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

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2
votes
2answers
324 views

Detect 3.5mm stereo jack plugged in

First off i'm using arduino as MCU. I have two internal speakers inside a box to output the sound from a FM Rádio Module, but i have also an stereo jack in my box, so anyone can plug a external ...
1
vote
2answers
106 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 ...
0
votes
2answers
32 views

Combining 1, 2 or 3 audio signals so the output always has the same amplitude. LM3900

So I am outputting up to 3, 0-5V signals from three separate DACs. The issue I have come into is that I would like to combine all three signals to form a single output of the same amplitude. Currently ...
2
votes
0answers
39 views

Why are five pin XLRs used for long MONO audio connections?

I understand why a 3 pin XLR would be used for a balanced single, so what are the additional pins for. I have read someone that is has to do with capacitance on long cables. (These days a digital ...
0
votes
0answers
28 views

Guidance designing low-pass filter for audio circuit power supply

I'm developing a BeagleBone Black cape that has, among other things, and audio CODEC and 10 W amplifier. The “other things” include a connection to WS2812 LEDs, which generate a lot of PWM switching ...
-2
votes
0answers
37 views

Are there ready-made boards with DSP targeted to active noise cancellation? [on hold]

I would like to play with active noise cancellation but I don't know what tools to use to begin with. My application would be simple ducts, or low-frequency and narrowband noise (compressors, for ...
0
votes
3answers
60 views

sd mp3 player board *Christmas Present Project* [on hold]

I recently bought a turtle night light that projects starts and plays a little lullaby. the music is triggered by a switch but i would like to have it so on click of the switch it plays music i have ...
0
votes
1answer
53 views

Is it possible to use a dual rail power system to power op-amp which is designed for a single supply?

I am designing an amplifier circuit using the LM386 amplifier. I am using the schematic below as a guide. I have access to 3 pins: +5V, virtualGND and -5V. Is it possible to power this amplifier using ...
0
votes
1answer
52 views

Strange frequency of audio output voltage

For a school science experiment, we have stripped an audio cable and hooked the right channel and ground wires up to a voltage graphing device. The audio cable is plugged into the audio output of our ...
0
votes
1answer
25 views

Volume control with DS1807 digital potentiometer?

I'm making a digital synth for a project and I need to wire in an Arduino-controlled volume circuit. Right now I'm outputting a 0-5V audio signal and cutting it down to a pure AC 0.5V signal with a ...
0
votes
0answers
30 views

How to choose output network RC and RL values of an audio amplifier?

With "output network" I'm referring to that RC series circuit connected from the amplifier output to the ground, and the following RL parallel circuit connected in series with the output. I know what ...
-2
votes
1answer
59 views

DIY HiFi System components [closed]

I'd like to create small HiFi home system with few requirements: It should use ONLY HDD of up to 100 GB (No CDs, Radio or other crap!) With remote control With small screen/monitor for easy visual ...
0
votes
0answers
16 views

What kind of setup and components are in this and how does it work. Also, where can go and find the parts to buy? [duplicate]

This is a sound system I am trying to recreate. It has a 5v fm/bluetooth module on the top of it with a switch to turn on and off.It then runs to a Ceiling speaker with some sort of motherboard in it ...
1
vote
2answers
93 views

Audio amplifier controlling volume with Arduino?

I'm building a project that outputs audio via an Arduino to a powered computer speaker. This audio signal comes from a sine-wave-table lookup that I step through at various frequencies, setting a PWM ...
1
vote
2answers
37 views

How do I connect 3 audio inputs with a switch?

I have 3 outputs from different audio sources via aux cable. I'm trying to combine them all into a box and have an easy way to change the audio source. If only one source is going to be used at a time ...
0
votes
4answers
79 views

Using frequency to turn a circuit on

I would like to run 3 circuits and turn them on based on a frequency input from an audio source. I would like to turn on a circuit at a mosfet gate for example with tone A at 100Hz tone, B with 1kHz, ...
1
vote
1answer
94 views

Handling audio signals on a 5v ADC

Some days ago I have made a multiplexed 3x8 LED grid based on Arduino RGB Controller. In my case I don't use RGB but row1, row2 and row3. While I already made some nice animations but I'm not really ...
0
votes
1answer
47 views

Speaker and Headphones on Microcomputer

I am designing a circuit for the CHIP Microcomputer and I want to enable audio output using headphones OR a speaker. For clarification, when the user plugs in headphones, I want the speakers to be ...
-3
votes
0answers
72 views

How Transistor works as an amplifier in this circuit?

I want to build a circuit to use transistor as an amplifier. I searched on google and found this circuit which uses transistor to amplify the audio. Is it only the transistor or any IC which is doing ...
0
votes
0answers
48 views

How bootsrap capacitor work in a power amplifier?

The foremost reason why a bootstrap capacitor is used in a power amplifier is to increase the output voltage swing to the power supply. Theres a relationship between resistor R4 and output voltage: ...
0
votes
1answer
58 views

Audio Spectrum Analysis without uC

I have to design a spectrum analyzer that takes a normal audio input and creates a 4 band spectrum display. My current plan to accomplish this task is to construct 4 band pass filters centered around ...
0
votes
1answer
40 views

Operation of this power amplifier

My query is that..At node B the voltage is 11.7 V ..and at node A it is 11V according to text, but it should be two diode drop below the voltage at node B i.e it should be 10.3 V(because 0.7V voltage ...
0
votes
1answer
48 views

Headphones with dual jack, reduced volume

I recently built a pair of headphones and added an audio jack input to both the cans, for convenience of connecting. That would also serve another purpose of letting my girlfriend hear the same music ...
0
votes
0answers
33 views

Audio Speaker Component

I am trying to create a product unit with an enclosed microcontroller that can function like a WiFi-enabled bulb (albeit with an entire enclosure and an enclosed audio speaker). I am a total beginner ...
1
vote
1answer
81 views

7W IC amplifier

I have a 7W Audio Amplifier IC Module. It's instruction says power input should be 12~16 Volts. The audio source should be connected to "IN" and "G". Output should be a 7W Speaker to "SPK". In lab, ...
0
votes
1answer
22 views

Raspi Audio Problems When Using a Servo

So I am trying to make a raspberry pi control a servo but it also needs to have speakers attached. But whenever the servo is powered there is a horrible audio output through the speakers. This will ...
1
vote
2answers
33 views

Piezo contact mic into iMac - avoid signal spikes

I've wired an external piezo as contact mic to the TRRS 3.5 jack of an iMac and it is working fine - BUT the signal will just randomly stop after hitting the contact mic several times too hard, so I ...
0
votes
0answers
30 views

active stereo summing [duplicate]

i need to combine two stereo line level inputs into a single headphone output. i'm taking piano lessons so i need to combine the output of my piano (stereo line level afaik) and the output of my ...
0
votes
0answers
13 views

LPC4337 I2S Synchronized Word Select Signals

I am trying to setup the I2S peripheral on an LPC4337 device so that it will send and receive audio data in master mode. The problem I am having is that I would like to ensure that both the transmit ...
-1
votes
2answers
52 views

I need to sample 8 audio sources at audio quality, what MCU can I use? [closed]

I need to sample 8 audio sources at the same time, at a decent frequency (say, 40Khz). Being only familiar with Arduino, I searched online for tutorials and articles about using interfacing it with ...
0
votes
1answer
37 views

Multiple audio codecs on an i.MX6Q

We are currently trying to bring up a custom i.MX6Q based board with Linux 3.10.17, two TI TLV320AIC3106 codecs and an S/PDIF interface. The two codecs are I2S slaves and are connected to the i.MX6 ...
1
vote
2answers
78 views

Which capacitor for DC blocking in audio applications?

Which capacitor (electrolytic, film, ceramic) do you use for DC blocking in audio applications? From what I have seen most people use electrolytic capacitors. But, also from power decoupling theory ...
0
votes
1answer
43 views

DC Thump-like noise with Isolation Transformer [closed]

I put an isolation transformer inline with my audio (unbalanced 2 channel audio; with L, R, signal Ground). It still makes noise when plugging the auxiliary cord in (kind of like 2 thumping noises) ...
0
votes
1answer
34 views

3.5mm Stereo output to 3.5mm mic input crossover

I have two devices, each with two 3.5mm jacks for the usual audio out / in. I need a way to cross-over between the two, such that the stereo output of one, goes to the mic input of the other. I have ...
-1
votes
1answer
102 views

Audio Transmission using LED

Referring to the attached schematic. The optical system setup is to transfer audio using LED. At the receiver end I failed to sense any audio signal. I have checked both LEDs using oscilloscope and ...
-3
votes
1answer
69 views

LM386 with power bank [closed]

I made a guitar amp using the LM386 and i power it with a power bank and a sparkfun usb breakout board but the power bank shuts down by itself after 20-30 seconds. I read it's because the circuit ...
0
votes
0answers
24 views

Dynamic Microphone with XLR Phantom power

I designed this schematic after viewing the typical phantom power supply circuit. But i am still not sure that the dynamic microphone will work or not. Please take a look and tell me. I just ...
-1
votes
1answer
111 views

Can I connect multiple speaker boxes to a single amplifier output? [closed]

I've seen arrays of passive speaker boxes (high output passive professional PA speakers) that were connected to each other and only the last (or first) one was connected to the power amplifier (a very ...
0
votes
1answer
75 views

microphone to a microcontroller. very simple

I want to take a microphone and send it to a micro controller. I then want that microcontroller to evaluate if the audio is above a set db reading and then send a yes or no single to turn on a light. ...
1
vote
1answer
66 views

Can I run my audio mixer off the battery powering my amplifier?

Background info: I have a small battery powered 25W amplifier/speaker combo. KustomSound CB25X, with two 6V 4.5Ah SLA batteries wired in series for 12V. Fully charged, the voltage seems to be close ...
1
vote
2answers
74 views

Simulating triodes in LTSpice, Long tail pair phase splitter

I am attempting to simulate a long tail pair phase splitter using two 12AX7 triodes in LTSpice. I tried multiple subcircuit models for the triode, all yielding the same results. I want to know if the ...
0
votes
0answers
47 views

Connecting a piezo/contact-mic to an iMac

I want to catch vibrations using a contact-mic made from a piezo element so I can measure vibration as loudness in OSX (Yosemite, iMac 14,2). But when I connect it to the iMac's 3.5 jack it ...
-4
votes
1answer
42 views

Audiotechnica headphones [closed]

Hi i recently brought a pair of Audio-Technica ATH-M50. I really surprised that when i connect them to my smartphone or the mp3. The volume base on these pair headphones is very low, even if i ...
0
votes
0answers
21 views

WM8904 sound card input voltage problem

I have an evaluation board(AT91SAM9N12-EK) running linux with WM8904 sound card. With normal input on its line in, I cannot hear anything. Like I plug my Laptop or Smartphone's line out into the ...
3
votes
1answer
64 views

Switching Supply Noise Filter for Audio Circuit

I want to make an external power supply for various pieces of "vintage" audio gear that run on +-18V, +48V, -9V and so on. So the plan is to put several off-the-shelf AC/DC switchers (like Meanwell ...
0
votes
1answer
85 views

Which is the loudest in terms of sound intensity - Sine, Square or Sawtooth waveform?

From this, (Square wave / Sine wave is more audible) I now understand that a Square soundwave will be louder than that of a Sine sound wave when played at the same frequency (for example 500 Hz). ...
2
votes
2answers
269 views

Is there an audio amplifier chip or circuit that amplifies certain amplitudes in a signal less or more than other amplitudes?

Like for instance, that would amplify on an exponential curve where the lower amplitudes get the maximum amplification and the highest amplitudes would get no amplification? Is there an analog chip ...
2
votes
2answers
121 views

Is it feasible to synthesise sound with analog circuitry these days?

A friend of mine who is a layman in terms of electronics asked me to teach him how to synthesise audio with some analog circuit and how to build it. For some reason it has to be analog. Probably ...
0
votes
0answers
36 views

How Impedance at Frequencies affect Audio

I am trying to build an isolation transformer for my unbalanced 2 channel audio signal. How is Audio signal affected by different impedance's (of the transformer) over a frequency range? where: ...
0
votes
1answer
57 views

DC 5V to Audio Line Level

Firstly, I'm a hobbyist and have a lot to learn. I'm trying to get a 0-5V signal created by a microcontroller to +/-2V audio level. I don't want to spend a lot and would like to keep the part count ...