This tag is for questions about designing electronics for measuring, processing, and amplifying audio signals. Questions about debugging or repairing consumer audio players and speaker setups will be closed as off-topic.
-1
votes
0answers
56 views
How to insert a stereo input headphone jack from a 3 watt speaker wiring [closed]
I have here a Bluetooth speaker device that has a 3 watt audio output. Now i was hoping to be able to bypass it's speaker connection by inserting a 3.5mm input socket between. Now my question is which ...
2
votes
1answer
64 views
How can I model the LC output filter for this BTL audio IC using SPICE?
I am using a Texas Instruments TAS5717 in a design. It is a 10W audio class-D amplifier.
For my design, I have copied the schematic from the evaluation board, shown on pg. 17 of this PDF. I used the ...
0
votes
1answer
38 views
Why is my MSGEQ7 circuit giving Arduino analog readings that are so high?
I have built the following circuit based on a proven MSGEQ7 based circuit design, which comes from the datasheet and elsewhere on the internet. I have built and coded to this circuit previously, with ...
8
votes
2answers
177 views
How can I effectively reduce the voltage needed to activate a transistor?
I have built a circuit which basically connects the line out (audio output) of a music playing device to a set of LEDs (actually a huge strip of around 200 LEDs), so they flash in time with the music ...
3
votes
1answer
157 views
How can I modify this circuit for a higher gain?
Here is an image of an amplifier circuit.
How can I modify this for a 10-50 times more gain. I put a wire from pin 1 to 8, but I didn't get enough gain.
3
votes
4answers
157 views
Creating a “Sharp” Turn on for LEDs
I'm building an analog audio VU meter just for fun (no microcontroller). I already have the basic functionality of the circuit working. However, I would like the LEDs that I'm using to have a sharp, ...
1
vote
1answer
64 views
How exactly do USB audio interfaces interface with a computer? (specifically ADC)
I have seen the likes of M-Audio fast track and similar devices that somehow covert an analogue voltage audio signal to a digital data stream which you can connect via USB to your computer. If I open ...
1
vote
2answers
68 views
Powering two 8-Ohm speakers in parallel with a 4-Ohm per channel audio amplifier
Are there any possible problems powering two 8-Ohm speakers in parallel with an audio amplifier designed to drive 4-Ohm per channel? (Both the speakers and amplifier are generic, and the speakers are ...
3
votes
3answers
168 views
Does Solder selection affect signal quality?
I've been wanting to design some circuits for audio processing. I am curious if solder plays a part in retaining signal quality. Is an exotic material or high end lead based solder worth it? Does it ...
0
votes
2answers
88 views
LEDs in the audio path - linearity? [closed]
I'm repairing an ancient stereo multiplex decoder which has diodes in the signal path for mono/stereo switching.
For headroom reasons, I need plenty of Vf on these diodes, which are pulled up by a DC ...
0
votes
0answers
42 views
HDMI Digital audio to RCA Analog [closed]
I'm trying to set up a Wii U which doesn't support Analog Audio + HDMI Video. I got myself a splitter to route the audio to my receiver, but I've hit a wall. My receiver is a nice old Onkyo TX-4500, ...
1
vote
2answers
58 views
Missing connection in amplifier example?
I've been staring at the datasheet for NXP's TDA1308 headphone amplifier IC for a while, and I'm just feeling confused.
Their recommended application circuit (Figure 4 in the datasheet) looks like ...
-4
votes
0answers
53 views
The value of damages caused by audio jacks and USB connections [closed]
I am looking to see what the annual value of damages caused by audio jacks. This would include repairs, units beyond economical repair which are destroyed and the lost of service.
4
votes
3answers
133 views
How do I amplify a dc voltage that is too weak to trigger the base in a transistor?
I'm trying to take the voltage output from a 3.5mm audio jack and have it light up an LED according to it's voltage. I was going to attach the left audio cable to the base of a 2222n transistor which ...
3
votes
1answer
144 views
Are these pcb layouts good?
I'm working on an USB audio interface; the board has an analog section, with amplifiers and filters for the input and the output signals, a digital section, with the DAC, ADC, and the microcontroller ...
1
vote
0answers
57 views
Split any headphone with remote control and mic into Mic TRS+ Headphone TRS+USB
The main question is in the title.
So I bought a headphone mic Y splitter yeasterday, and the right headphone output didn't work. I took it apart and tried to solder it to the headphone jack with no ...
6
votes
5answers
1k views
Why are high end audio connections gold?
Silver has a lower resistivity than gold and is cheaper, so why are high end audio components gold plated?
4
votes
1answer
84 views
Vinyl player emulation on Arduino
Say, you have an arduino uno + audio shield, a speaker and a jog-wheel (or mouse scroll-wheel).
And you want to play some audio-file tied to the movement of the wheel, just like you move vinyl disc.
...
-2
votes
0answers
46 views
Digital Audio Filter: Delay, Echo, and Pitch Conversion [closed]
I'm using dsPIC Starter Kit (DM330011).
And I want to put those three stuff as a main functions.
Delay: when you speak on Microphone to record it and play it through speakers, hear your voice in 2 ...
0
votes
0answers
90 views
Problem with impedance matching on DIY 4 pole 3.5mm audio splitter
I built an audio 4 connector 3.5mm splitter. The goal is to play a sound clip through a phone's mic input across a call, while recording the same sound clip on the computer. I used the TRRS ...
2
votes
2answers
119 views
Bipolar Op Amp w/ Near Zero Offset?
My understanding is that if source resistance is low, a bipolar op amp has 10dB less noise than a JFET. I prefer the JFET op amps because the input offset is so low that you can eliminate coupling ...
0
votes
2answers
104 views
Reducing noise in an audio amplifer using opamp
I am trying to make an audio amplfier using an opamp for a project. It works kind of okay but the only issue is there seems to be a lot of noise in the output of a 0.5 watt speaker. I have tried ...
0
votes
2answers
88 views
RC circuit and tone
Can I generate a tone on an 8-ohm speaker using a 5VDC power source, resistor and capacitor? For example if I want to generate a 440 Hz tone, could I use resistor capacitor values such that RC = ...
1
vote
1answer
101 views
mp3 player shield make noise
I'm using mp3 player shield from sparkfun and Arduino UNO. Everything is ok, I formated my samsung micro sd cards with FAT, I converted mp3 files with ffmpeg, I load the examples file and modified ...
1
vote
1answer
85 views
How to make a cable to record cockpit intercom?
I would like to record the cockpit intercom with my iPhone and a recording app. I do not know much about impedance matching (other than what it is).
I would like to make a cable that plugs into ...
-1
votes
1answer
113 views
How to match audio impedance? [closed]
I have an audio source designed for a 600ohm speaker. I would like to use this audio source with the speaker it is designed for as well as record the source using the standard mic-in on a GoPro. How ...
-6
votes
2answers
146 views
Simple amplifier Cuircuit [closed]
I am new in electrical transistors. My project is to make a 1 watt audio amplifier. Can anyone provide a best amplifier circuit using darlington pair and 2N3904 transistor. i searched google. So ...
0
votes
3answers
71 views
Microphones disturbed by capacitance
I've used several KE 4-211-2 Sennheiser microphones to assemble a device for acoustic signal analysis. They are connected to a National Instruments data acquisition device with ~1 m long cable and ...
0
votes
2answers
104 views
Car CD reader mod to read mp3 disc
I read the article: Modding a CD ROM drive to read DVDs. In my car trunk I have a 6-CD changer. However, it can read only audio CDs. Would it be possible to change the laser head (or adjust it) to add ...
-1
votes
1answer
73 views
Talking Tom Hardware [closed]
We want to make Talking Tom doll.
Talking Tom is an IPhone App. When you speak to it, it echoes your voice with voice of child.
Is there any ready scheme to construct it.
I mean scheme from mic to ...
-3
votes
1answer
65 views
Best way to Interface with PC/MAC/iDevices/Smartphones [closed]
What do you think is the best way to communicate a hardware with PC, MACs, iDevices and Smartphones (with Android, Windows Mobile, etc.) ?
We need to make a voice chat (like VOIP) and also exchange ...
1
vote
5answers
310 views
MOSFET or Transistor for using as switch for audio signals
I was wondering which component is better for using as voltage controlled switch for audio signals (e.g. music signal from mp3 player). Should I use MOSFETs or transistors? The max rail voltage is ...
0
votes
1answer
92 views
Replacing a condenser mic with a MEMS mic
I'm working on a black-box piece of electronics which has a cylindrical "condenser microphone" with a main body diameter of 4 mm and height of 1.5 mm
I want to replace the condenser mic (black box) ...
2
votes
2answers
142 views
I want to connect mic to audio output in arduino?
My knowledge in electronics is poor.
I want to output audio stream from mic to audio
And I use following code in Arduino
...
2
votes
3answers
242 views
Best way to go about biasing a Class B audio amplifier?
I am trying to bias the class be audio amplifier in the provided pdf. None of the resistor values are correct so the bjts are unbiased. What is the best way to go about starting to bias this?
...
2
votes
2answers
172 views
Designing parallel RLC band-stop filter in series with load from f0, gain, Q parameters
I've been trying to design a band-stop filter for my headphones to cut back on excessive highs and to provide a more flat frequency response.
With a software EQ and lots of tries, I managed to arrive ...
3
votes
2answers
330 views
LM386 audio amplifier not amplifying
This is my first attempt at making a really simple audio amplifier. The schematics are below:-
First I tried connecting the circuit to a 9V battery. (Multimeter reads around 8.3 Volts, which is in ...
1
vote
2answers
176 views
Shorting ground and left (or right) of 3.5mm audio jack from the computer
I'm trying to build a shutter release for my Canon SLR that is controlled from the computer. Since the shutter release is simply shorting two points on the headphone jack together, is there a way to ...
1
vote
1answer
87 views
voice activated circuit with static burst [closed]
I would like to build a circuit that will activate when it detects a voice and when the voice stops to make a static burst sound like a voice activated radio.
What I am trying to do is make a voice ...
3
votes
1answer
101 views
How to interpret microcontroller ADC module on datasheet? Datasheet syntax question
I am currently working an Atmel micro controller, the EVK1104S, which has the UC32 Data Sheet. We have actually planted this chip on a custom PCB and are in the process of writing more firmware.
...
1
vote
2answers
73 views
How to reduce an audio signal to proper input level?
I'm working with an audio ADC that supports a max audio input of 500mVRMS before it will start clipping. This is sufficient for lots of equipment that does a 1VPP/.35mVRMS line level, but I'm finding ...
2
votes
1answer
119 views
Audio 3.5 mm jack unique hardware key for iOS/Android
Here is the situation. Let's say there is a set of small devices supplied with an audio 3.5 mm jack. Each of these devices represent sort of a unique hardware key value (say just a number or a ...
-2
votes
1answer
116 views
replacing plug on headset with volume control
I have a pretty expensive set of philips headphones with a volume control on the lead that lost sound in one ear, I couldn't fix it and keep the original plug.
Having removed it, I'm at a loss as to ...
0
votes
2answers
190 views
How to detect line level audio signal?
I'm planning to build an automatic switch box for line inputs to my speakers. The switching itself seems fairly straightforward (a pair of de/multiplexers), but I don't know how to detect the audio ...
1
vote
1answer
84 views
Can I convert audio signals from an iphone to electrical signals to control another device?
I wish to design a mobile app that will allow me to touch parts of the screen, generate a music tone that will be converted to an electrical signal to move part of a toy. By touching different parts ...
3
votes
3answers
494 views
How to get fundamental frequency of a signal using autocorrelation?
I am trying to get the fundamental frequency of a signal that only has a single pitch. I coded out the autocorrelation function using FFT and already got the autocorrelation result. Unfortunately, I ...
1
vote
1answer
155 views
What makes the buzzing sound when touching an audio line?
I recently built an audio amplifier based on the LM386. When I touch one of the input signals with my finger, I can hear a buzzing sound on the output. I checked with the oscilloscope, and there ...
-2
votes
1answer
139 views
Easiest Way to Split Audio [closed]
I'm looking for the easiest way to split audio, and I couldn't find a splitter ic. I'm using an msgeq7 that combines the two channels, and I like to have a splitter before its combined so that I can ...
0
votes
0answers
48 views
I want a gsm module that could be attached with a mic and could transmit the voice to my mobile .. is that possible?
I'm making a project so that I place it somewhere and when I call it I could hear what's going there .. so I want a gsm module that could be attached with a mic and could transmit the voice to my ...
1
vote
4answers
173 views
Smallest circuit to make a sound
I'm looking for the smallest circuit to make some noise. This sound has to be constant and annoying, it's intended for the alarm on a timing device. Any ideas?
The circuit will be triggered with a ...
