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

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0
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0answers
10 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
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0answers
21 views

active stereo summing

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
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0answers
6 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
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2answers
45 views

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

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 ...
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0answers
16 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
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0answers
26 views

Why is the volume of audio higher if I use Apple Devices and A2DP? [on hold]

My issue is that I was assuming that if I had the same digital audio file and the same pair of BT Headphones I would hear the same no matter the device that is sending the audio. But that does not ...
1
vote
2answers
70 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
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1answer
42 views

DC Thump-like noise with Isolation Transformer

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
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1answer
22 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
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1answer
100 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
64 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
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0answers
22 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
74 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
68 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
votes
0answers
30 views

drsstc tesla coil musical interrupter

I'm looking for ideas to incorporate the input from 3.5mm audio jacks to provide an output to a DRSSTC. Those familiar know that a DRSSTC gets a short pulse (usually 50-250us) as a pulse train to ...
1
vote
1answer
61 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
1answer
49 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
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0answers
31 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
40 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
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0answers
20 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
52 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
79 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). ...
-1
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0answers
42 views

A: Why does the sound that out after LPF become smaller

I'm trying to make circuit to record and analyze heartbeat sound in my phone through 3.5mm jack. I build the preamp with LM358 like this It works I can hear my heart beat sound, but alot of noise. I ...
2
votes
2answers
261 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
114 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
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0answers
33 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
52 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 ...
0
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0answers
22 views

Audio interface using LPC2138

I am planning to implement Voice guide/Assistant using TLV320DAC3100 DAC and LPC2138 controller. Above DAC has I2S (Inter IC Sound) interface. Unfortunately,LPC2138 is not I2S supported. So, Is there ...
1
vote
1answer
48 views

Toroid Core Selection for Audio Isolation Transformer

I am a newbie. I have attempted to make an isolation transformer with some toroid cores and it worked, but not well. I tried using a "wide band" toroid core and it seemed to have killed a lot of the ...
0
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0answers
66 views

Finding Audio Output on a BeagleBone Black

I need to find a way to measure the start of audio output on a BeagleBone Black Rev C. Audio on a BBB: The BBB does not contain a DAC. The only supported audio output is through HDMI. Measuring ...
2
votes
1answer
45 views

How Much Current Draw From Speakers/Amplifier?

So I plan on using the VS1053 Codec connected to a class D Amp (2 x 2.8W channel) with two 3W 4 Ohm speakers. If I supply 5V to this setup, what would the current draw be at full use? Codec: ...
1
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1answer
44 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 ...
4
votes
1answer
45 views

Why does my LCD screen emit sound when displaying black-and-white lines?

I recently discovered this page (epilepsy warning; flashing lights), which displays horizontal black and white lines and animates their thickness. Amazingly, it makes my laptop LCD screen emit an ...
0
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0answers
61 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 ...
0
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2answers
61 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 ...
3
votes
4answers
552 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
votes
1answer
73 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
49 views

Desk Speakers DIY [closed]

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
votes
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 ...
0
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0answers
29 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
vote
1answer
35 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
votes
1answer
30 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
vote
2answers
167 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, ...
0
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0answers
20 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 ...
0
votes
2answers
89 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
42 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
75 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
62 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
86 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
57 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 ...