I found here: https://circuits-diy.com/how-to-make-audio-amplifier-circuit-using-555-timer/ . I'm ...
1
vote
1answer
49 views

Does the signal direction matter for a series N-channel FET switch circuit?

I'm working with a 40-year old audio circuit that someone modified to use an FET as a series switch. The circuit uses the Toshiba 2SK30A N-channel FET to pass a nominal ±1 VAC audio signal. The Source-...
1
vote
0answers
44 views

Building a “if” statement circuit where i can control different light diodes

I want to design a circuit to react in different ways depending if a microphone picks up one frequency and in different way if it picks up the some other frequency. I want different lights to shine ...
0
votes
0answers
33 views

Automatic Headphone Control Issues

A friend wants an automatic headphone controller for his bike. According to the Android spec we should be able to add a bias resistor of 5kohm between mic and ground, short mic to ground for play/...
0
votes
1answer
50 views

Somehow the DSP library is combining a stereo channel to a mono one, any ideas?

I have a confusing problem that's happening to me, ill explain it to the best of my abilities with code, text, all that good stuff. THE PROBLEM: I have a laptop that uses its in-line output into an ...
1
vote
3answers
117 views

Grounding a chassis with two prong plug

So I kinda shot myself in the foot by purchasing a two prong wall wart to power an audio preamplifier that I designed. I forgot to consider the fact that I should ground my chassis to the earth ...
0
votes
1answer
108 views

Is it okay to have a ground plane with a Class D Amplifier?

I'm working on building a Class D Amplifier (TPA3122), and from what I understand, you want to connect the grounds of the amplifier using a star connection. On this circuit, I plan on using a DC-DC ...
0
votes
0answers
119 views

Use stereo DAC for mono application

I am developing an audio device that will have a mono audio output. I currently use the PCM5102A stereo DAC in my prototype as it is easy to find as a separate module. But it does have a stereo output,...
1
vote
1answer
61 views

Single NPN Emitter-Follower in amplifier's input stage

I am currently examining the "El Cheapo" amplifier and despite its apparent obviousness I'm still not sure about NPN/PNP interchangeability. Is there any particular reason why there is PNP ...
1
vote
3answers
165 views

Noisy AES audio signal in studio installation

This is a question about digital audio cables. I know this isn't an audio engineering forum but the question's specific to the physical connections and there's limited info online which I can find ...
2
votes
0answers
128 views

Overtones(?) seem to be showing up in FFT of audio signal

I am processing audio data using a Teensy 3.2. I have a microphone attached to it, and am playing music in my room using some powerful speakers. When I look at data from the Fourier Transform of the ...
1
vote
2answers
195 views

Bucketing FFT into one-third octave bands

I'm trying to understand how to take the results of an FFT calculation and bin them to one-third octave bands. As my questions aren't about the code but about fundamentally understanding the arguments ...
0
votes
1answer
304 views

Interfacing the ESP32 A2DP Sink via I2S with the STM32

hope y'all are well and safe. I am back again! Woooo! Problem: The sound produced is really glitchy and the audio can be barley made. Setup: I have an ESP32 using the A2DP profile as a BT sink to ...
4
votes
1answer
172 views

LM393 comparator misbehaving and causing issues

I've been stuck on (what seems to be) a very unusual issue with a little audio circuit I’m designing. I wonder if anyone here can quickly highlight the flaws of my design and/or offer an insight into ...
0
votes
1answer
65 views

Problem in microphone circuit

I've placed the circuit on the breadboard and found an unexpected low-frequency noise appearing again and again. The computer microphone doesn't show this type of distortion. But my circuit is showing....
0
votes
2answers
279 views

i want to know if the potentiometer is broken or just dirty and if it's broken can i find the same in the market? [closed]

Hi i have speakers labtec arena 530 . i opened the main speaker and the problem is from the potentiometer I can make a brigde and connect 2 pot of the potentiometer sound become clean but i loose the ...

1
3 4
5
6 7
54