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Questions tagged [audio]

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

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2
votes
0answers
20 views

How to connect Electret Microphone module and OPAMP?

I am trying to build a circuit that gets electret microphone input and maps into 0-1V for utilizing in ADC. The microphone module suggests using such circuitry When I tried that circuit and talked ...
0
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1answer
140 views

Impedance matching for analog audio from aircraft (high impedance) to USB audio IC

I'm working on a project where we're recording audio from the intercom output of an aircraft. Essentially, this lets us record air traffic and cockpit audio. Aircraft audio is stereotypically high ...
0
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1answer
42 views

Audio Amplifier Clipping

I designed a PCB with the following audio amplifier on it: https://eu.mouser.com/datasheet/2/302/TFA9896_SDS-1381317.pdf According to the data sheet, the amplifier is able to deliver 2.1W RMS into an ...
1
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1answer
28 views

Audio playback information when pressing buttons (school project)

My son is making a display (about A1 sized card) about space for school and I am trying to find out a simple way to add some buttons, that when pressed plays an audio recording with info about ...
0
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3answers
140 views

741 Op Amp Audio Amplifier with Noise

I have a project to build an intercom using op amp 741, because it is easy to find and is the only one that currently has access because of my location. Below the schematic diagram which I designed. ...
14
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6answers
56k views

Over what frequency range can the microphone of smartphone receive the sound?

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?...
1
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1answer
143 views

Driving Lights with Audio Amplifier

I'm working on a project where I want to have christmas lights (or LED strips if needed) react to music. In this case, the end goal is to have them pulse to the beats/bass of the music. There's a lot ...
1
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1answer
125 views

Splitting Audio Out - are there any issues I am not seeing?

first post, so I hope this isn't TOO stupid a question. I am planning on building this circuit: https://github.com/trash80/Ym2149Synth/blob/master/Ym2149SynthSchematic-V29082016.pdf which eventually ...
0
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0answers
15 views

MC34118 Voice Switched Speaker Phone Circuit Not Working

Video demodulation and modulation is performed in the project. At the same time by taking the same signal DC blocking with the capacitor, the audio signal is passed through the MC34118 integrated ...
0
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1answer
192 views

Studio Mic --> 3.5mm jack not working

I have created a system to plug my studio mic (MXL 990) into my MacBook's 3.5mm headphone jack that consists of the following system: Mic -> AC Power supply for the mic -> 3-Prong microphone cable to ...
0
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1answer
93 views

How to record a speaker?

Complete noob here. I don't need a ready to implement solution, pointers on what to read upon and ideas for even simpler projects to gain experience first are perfectly fine. I'm trying to feed both ...
1
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1answer
150 views

Buffer, amplify, filter, sample - In which order?

I'm trying get an audio signal from a high impedance source (guitar or mic) to an ADC. Some casual research suggested that I should filter my signal before amplifying it. My current mental design is:...
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2answers
85 views

Configuring Frequency Bandwidth and Input Signal for Bandpass filter circuit

How do I set and configure the frequency bandwidth I want the filter to output to a device? I am using a physical passive bandpass filter which I intend to take the signal in and filter it and output ...
3
votes
1answer
222 views

Amplify Raspberry Pi Zero W Audio with 60s Tube amplifier circuit

First of all, thank you for taking a look at my question. Electronics is not my field of expertise, and I have found myself a bit stuck. I have been restoring some old 50s and 60s tube amplified ...
1
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1answer
289 views

Opamp Design for Low Impedance Sources?

I am terribly confused ... I tried myself at building a low impedance guitar pickup some time ago. Quick LowZ Pickup Intro Basically just two loops of aluminium with two magnets, a humbucking guitar ...
1
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0answers
46 views

Can I make this Bluetooth speaker stop cutting off its speakers when audio signal goes silent?

I have a simple Bluetooth speaker that always seem to cut off its speaker circuit when the audio stream goes silent. This makes an audible popping noise, which is repeated when the stream starts ...
1
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1answer
78 views

What type of audio output does this symbol represent?

I have this picture. I want left, left ground, right and right ground output. Pin. But I can't understand it. Can somebody please help me. Thanks.
0
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0answers
71 views

Audio amplifier instability inexplicable [closed]

here is the problem, I've designed a power amplifier of which I cannot post the schematic for security reasons, I hope you can help me the same by describing the problem. It is an analog amplifier in ...
2
votes
1answer
157 views

Can I connect a MEMS mic directly to this spectrum analizer chip?

I have a ICS-40181 MEMS mic and want to do basic spectral analysis using the popular MSGEQ7 chip for the purpose of a sound reactive project. Can I simply connect one into the other (with cap/res as ...
0
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2answers
189 views

Op amp zener clamp design

What are the drawbacks of this design vs a design like the TI one here? Should the feedback be on the other side of R2? Are there any other gotchas using something like this, vs limiting using a 7v+-...
0
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0answers
25 views

Difference in output between digital codec and analog filter

I'm working on a project which deals with filtering audio signals with a Low Pass Filter and amplifying the output. Currently, we are solving this using the TLV320AIC3111 audio codec by Texas ...
0
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4answers
123 views

Is there a data transfer limit for virtual serial ports

I want to record 5/10 seconds of audio using an electret microphone and an STM32 nucleo development board and send it to my computer in real-time to be processed. I'm a beginner so I'm sure I'm making ...
0
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1answer
37 views

What does changing the volume on a Bluetooth audio device really do?

For example, when playing audio from a smartphone through car speakers, you can change the volume on both the phone and the car. It makes sense that when changing the volume on the audio controls in ...
2
votes
1answer
191 views

Why would this Class D Audio Amplifier have low current draw?

Disclaimer: Saying I have very little knowledge of electrical engineering theory is an overstatement. I very much appreciate your help and patience. I'm not finding any questions similar to mine, but ...
1
vote
2answers
338 views

How can i replace a electret mic input with headphone output as input

I'm using a SIM800L GSM module for my project. In this module there is a electret mic input pin but I want to give audio to this module from headphone output from a mobile (There is no line in pin ...
0
votes
1answer
45 views

Downsides to terminating a line level audio signal into an amplifier without an output resistor

I'm using a PCM5122 to output audio to a line level output as well as a PAM8406 amplifier. If I connect the PCM5122 to the PAM8406 AFTER the output load RC filter, then there is noise introduced ...
0
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0answers
20 views

Advice required re audio output stage for UM3561

I'm OK with digital electronics, fully capable of popping a 2n2222 and a suitable base resistor onto a GPIO pin but analogue is still quite a mystery to me, hence I'd appreciate some design advice ...
0
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3answers
99 views

8 ohms and 4 ohms speakers wired in series - volume issues

I have two identical sets of ceiling speakers connected to a cheap 2 channel Chinese micro amp - one 8 ohms and one 4 ohms, wired in series per channel. The 8 ohm speaker is too loud when the volume ...
0
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2answers
59 views

3.5mm Push to Talk Switch

I am looking to take a 3.5mm microphone line, insert a press button switch (a foot pedal in my use case) between the headset and the computer. I would like the switch to mute the mic connection when ...
0
votes
1answer
182 views

Op-amp control theory

back at it again trying to use your genius brains. I have been trying to teach myself audio amplifier design. The big road block I am getting into is the control theory part of it, meaning how does ...
0
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1answer
27 views

Audio codec output detection

I am looking for guidance on audio functionality test over USB audio codec. This audio output serves as Alarm to indicate certain events. The signal flow is ARM processor USB port --> USB Codec --> ...
0
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0answers
61 views

What do I need to make an Auto-Decibel Recorder?

I want to rig up a decibel-level sensor to an automated script that will record the times and decibel levels of door slams when I am not present, for later evaluation. I am a capable programmer and ...
0
votes
1answer
60 views

how to increase output power of multistage audio amplifer?

In the circuit given below, I'm working on an audio amplifer. It is driving a 4-Ohm load (speaker.) Input : 1.1V peak-peak sine wave of frequency 1Khz. Input dc = 12v Output : 4-Ohm load. Gain = (8 ...
1
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1answer
128 views

Repair lifted ground pad on power amp

I'm repairing a 250W bass power amp board and one of the problems is that the pads for two ground wires have lifted off the board. It looks like it has had something of a bodge repair done before and ...
1
vote
1answer
167 views

THAT4315 audio analyzer - capacitors getting hot

I have designed a audio spectrum analyzer circuit with THAT4315 and a drivers for IN-13 bar graph nixie tube to visualize the signal level. To supply +-12V to the opamps, the Meanwell NSD15 module is ...
3
votes
2answers
210 views

Enhancing the bass response of an audio isolation transformer

Below is a simple buffer circuit using an isolation transformer : The green trace is the output of the transformer and the blue trace is the input signal (20hz to 20Khz sine wave). As you can see the ...
0
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3answers
76 views

AC to DC rails sag excessively when loaded

I'm just experimenting with rectifying a 120v to 12v dual winding transformer and smoothing it out two a dual rail power supply while I work towards attempting to build a clean power supply. I ...
0
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1answer
88 views

Audio amplifier with strange open loop, is it an oscillator?

straight to the problem. Here is a picture of frequency response of my amplifier in the simulator (LTspice or Pspice both give same results). Normally, in the open loop i see a phase of 90° which ...
21
votes
6answers
5k views

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 ...
0
votes
2answers
162 views

Audio ADC voltage level SNR question

I keep looking for Audio specific ADCs and the majority of these devices work at low voltages on the analog circuitry (5V for example). Lets say we want to process an higher voltage audio input ...
0
votes
1answer
76 views

Do passive RC filters need ground?

So, after a bit of searching I can't seem to find an answer to this anywhere, at least not in an easy to understand manner. Ok, lets set a scenario, if we have an audio input (in my project it would ...
0
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0answers
27 views

How do I convert this ADC code for STM32F3 to STM32F4 for colorchord?

I am currently trying to make the ADC driver code for the STM32F3 version of the colorchord https://github.com/cnlohr/colorchord code work on an STM32F4, as my F4 does not have an on board microphone. ...
2
votes
1answer
168 views

fixing the amplifier in an old arcade machine

I just joined and need help. I'm trying to fix the amplifier in my Chicago coin speedway arcade machine. It basically works but it has a bad hum in it. I did replace a couple capacitors that were ...
0
votes
1answer
207 views

Start/ stop 5v motor from headphones jack

I would like to make the jaw of a plastic skull open/close based on words spoken by a Raspberry Pi. I can make the Pi send the audio to the headphone jack, and would like to use this output to run 5v ...
0
votes
1answer
161 views

Would it be ok if I try to measure an audio signal using a 15m BNC Cable?

I would need to use a 15 meters BNC Cable (RG58) in order to measure an audio signal that goes directly to a pair of earbuds. This means, the test point would be exactly before the balanced armature ...
0
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1answer
83 views

High vs Low audio transistor hFE (DC Current Gain). Which is better?

I'd like to preface by saying Rest in Peace my SoundBlasterX's back-panel transistors. What I tried to do, shown in the images below was ground the copper heatsinks I had glued onto the metal side of ...
0
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3answers
83 views

TDA2030L Audio distortion at high volume

I am using a TDA2030L audio amplifier to make my own subwoofer at home. The amplifier works well with the sound input (from a PC) at around 14 percent. The power input is 19V and 2A which is about 38W ...
0
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1answer
248 views

MICBias Ground in audio codec

MICBias is the voltage required for microphone to power and record signal at full levels. What will happen if we ground MICBias, is it means we are disabling microphone.
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0answers
36 views

Sony Home Theatre Reciever producing high frequency constant volume noise while powered on

Equipment: Sony Digital Audio Control Center (Digital Cinema Sound) Model No: STR-KG700 Problem: High Pitch Buzzing coming from speaker output and headphone output (when plugged in). I have tried: ...
1
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1answer
318 views

Common audio signal voltage range on Line out connector

What is typical audio signal voltage range on Line out connector of consumer electronic devices? (Vmin/Vmax) I need specify Input voltage range to calculate op-amp. ...