Questions tagged [audio]
Questions about designing electronics for measuring, processing, and amplifying audio signals.
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HDMI output from FPGA
I've got an old project that produces NTSC video output from an FPGA using a resistor ladder DAC. It also produces a stereo audio signal using a similar RL DAC.
I'd like to bring it into the modern ...
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RF signal on Audio/Music/Guitar equipment
It is looking like the standard RF noise from my (new to me) old apartment wiring through my amp to my speakers. Suspected it could be due to poor guitar shielding/grounding, bad cables etc. Started ...
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Eliminating Noise from Audio Amp Board Input
I made this project by shajeeb (linked below), and I am having trouble with noisy ground lines. The circuit I made is the same as the diagram below except for where I connect the speaker and amplifier ...
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Why am I not getting an output from this breadboarded phaser?
After following along with a hobbyist's video, I breadboarded a phaser. Unfortunately it seems my circuit is not achieving anything close to what the hobbyist achieved with his.
I believe the issue is ...
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4
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How can I remove DC from an audio signal?
I am trying to "isolate" an audio signal that is transmitted on top of a 24V (DC) power supply voltage.
This construct is used in door intercom systems from TCS.
The audio signal is the ...
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Connecting an input and output to my Bluetooth headphones [closed]
I would like to connect my desk phone to my Bluetooth earbuds. I can unplug the cable from the handset of the desk phone and I can find a one way Bluetooth connector so I could listen to the output ...
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Capture audio from TCS Intercom BUS
I try to monitor and capture audio on a TCS Intercom.
There a several projects out there who have revers engineered the bus protocol.
I got it working to see activity on the bus when someone rings the ...
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Confused about how to wire headphone jack with a schematic
I've been trying to make an LED driver that responds to a signal sent over an audio cable and found this schematic:
I'm pretty sure that the middle ring on the jack and socket (third contact) is the ...
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Is there any problems with this baxandall tone control circuit ? Can you guys review it? [closed]
Can you guys review this circuit and tell me if there is something I am doing. As this is my first time?
I have a vague idea of impedance. Can you guys check that too. Share any good resources to ...
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Noise issue when powering several audio devices from the same power source
I'm working on my portable music production setup and I'm having noise issues due to connecting all my gear to the same power source.
I have three devices (a sampler, a keyboard/synthesizer and a ...
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Arduino's impedance in breadboard circuit
(Warning, as this is a long question, asked by students that don't know what they're doing. Perhaps our questions are too general and can't be answered but at this point we'll take all the help we can ...
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Laser communication system to transmit Audio
The audio in these two circuits is only transmitted when they are both connected to the same battery (Vcc), and only the laser control audio level not the transmitting process.
When I connect the ...
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Identifying this coax connector?
Circular 1-pin coax connector. Trying to identify so I can buy a new socket for it.
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Unity Gain Buffer Output Impedance
First time here. I'm not an engineer so please pardon my lack of technical expertise. Thanks in advance for your help!
Here's is the circuit in question:
I've been told that R5 (10K) sets the ...
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Do we need to guard the input traces of an audio power amplifier?
This is a continuation of this question. I am using an LM4670SD/NOPB in my design. The IC has a 5 V supply.
The input of the power amplifier (+IN & -IN) comes from a smart module from Quectel.
...
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Audio Power Amplifier Layout clarifications
I am using LM4670SD/NOPB in my design. The IC is working at 5 V supply.
This IC requires an 8 Ω speaker.
My first question is,
In that case do the lines Vo1 and Vo2 needs a differential impedance of ...
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Impedance matching: headphones out / hijacked op-amp pin -> guitar input
I have a Vox "amplug" pocket amp which has a female 1/4" mono input, it's supposed to be dangling directly from the guitar's output jack, and has 3.5mm TRS headphones out. I'd like to ...
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Real-Time Audio Processing
this is my first post on here so I hope I am in the right directory to ask this or if there's another channel I should sent this in, let me know.
Basically, what I am trying to do is use a sound ...
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Inrush current limiter thermistor acting up
One of the power amps I am working on uses a thermistor for inrush current limiting (SL15 25003) as shown in the schematic below (ICL1). When I was testing the unit it seemed to me that there was some ...
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Sharing ground between circuit and audio input?
I'm trying to build a VU meter circuit, and followed this guide/diagram (link)
I understand how the circuit should work in theory (mainly the OP-amps and the "logic"), except for the ground ...
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Hum without ground loop
I have an audio measurement system. The system is connected to and powered by a laptop. The system has no other connection to the AC grid. Now, if the laptop is connected to the AC grid and i measure ...
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Split and mix audio signals
I need to feed input to an audio amplifier from an USB DAC. The audio amplifier has separated inputs for headphone and speaker but DAC has only one output (stereo). Moreover the speaker input is mono ...
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Line-out vs headphone-out impedance
I'm thinking about the example of two output jacks on the back of a computer, one for line out and one for headphones. I understand that the line out in generally an "unamplified" signal and ...
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Is it possible to add headphones to a Geiger counter circuit?
The main problem is as follows. From what it seems, most Geiger counter circuits opt for a piezo clicker. I'd like to just plug in a 3.5mm audio jack and be able to hear when pulses come in. The ...
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Amplifier chassis noise when not earth grounded
I build a kind of audio amplifier (it's actually a mixer). The problem is that the output gives a high frequency pitch noisy sound as soon as I touch the front panel which is part of the chassis. It ...
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What might be killing the output to my amp, with every modification I try to make to my audio circuit?
I’ve been working on an audio project connected to a unique Stylophone-type keyboard (that I designed), using a 555 timer for the main circuit. I built a really cool box with 5 little powered outlets ...
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Calculating audio sample output rate for synthesizer
I'm building a synthesizer on an FPGA and I'm having trouble calculating sampling rates. Currently, I'm running a system clock at 98.3 MHz and I want to produce 16-bit audio at the output.
I've got a ...
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60
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Maximum voltage/current on a passive 8 ohm buzzer
I have a buzzer with:
8 ohm
1 watt rated power
Resonant frequency: 700/600 Hz
In order to make it sound, should I apply a PWM with 700/600 Hz, and turning ON and OFF?
What is the maximum voltage? ...
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answer
83
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Random noise in speaker with ESP32+DAC+Amplifier
We are facing the following issue with our application board based off ESP32 module.
We are using PCM5102 from TI as a DAC running over a I2S interface. The DAC is connected to the TPA3136 amplifier ...
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Audio Amplifier Transistor with Diodes
I'm trying to understand this audio amplifier.
Whats the purpose of these transistors with the diodes in series?
The circuit i'm trying to understand is from the NAD-S300
https://audiophillness.com/wp-...
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Drawbacks of Class A push pull audio power amplifier?
I am willing to develop an Audio power Amplifier myself in a Push Pull configuration of two complementary transistors (NPN,PNP).
On the internet, it is found that most of the conventional Class AB ...
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What is SAI frame synchro?
The SAI interface, as used by ST and others, includes some options which I have not been able to find any explanation of. Justme's answer provides a great explanation of frame, slot, and data size; I'...
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Grounding in a balanced audio (XLR/Sub-D) switch?
I am currently working on a switch for XLR/Sub-D connections. However I am unsure as to how I have to handle grounding. Do I have to switch the ground for each channel or can they be bundled together?
...
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Can I capture audio over SPI on from the onboard MEMS microphone?
I have a STM32H735G-DK Discovery board and would like to record audio from the onboard digital MEMS microphone, a MP34DT01TR-M which provides PDM audio.
It would seem to me the simplest way to do ...
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Should I use transformer + op-amp or only op-amp to amplify small audio signal?
I am trying to amplify a 10uV audio signal. This is easy enough with an op-amp, except that I need to make sure Vos is much smaller than the signal. 10uV is doable, but if I want to amplify much ...
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Can I Use a MOSFET In Series With My Speaker?
I'm normally a software guy, so please bear with me :-)
I have a TDA2030A amplifier board like this one that I'm using to play audio through a small speaker. I have a microcontroller which I want to ...
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Voltage amplifier stage in Douglas Self's parallel op-amp audio amplifier
I'm looking at making Douglas Self's parallel op-amp audio amplifier (link), and there's a few things I don't understand in the voltage amplifier stage (schematic below). He says the 22.7 dB ...
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circuit for phototransistor sound receiver
I'd like to build a phototransistor receiver. I've tried different sample circuits (I'm not any good in circuit design) and would like to ask for assistance. I am looking for a circuit that is capable ...
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Should an unused audio input be left floating or connected to GND?
I am designing an audio circuit with multiple signal inputs through a jack connector that may not always be active simultaneously. In this case, is it better to connect them to GND when not in use to ...
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Further Electronic aspects of iPhone audio recording via lightning connector
Following on from this post I wired up a way to record audio on an iphone (the important design points quoted here):
The iPhone as well as other mobiles will apply a DC voltage about 1.5-2.5V to the ...
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Grounded ADC pins on the CS4272-CZZR producing horrible noise?
I am currently busy with an audio processing project that requires 4 output channels. I have a Nucleo F303RE running some digital filtering on audio data, which is being read by one of the two CS4272s ...
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Something about the impedances of charge amplifiers
it is my understanding that due to the effect of virtual grounding, the input impedance of a charge amplifier is basically zero. If that's the case, then is there any reason to even worry about the ...
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LM386 Amplifier Mix Dual Audio Signals
I am trying to build an audio amplifier which will get input from an electret microphone and music signals from mobile using aux cable. I found a schematic diagram in the Circuit Digest website which ...
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How to detect jack insertion in a 3.5mm socket
I'm designing a custom PCB for a hobby project that includes a 3.5mm jack connector (PJ-3420, schematics below) which receives audio from a DAC (PCM5102). I'd like a way to detect that a jack has been ...
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Speaker/headphone amplifier switch feature triggered by 'switch' jack
I'm planning to use an amplifier that has both (distinct) speakers and headphones outputs and an input to select between them.
Such input switch the amplifier output on headphones if logic level is ...
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Where should the audio-input be available in this RF circuit?
Let me show you what I have tried so far. First of all, the circuit below has been tested and this one works for sure. The audio signal can be heard on an FM radio at 100MHz.
The second below is ...
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Constant voltage intercom / PA: 25v and 70v on speaker cable?
I am tasked with hooking up some old analog constant voltage intercom and public address speakers to a new digital / networked intercom system. This is currently all shut down and not being used.
...
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99
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Power supply transformer replacement
First of all I apologize, I am not an electronics expert, just fairly good at it, but now I am faced with this weird problem that I can't figure out.
I needed to replace a transformer on a power ...
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How much gain is possible with the LM4880 while avoiding distortion?
In the above schematic, the volume even though at maximum was very low, so I took R32 and R34 out, shorted the path and then was much better but still not so loud (subjective ok). The LM4880 is unity ...
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Audio amplifier design using an amplifier to pick up the microphone output and drive an 8Ω speaker for a 4W output
I am studying analog circuits and see a problem in my textbook (Sedra.)
In the problem, I want to make an audio amplifier to pick up the microphone output and drive an 8Ω speaker for a 4W output.
In ...
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