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

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0
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4answers
78 views

Remove ground loop hum by 180º phase shift?

I have a homebuilt subwoofer for my surround sound audio system. 400W constant, 900W peak. However, there appears to be an AC hum on the input line, and it becomes especially noticeable when I ...
0
votes
0answers
33 views

DSP + ARM Processor For Digital Audio Mixer [on hold]

I'm currently working on a project where I have been tasked with a team to create a digital audio mixer. I need a processor that preferably has a 1 DSP core and 1 ARM core both running close to or ...
-2
votes
1answer
56 views

Solution for recording audio and uploading it through ESP8266 (IoT)

I am using a STM32F401 Nucleo board and I want record audio through the electret microphone and the ADC. So the first question is how do I record the negative voltages. Do I just clamp the signal and ...
-2
votes
0answers
36 views

Velleman KA02 Problems [closed]

I recently bought a Velleman KA02 Arduino Audio Shield (http://www.velleman.co.uk/contents/en-uk/p579_ka02.html), which uses an ISD1760PY audio chip and soldered it together. The first time I fired it ...
0
votes
1answer
64 views

How to make an Audio Amplifier

I am about to attempt make my first audio amplifier (beyond an LM386 amp). I chose the TDA2030A (dataheet http://www.st.com/web/en/resource/technical/document/datasheet/CD00000128.pdf). Since its a ...
0
votes
2answers
41 views

Audio Taper to Linear Potentiometer

I'm trying to linearize the output of an audio tapered potentiometer. Right now, I'm using ADC on a Beaglebone to read the value of a 250k potentiometer with 3.3V. I get a value between 0 and 1, but ...
0
votes
1answer
27 views

Difference is Bluetooth Smart and Bluetooth audio

My name is Raveen Baloo. I have been doing a lot of research on the types of Bluetooth module. For my project, i do need a bluetooth which will be able to have simple communication with a mobile app, ...
4
votes
2answers
152 views

Driving a speaker directly through an audio DAC?

I have a project where I'll need to generate some sound waves. In case it matters, the microcontroller I'll be using is an STM32L476RG which have an internal DAC. The question I have is related with ...
0
votes
1answer
48 views

Using european telephone cables for own DC power delivery

I have european telephone cables running through my walls to each room, without any connection/socket. Well... we really do not need any hard line telephone connection and I am into DIY projects, so I ...
1
vote
1answer
41 views

audio circuit: zener clamp

I'm thinking about using this circuit to update an old Hafler amplifier. But, I'm curious about the purpose and configuration of the zener clamps in the circuit. I added the red box in the circuit ...
0
votes
1answer
41 views

Dual mode Bluetooth for transmitting audio and connecting with an App [closed]

​Hi my name is Raveen Baloo from Singapore. Currently, I'm working on a project, building a case box which has a MCU and a LCD screen. A removable bluetooth dongle is connected to the case box which ...
0
votes
3answers
215 views

Can somebody please analyse this circuit [closed]

Can somebody explain to me how this circuit works? i understand that it is an audio amplifier circuit and it inverts the signal, and inverts it again, but i am not sure why this is the case. also ...
0
votes
0answers
42 views

How to hookup Ambiq Micro Apollo MCU to Analog SSM2211 for audio playback

I am new to the electronics area. I have been searching on this topic for a while now but I still don't have a clue. Thank you for helping in advance. I understand the Ambiq Micro Apollo MCU ...
3
votes
4answers
66 views

Humbucker-style microphone interference cancelling

For a recent experiment, I decided that it would be a good idea to try to add some electric guitar distortion effects to my otherwise Classical flute playing. In order to do this, I attached a small ...
-1
votes
1answer
67 views

Should bias voltages still be in range without driver/output transistors?

A class AB audio amplifier has both positive and negative +/-40v rails. There is a differential amplifier feeding a trans-impedance transistor. The transistor is also a current source for an ...
3
votes
2answers
40 views

Output power vs idle power of an audio amplifier

Let's say I have a AB class power amplifier that is able to give an average output power of 30W on a 6 ohm loudspeaker. Now in ...
-2
votes
1answer
66 views

Audio op am for low noise high volume

I am trying to make a high quality circuit to take mp3 (stereo) signal and drive a 4 ohm speaker. I have been using the LM368 as in the picture below and this has ok quality when the volume is low but ...
3
votes
4answers
430 views

LED's flash with music

I am wanting to put have a few LED's flash with the intensity of my music. I don't need a color organ, but just want the LED's to flash in sync with the music. I am amplifying the signal with a LM368 ...
0
votes
0answers
38 views

RN 42 to RN 52 communication

I am attempting to connect an RN 42 bluetooth device to an RN 52 device, and then the 52 to a cell phone. The RN 42 is planned on being used a wireless controller, having all capabilities of ...
1
vote
1answer
48 views

Class AB Amplifier Frequency Response

I have designed an AB Audio Amplifier, but even though the gain is acceptable, the frequency response is terrible.As seen in the schematic, there is a feedback/preamplifer stage and an output stage, I ...
0
votes
1answer
64 views

Need help choosing options for 12V supply from a Lithium-Ion battery

There are lots of Class D audio amplifier modules for 12V use that are both readily available and inexpensive, intended for automotive use (hence the 12V rating). I would like to use one of these, ...
0
votes
3answers
592 views

What is the purpose of the 10K resistor that is connected across the input and the supply?

I was checking out some transistor amplifier circuits online when I came across this one. Now my question is what is the use of 10 kilo-ohm resistor that is connected between the power and the input ...
0
votes
0answers
34 views

Calculate OCR2A from audio frequency [migrated]

I'm working on a Arduino-based synthesizer using this tutorial, specifically using a wavetable and 1-bit DAC. I understand that the value for OCR2A register sets the frequency, but how do I calculate ...
0
votes
1answer
48 views

What would the best way to filter high frequency noise? Decoupling/Bypass Capacitor? 1:1 Audio Transformer?

As many high end graphics card have high frequency coil whine and my particular one is causing whine on my diy studio monitors, what would be the best way to filter this noise? My studio monitors are ...
0
votes
0answers
3 views

how to connect multiple power speaker by using splitter [migrated]

I have 5 self power speakers.. I want to connect this speakers to my computer by using 3.5mm audio jack splitter...is this possible ? does it make any effect on audio single or sound quality? and ...
-2
votes
2answers
71 views

Is it possible to make an “easy” high power amplifier? [closed]

For example, an LM317 can handle currents up to 1.5 amps, but if you add a few 2N3055 power transistors you can get pretty much unlimited power (if you have good enough cooling and components that can ...
1
vote
1answer
110 views

Power Transistor for TDA2030 audio amp

I am attempting to make a Stereo Power Amplifier using two TDA2030A amplifiers. I want an output of at least 25 watts per channel. The datasheet shows me that I need to add a pair of power ...
0
votes
1answer
36 views

Will this circuit (for a guitar effects pedal) work?

I am a newbie at electronics and am trying to make a fuzz/distortion pedal. This is a schematic I have made My understanding is that the more resistance the more gain so there is a minimum of 100 KΩ ...
1
vote
0answers
22 views

SGTL5000 codec noise

I built an audio baseboard for an i.mx6 board built by embeddedarm(ts4900). I used the ubiquitous sgtl5000 codec from freescale. While the end result works ok, I find that the output from the line ...
0
votes
3answers
76 views

How to explain the behavior of a PNP transistor as a transimpedance amplifier?

Can anyone explain how Q3 behaves? I mean in a way that: If base of Q3 goes positive ... increases.. ect and if base of Q3 goes negative ... happens and so forth and so on. in that fashion. I see ...
0
votes
2answers
72 views

audio-taper potentiometer in 50-100 ohm range [closed]

Anyone know where to source an audio or logarithmic taper potentiometer in the 50 or 100'ish ohm range ? Mouser and Digikey don't show anything, even non-stocked. I'd like to build an adjustable ...
1
vote
1answer
58 views

How to build an Audio Spectrum Analyzer/Sensor?

I am designing a smart RGB LED strip driver based on a Raspberry Pi and an Ardunio. The Ardunio would controll the LED strip, and other LEDs connected to a shift register, while the RPi would manage ...
-2
votes
1answer
60 views

Add Low Pass Filter to existing Stereo Amp Circuit

I have designed a simple stereo amplifier which is attached below, but the bass output was bit poor. So I'm planning to add extra low pass filter circuit to this circuit. I don't have any idea how ...
0
votes
1answer
47 views

How to increase the output power for this audio amplifier?

I have created this simple single stage, transistor audio amplifier using voltage divider bias. For testing, the source of input signal was audio from laptop and the output was from a 4 ohm, 0.25 ...
1
vote
1answer
71 views

How to improve load transient response of an LM317 voltage-regulator powering an audio amplifier?

I am building a voltage regulator circuit for powering a pair of mini-speakers (about 3-5W) with built in amplifier and an old mp3-player/FM radio. The power source is an old mobile phone charger ...
0
votes
0answers
52 views

FDNR instability

Can anybody advise me, I have made many attempts to make a practical FDNR circuit, but it is always very unstable with lots of RF oscillation. I am trying to make and audio filter, that is the ...
0
votes
2answers
56 views

Arduino Audio Input from AUX cable

I want to feed Audio input (music played in my phone or laptop) to Arduino using an AUX cable(3.5 mm). I know that we need to offset and amplify the signals as the Arduino takes input from 0 to 5v ...
0
votes
1answer
34 views

TPA6111 Stereo power amplifier to mono setup

I have a TPA6111 stereo audio power amplifier part (http://www.ti.com/lit/ds/symlink/tpa6111a2.pdf) that has this typical application (from the datasheet): My application requires a mono signal ...
0
votes
1answer
30 views

WT588D-U use of DAC audio output

U When I use the PMW output with a speaker like this, all is good: http://www.instructables.com/id/WT588D-Standalone-Arduino-sound-player/?ALLSTEPS I want to test DAC output so I did it like this ...
0
votes
2answers
116 views

How are the resistor values R1 and R2 calculated for a transistor amplifier that has a voltage divider bias

Good day friends I am trying to analyse the working of transistor amplifiers with a prime goal of designing a good audio amplifier that does not produce much distortion in the output. I am ...
0
votes
1answer
43 views

Pass line level signal through electric guitar

I have an idea for a project where I want to pass a line level signal through my electric guitar. The idea is to have a 3.5mm jack input on my guitar, to which I can input a line level signal. Then ...
0
votes
2answers
87 views

What to do with unused chip amp channel?

I'm planning to use STA540 in a guitar combo, because it's one of a few chip amps that can give me about 15W with 12V supply and 4ohm speaker. My problem is that the chip has four amplifiers and I ...
0
votes
1answer
41 views

Audio Circuit to Remove Vibrato while Preserving Word Detail

In music, vibrato describes the warble effect often added in by singers as they sing. I was trying to come up with a circuit to remove it from an audio signal, almost like a "vocal stabilizer" ...
8
votes
3answers
325 views

Details on PCB layout for microcontroller

Update: the follow-up question shows my take on the resulting PCB layout. I'm laying out my first board with a uC (I've got a reasonable amount of experience in using and programming embedded ...
-1
votes
1answer
39 views

What is a safe voltage for ultrasonic frequencies being fed to a regular speaker?

In a circuit I am designing there will be high frequency noise output into a speaker at -60 to -80 dBV. It's just that I opted to use a simple 2nd order LC filter (47 uH, 470nF) for delta-sigma ...
0
votes
1answer
31 views

NJM2072D Application Questions for Audio Detection Circuit

I am building an audio switch with channel priorities. I will use this in car events where we communicate car-to-car on FRS radios. A few of us also use 2 meter amateur radios for longer range ...
0
votes
1answer
38 views

Connecting active filters in parallel

I would like to connect a signal coming from a line receiver to several op-amp based filters in parallel. The basic topology (high-shelf) looks like this: simulate this circuit – ...
1
vote
4answers
58 views

Summing amplifier with bypass

I am trying to sum three audio signals using a non-inverting summing amplifier as shown below. If I want to bypass one of those signals, what is the correct way of doing that (let's say with a ...
0
votes
1answer
69 views

Schematic to wiring diagram check for 3 mic mixer circuit using TL081

Need a bit of community validation to see that mapping of the following circuit schematic: to this hand-drawn wiring diagram seems correct, and there are no obvious mistakes: Also, does having 2 ...
1
vote
2answers
31 views

Multi channel variable speaker design problem

As part of my my consideration of possible solutions to my multi channel variable speaker number problem arising from my attempts to restore radio functionality to an old hotel intercom system (see ...