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

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1answer
26 views

In current mobile phones, what are some specific techniques that prevent handling noise (rubbing, jostling) from being picked up by the microphone?

I've noticed that when using my smartphone the vibrations from my actions aren't picked up, or are picked up very faintly by the microphone. I've worked quite a bit with microphones and I know it must ...
0
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0answers
25 views

Simple Headphone & MIC Audio Mixer for PC Soundcard

This is a mixer On the left side we have headphones mono (Both left and right channels are common) and the other is microphone. So R2 (50K Ohm) adjust the volume for Microphone and R1 (50K Ohm) for ...
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2answers
56 views

Mixing multiple “boolean” audio signals

I want to mix up to 4 rectangle audio signals which come directly from a microcontroller's timer output pin and contain only one frequncy each. For example, if the microcontroller outputs 400Hz and ...
0
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0answers
30 views

Intel Integrated Audio Signal Path [migrated]

I have a Dell Latitude C840 laptop. It has Intel Integrated Audio. Intel 82801 CA/CAM AC'97 Audio Controller. It has been giving me problems. Sometimes I get chopped or truncated audio, or strange ...
3
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4answers
526 views

Is there a technical reason not to use RCA jacks for speaker connections?

I'm designing a home-made amplifier and am trying to choose connection options for the speaker outputs; is there any reason that RCA plugs are inappropriate, assuming I control the full system, ...
0
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1answer
67 views

What is wrong with my guitar amp?

I found this 1W guitar amp design on the Internet: http://www.diale.org/punch.html And I am trying to build it on the protoboard. I could not find the IC TDA7052, instead I've got the a TDA7052B. ...
-3
votes
1answer
48 views

Desk Speakers DIY [on hold]

Although I don't have much experience in building this kind of stuff, I would like to try to build my own desk speakers! I wanted to know if it's better to have active or passive ones, and if you ...
0
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1answer
40 views

How can I add volume control to this setup?

I have one receiver and one subwoofer that routes high-range signals to 2 speakers. I have 4 speakers in total. Two front speakers and subwoofer connect to the receiver. The two back speakers ...
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0answers
25 views

Bluetooth serial to bluetooth audio module

I was looking to work with a bluetooth audio module but many of the available options are either very costly, unavailable in my region(India) or generally lack some features. What is commonly and ...
1
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1answer
29 views

Merging right & left signals to mono with aop?

Sorry for my english i'm a young french. I want to design an audio transmitter to connect my pc to my Hi-Fi without Jack cables. For now i just want to send a mono signal because sending a stereo ...
0
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1answer
22 views

Samsung Galaxy Microphone and Audio Recording Specs [closed]

I'm a documentary Filmmaker who's interested in exploiting the Audio recording capabilities of the Samsung Galaxy S6, S5, Note and Alpha on their own [Audio recording only] as well as in conjunction ...
1
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2answers
128 views

Microphone connection diagram

I am trying to replicate project Jasper of raspberry pi. Currently I am using a USB to audio converter (shown in image below) and a regular PC mic. However the audio reception range is very small. So, ...
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1answer
46 views

Is this a class A type audio amplifier circuit?

please find the amplifier ckt attachment with this.i got this ckt from your page. can you please tell me, this is class A type audio amplifier ckt? i want to make this amp. and what is the power ...
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0answers
9 views

How could I add TLV320AIC23 codec to the Beagle Bone Black kernel?

I have a chip that uses TLV320AIC23 codec driver for playing audio. I want to drive this chip using the BBB board. But this codec does not exist in the BBB kernel menuconfig. How could I add this ...
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2answers
63 views

Need simple audio amplifier

I'm more of a programmer then a circuit designer (read: I'm not good with EE stuffs at all) but I'm working on an arduino project and it's not loud enough. I was trying to drive a piezo buzzer to make ...
0
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1answer
37 views

impedance matching and impedance briging

Why in RF receiver we need impedance matching for maximum power transfer but not maximum voltage? And why there is no Impedance matching or Power matching in audio engineering? Is it depends on the ...
1
vote
1answer
49 views

Output Radio Circuit Board to Speaker

I have a AM/FM radio board I found and am trying get playing through a small speaker. The other components were missing so I don't know how this connects to the rest of the system which had a CD ...
0
votes
1answer
53 views

Audio hack: replacing electret mic with phone audio output

I'd like to feed a module with audio output from a phone's jack instead of the mic the board cames with. As I said the board is designed to operate with an electret mic with the following specs: ...
0
votes
1answer
76 views

Passive audio phase shifter (180°) - can it be done? [closed]

I understand that most analog hardware phase shifting circuits seem to use OpAmps to get their job done. I am trying to build a tiny, non-powered in-line adapter for Mp3-players and such to quickly ...
0
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2answers
45 views

Resistor values for a passive audio mixer?

I'm trying to come up with a schematic for building a passive audio mixer for an aviation headset, but I'm having some questions about resistor values. Figuring out the general circuit is easy ...
0
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1answer
52 views

Reverse audio jack for front and back speakers

My problem is a strange one. I have a computer connected to front and back speakers via 3.5mm audio jacks. Sometimes I use the computer with the monitor at my desk. Other times I'm using it to watch ...
0
votes
1answer
37 views

Choosing an Audio D/A converter for I2S digital audio based on 32fs

I'm hoping someone can either verify or clarify my understanding of interfacing an Audio D/A converter to a device that sends audio over I2S. I have an Audio Codec chip, the VS1063A (Datasheet), ...
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1answer
50 views

Power supply issue with LM384 audio amp

I made an audio amp using the LM384 : My soldering skills aren't great but eventually the circuit itself doesn't look too bad. To power it, I used an old laptop power supply (18.5VDC - the datasheet ...
0
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1answer
37 views

dB A and dB Z (or dB SPL) Table

Does anyone have a detailed dB A to db Z (or dB SPL) table? I have found one at http://www.cirrusresearch.co.uk/blog/2011/08/what-are-a-c-z-frequency-weightings/ and at ...
1
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1answer
22 views

Headset input crosstalk, or how to mitigate the effects of common ground resistance

I am building a cable to connect a guitar (or a piezo) and headphones to the TRRS connector of a smartphone through 4-wires cable splitting at ~1 mt from the connector. I am experiencing a ...
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0answers
46 views

perfect square wave cannot be played back

If I produce a square-wave by creating a sine wave first and then doing, if x >= 0 return 1, else return -1 this produces a "perfect" square wave(python code). Like this the audio signal cannot even ...
1
vote
1answer
69 views

How does this Audio ADC know which rate to sample the audio at

The part under question is PCM1808. This device needs an external system clock on the SCKI pin. From the master device it shall need LRCK, BCK & DOUT. The LRCK chooses the left/right channels. BCK ...
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0answers
44 views

Adjusting ground level to 1.5 volts for LM386 audio amplifier

I am attemting to use an STM32F4 Discovery to play music through LM386 amplifier. I have tested the LM386 circuit with a spliced headphone and mp3 as input and now attempting to play the music off one ...
0
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1answer
28 views

Where would be the best spot to put a logarithmic volume control on this TPA3122 audio amp?

I'd like to add a volume control to the following circuit (a 2x15W Class-D Stereo Power Amp Kit). The schematic below is an image clipped from a PDF I found describing it. This'll be being driven ...
0
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1answer
68 views

Convert dB A to dB SPL

I am trying to calibrate an audiometer that gives outputs in dB SPL. However, the sound meter that I am using to calibrate the audiometer registers in dB A. Is there a formula to convert from dB A to ...
0
votes
2answers
72 views

Microphone amp getting only 1x gain?

I'm trying to build Sparkfun's sound sensor and testing the first stage only. Here's the first stage: If I scope before C2 and at Pin 1, I get the following when I scream at it: where Ch1 is the ...
1
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1answer
75 views

Audio Amp-Calculate Current gain of a Push-Pull BJT Pair (and remove Beta Dependence)

I was designing an audio amp for a final project for an electronics course. We were given a very vague set of requirements and told almost nothing about our input signals or desired output minus ...
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2answers
45 views

VOX circuit false triggers when touched

I built a VOX circuit (Voice Operated Switch) which is an audio activated relay that activates when sound is applied from a USB sound card on my computer. I am having a problem with the switch, ...
0
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2answers
47 views

Determining the frequency response of an audio crossover (something seems off)

I'm in the process of putting together an audio crossover. I finished assembling the components, and I though it would be neat to do a frequency sweep on the filters. When I inspected the tweeter ...
0
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0answers
59 views

Having FPGA to output sound on “line out” pin using verilog

I am trying to write a verilog code for FPGA which will output sound from the embedded "line out" pin. I use Quartus II and Altera DE1. I am new to hardware programming, therefore it just takes too ...
2
votes
4answers
104 views

JFET in place of digipot for gain control?

I'm hoping to build a sound sensor using this schematic (http://cdn.sparkfun.com/datasheets/Sensors/Sound/sound-detector.pdf) To programmatically adjust the gain, I could use a digipot. My (naive) ...
0
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1answer
30 views

How is this figure supposed to be interpreted in the datasheet for the LM4766 audio amplifier, and determining the needed power requirements?

First off, I really have no experience when it comes to audio electronics, so forgive me if these are naive questions. In any case, let me explain what I'm doing/trying to do. I have two speakers ...
0
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1answer
36 views

Using an unconnected audio splitter degrades audio signal quality?

Consider that you have one of the following: These are used to connect 2 male audio connectors into only one female connection. Since I can't find, for now, where I have the audio cable extension, ...
1
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0answers
37 views

Analog Microphone Preamplifier

In my design I want to use a quad Operation Amplifier for amplifying the output of an Analog MEMS Microphone before connecting to the CODEC IC. I would also be using the MIC preamplifier circuit for ...
1
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1answer
59 views

Why does my AY-3-8910 sound so distorted?

I'm building a circuit driven by an Arduino UNO that controls a AY-3-8910 programmable sound generator. The AY has three pins ...
0
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1answer
56 views

How can I make the power amplifier stage for this audio amplifier?

How can I implement a Power Amplifier stage for powering an 8 ohm load? I tried making an AB amplifier, but either it doesn't work or I'm just not able to make one. The output of the third op-amp is a ...
1
vote
1answer
63 views

Use of RC circuit in amplifier output stage

I have to use a LM384 amp circuit (shown below) for a school project and need to explain how it works. I've read the datasheet (http://www.ti.com/lit/ds/symlink/lm384.pdf) and thus have a guess about ...
2
votes
3answers
101 views

Measure human voice for ambient noise level

I need to develop an ambient noise level to measure the loduness in an office. Sometimes during the day people raise their voice more than they should and a lot of confusion is created. So this device ...
2
votes
2answers
87 views

Best way to sync LED's to light NES figures on a wall clock?

Advice & Ideas needed... Working on a project - a custom wall clock with perler bead NES sprites in the place of the numbers. The figures are mounted to a wood board with cutouts underneath, and ...
0
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3answers
55 views

jfet preamp output attenuated and clipped on bottom rail when connected to codec

I am currently working on an embedded audio processing system for electric guitar. I have constructed two JFET preamps (left and right channels) based on the j201 transistor using the common source ...
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0answers
46 views

USB streaming controller

I am developing an Audio codec using the TIs AIC3254 chip. For the interface, they have suggested a USB streaming controller which they no longer support and other alternatives are a full blown Audio ...
0
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1answer
178 views

Adding Bass and Treble control to existing schematic

I have a little project in mind that I want to try. This picture below is a stereo amplifier circuit. For more info about it, you can see this page. Stereo Amp The circuit above only has Gain and ...
11
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4answers
642 views

Can a power MOSFET for switching application be used as a linear amplifier?

Power MOSFETs nowadays are ubiquitous and fairly cheap also at retail. In most datasheet I saw power MOSFETs are rated for switching, without mentioning any kind of linear applications. I'd like to ...
0
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0answers
15 views

Properly securing S/PDIF from voltage spikes

I'm working on a set of devices, each using a 75Ohm Coaxial S/PDIF input or output with a 1:1 transformer for ground separation. I was wondering what is the proper way to add transils or Zener diodes ...
2
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1answer
131 views

Why Do The Wires Inside a Headphone Cable Touch? Can't Wires Not Touch?

If you cut open the wire of a pair of headphones, say Apple Earbuds, there are a whole bunch of different cables inside that look (more or less) uninsulated. My understanding of Electronics is that ...