Tagged Questions

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

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1
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2answers
27 views

Which microcontroller for audio synthesis/processing?

I want to get started designing my own hardware (digital) audio devices for signal generation and processing. The end goal is to design products which will be part of a modular synthesizer system. ...
1
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1answer
30 views

Linking amplifier to sound organ causes fault

I have put together the Chaney Sound Organ (http://www.electronickitsbychaneyelectronics.com/prodinfo.asp?number=C7025) and replaced the microphone input with a rca plug. I tested this with a sansa ...
1
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2answers
58 views

negative base current in NPN transistor?

I'd like to create a simple circuit that makes an LED brighter depending on the amplitude of an audio signal. My idea is to use the following schematic ; simulate this circuit – Schematic ...
-1
votes
2answers
67 views

Pseudo RF in embedded boards

I noticed that wifi-capable embedded boards integrate the RF into the board design instead of having a separate, add-on wifi card. They have meshes that are etched into the board and the rest of the ...
0
votes
1answer
40 views

Where to find a belt for my REVOX B77 MKII reel 2 reel? [closed]

I am totally conscious that this is an Electrical Engineering forum, but I would welcome any input on where to ask for this request. Please take a look at the pic below : The belt whom dead parts ...
0
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0answers
22 views

How to program DSP inside ADAU1772 codec?

I have read ADAU1772 audio codec datasheet but there is no information about internal DSP's instruction set and how to program it. There is a guide for evaluation board with ADAU1772 but I do not have ...
0
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3answers
84 views

Audio Signal Switching - “DPDT switch vs. 4066”

I've got a signal coming from an electric guitar and I need to switch it. Basically it's a distortion circuit. I need to switch between the distortion and clean (directly connected to the output) My ...
1
vote
1answer
40 views

Converting analog stereo to digital stereo

Analog stereo has two channels. One for every speaker. Now, when can sample and convert the two streams of data from analog to digital. But the problem, is what we will have is two streams of digital ...
2
votes
1answer
63 views

Advice to improve my microphone circuit

I'm still working on a circuit to hear my heartbeat. I've come a long way but it still doesn't sound as good as some example recordings I've heard. I was wondering if someone could spot something ...
1
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2answers
75 views

How to make audio using ultasonic transmitters

I have an idea for a project that involves two ultrasonic beams colliding in mid-air to make a sound. However, I have a few questions. Will this even work? I've read of this type of thing being done ...
0
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0answers
53 views

Audio via transistors

Is it possible to push an audio stream through transistors or a DPST relay? I'm using Arduino to do selection between two audio sources and two destinations, and I've completed the first part which ...
0
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2answers
61 views

How to halve a frequency with analog circuitry while preserving signal integrity?

The question is simple, the answer I'm not sure... How could I pick up an analog audio signal, divide it's frequency by 2 (one octave lower) and send it back on it's way? I could do this by sampling ...
2
votes
1answer
71 views

Grounding for car stereo adapter PCB

I've built an audio adapter for car stereo system. It contains microcontroller, a connector to stereo system (a few data pins and line-level audio output), Bluetooth audio module (RN52) and power ...
0
votes
1answer
61 views

Simple 9v powered amp/preamp

I have attempted to build many amplifier circuits with little luck. The audio is either severely distorted, the gain is not high enough, or I pick up FM and AM broadcast stations. I would like to ...
0
votes
0answers
10 views

Dont know where to connect HD AUDIO or AC-97, & USB [migrated]

I'll provide pictures so you guys can see, but basically I recently bought a new case for my pre built lenovo k330b. I cant find how I'm supposed to position the connectors. Please help me out with ...
1
vote
1answer
85 views

LM386 audio amplifier circuit does not work

I am building a low voltage audio amplifier using LM386 op-amp. I got the datasheet from the manufacturer's website and looked at the pins and their functions. ​After, I designed my own simple ...
2
votes
1answer
87 views

Using diodes to mix 2 audio signals into one set of speakers

I have the audio output of 2 computers connected to only one set of speakers. Each computer uses one of these external USB sound cards: And I use this splitter cable to wire the signals together: ...
0
votes
0answers
32 views

Creating an audio switchbox for room

I have a lot of audio devices and applications including synthesizers, amp, surround headset, DAW, etc. I want a way to be able to "join" these through a central switching panel in my room - something ...
1
vote
2answers
171 views

Jack barrel contact diagram?

I've come across this diagram, I researched a bit, but I don't get what this contact is supposed to do. The circuit below is an audio effect, and I'm confused because it apparently doesn't mean that ...
0
votes
2answers
66 views

Play audio from raspberry pi through my car's disc changer

I'm interested in trying to buy a raspberry pi and create a small bluetooth / airplay type module that I can plug into my car somehow and get wireless audio streaming. I don't necessarily care about ...
1
vote
1answer
51 views

Using Nexys 4 audio port [closed]

I have a digilent Nexys 4 board that I am using for learning Verilog. I have written a code that requires connecting an audio speaker to the board for evaluating. What is the speaker that can be used ...
1
vote
1answer
109 views

VCA Using JFET and Op Amp

Just messing around with LTSpice I came up with this VCA that simulates shockingly good for what it is: I don't recall ever seeing the use of an op amp to mix the signal and control voltage in an ...
0
votes
0answers
61 views

Can a PC sound card (realtek) be used to transmit radio signals

If I were to use software such as PureData to generate a 20 KHz sine wave and perform AM on the wave, played it out the line-out on the right channel, with the ground and the left channel sent to a ...
0
votes
0answers
52 views

Noise on audio circuit when powered by USB

I built a simple microphone boost circuit which works well with a 3V coin cell however when I switch to USB to power it (battery removed, of course), there's a bit of noise in the 200Hz to 10KHz ...
0
votes
1answer
54 views

What frequency range is acceptable for a speaker in an audio amplifier

I am building an audio amplifier using a lm386 amplifier with a 12 volt supply driven from a headphone jack. I am looking for a speaker that will work well in this setup. Currently I am using a ...
2
votes
2answers
140 views

Low voltage audio amplifier clips on 8 ohm loads

Exposition time: One could call me a freshman in electronics and I just designed my first little audio amplifier for headphones. (Pocket design, I want to be able to drive 4 headphone pairs from a ...
1
vote
2answers
42 views

Sampling frequency from audio jack

I want to start a project where i'll sample directly from the audio jack. Now i don't know what the sampling frequency should be. I don't know what is the maximum frequency of sound, i don't know it ...
0
votes
1answer
30 views

Size of passives for active filter

I am working with the CS42436 codec, and in their datasheet, they have recommended values for components to be used in an active filter that takes the differential outputs from the DACs and converts ...
4
votes
2answers
2k views

What data format do audio cassettes use?

How do the sound pressure values correspond to the magnetic domains on the tape? Is the format analog or digital?
0
votes
1answer
32 views

Make outputs single ended on CS4234

I am working with the CS4234 codec for a project It has 4 ADCs and 5DACs. One thing that is confusing me is that the pins are labled AOUT1- and AOUT1+ in the similar fashion for all ADCs and DACs. ...
-2
votes
1answer
61 views

Headphone has no sound if fully inserted in jack [closed]

When I connect my headphone to headphone jack in my laptop, I don't hear any sound. Unless I do not fully plug it in and instead just plug it in around 50%. Sometimes I hear sound but it is all ...
0
votes
1answer
34 views

Impediance mismatch and amplifier question

I am converting an aviation headset to take a Bluetooth signal. The headset speakers are \$150\Omega\$, and the Bluetooth adapter I think is \$10\Omega\$. The mic will not be used. Can anybody ...
0
votes
2answers
59 views

Bias headphone audio signal for use with digital potentiometer?

I am attempting to control speaker volume via a digital potentiometer, the problem being that audio signal goes both above and below 0V, for regular potentiometers this is no problem but for digital ...
1
vote
2answers
254 views

How to improve lm386 amplifier circuit

I am new to the world of audio amplifiers however i am quickly trying to learn. I have built a simple circuit using a circuit based on what I read in the database. The circuit works however there is ...
1
vote
0answers
52 views

SPDIF digital audio to I2S to USB controller

I'm looking to take a digital S/PDIF audio signal, decode it as necessary, and send it to a USB controller chip configured as a USB Audio Class device so I have plug-and-play with standard OS-provided ...
0
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0answers
43 views

Is there a free HE-AAC decoder suitable for ARM MCUs?

Question itself: Is there a free (of charge, but if it's also open source that's even better) audio decoder for HE-AAC (AAC with SBR) that can use the FPU and/or DSP instructions in an STM32F4 ...
0
votes
0answers
47 views

Switching Power Supply makes speakers hiss

I have a computer with a 5.1 soundcard, that I'm using to run a standard PC 2.1 setup (Corsair SP2500) on the main audio output, and two rear surround speakers I had laying around. The speakers in ...
1
vote
1answer
70 views

Compromise needed combining virtual grounds

This is a long story for which I hope my proposed solution to a problem I've created will be a stable one. But op amps can surprise you, so let me explain. The circuit is large and complex, so I'd ...
1
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2answers
105 views

Mic Amp Mixer and Audio Distribution, Won't Work! Help! (Update 2) (Solved!)

I'm new to this forum and I really don't know much about Audio Amplifier Circuits. Hope you can help me. Here it goes: So basically what I'm trying to do is a circuit that mix 3 channels, ...
2
votes
3answers
114 views

Mixed analog-digital power supply

I'd like to build a project where I'm essentially controlling analog signal generation in the audio range from a microcontroller. In other words, an analog synth with digital control. I'm at the stage ...
0
votes
1answer
71 views

Use of Audio Tranformers in Amplification

I came across this ckt to make a wireless ear phones using Infrared Signals from IR LEDs. I am unable to understand the use of Audio Transformer here to amplify the audio signal, instead OpAmps would ...
0
votes
1answer
41 views

Architecture of speaker (drivers) to get an acceptable level with small dimensions

I'm trying for a couple of days now how to get a good volume out of a small speaker. My reference is e.g. an iPhone internal speaker which has a good loudness (up do 100dB) in the higher and middle ...
1
vote
1answer
130 views

Circuits in audio amplifiers to protect speakers

I hear that there are at least two kinds of circuits in modern audio amplifiers solely for the purpose of protecting the speakers against excessive loads on powering on and off. Particular function ...
1
vote
1answer
66 views

From grounding to audio amplifiers

Ultimately I would like to assemble this simple audio amplifier: Given my lack of any significant knowledge in the topic I have several problems and questions. Grounding: In the thread What is ...
0
votes
2answers
90 views

newbie question: can I plug a 250v power strip into a 120v power outlet (and then connect three 120v power adapters to the power strip)?

I'm sorry if the question is too dumb, but I was wondering if I could connect a power strip rated for 250v into my home's power outlet (120v). I wanted to connect 3 power adapters rated at 120v to it ...
0
votes
2answers
67 views

Can you turn a non-USB audio mixer into a USB mixer?

Ok. Pretty sure this sort of thing isn't possible but hey ho, I have a Behringer Eurorack UB1202 multi-channel mixer. I'm just curious if there is any way way to turn it into a USB ...
0
votes
1answer
34 views

How do I find the corresponding level of those audio samples?

I am trying to self-study this problem for a future exam. The writings in red are solutions to the question. I have a problem in number part e of the question where they find the corresponding level ...
0
votes
1answer
61 views

Attenuation in speaker crossover design

In the loudspeaker crossover circuit below, I believe the purpose of the resistor is to attenuate the signal to the second speaker (the tweeter). However, in circuits I've seen that are supposed to ...
1
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0answers
74 views

Noise-cancelling headphone concept

Inexpensive noise-cancelling headphones use a single microphone located in a little lump between the plug and the earphones. They seem to work fairly well for ambient noises, but not for handling ...
0
votes
1answer
71 views

Replace potentiometer with digital version (Speakers)

I am trying to get my PC speakers to be controlled by my arduino. I've taken apart the control and it seems very straight forward, just need a few questions about subbing the manual pots for digital ...