Questions tagged [audio]

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

249 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
6
votes
0answers
520 views

LM386 guitar practice amp circuit not working, need help finding mistake

I'm very new to electronics and I built this guitar amp circuit on a breadboard: and it was working really nicely. Now I've decided to put the circuit on a universal PCB which I'll use in the actual ...
3
votes
2answers
72 views

The Pin 1 Problem in Audio, Star and Mesh Ground, and Contradictory Grouding Practices in Audio and Digital Systems

I recently came across the concept of "Pin 1 Problem" known in the pro-audio electronics. It seems straightforward at first, but becomes confusing when it comes to grounding. Let me describe the ...
3
votes
1answer
188 views

Enhancing the bass response of an audio isolation transformer

Below is a simple buffer circuit using an isolation transformer : The green trace is the output of the transformer and the blue trace is the input signal (20hz to 20Khz sine wave). As you can see the ...
3
votes
1answer
211 views

Amplify Raspberry Pi Zero W Audio with 60s Tube amplifier circuit

First of all, thank you for taking a look at my question. Electronics is not my field of expertise, and I have found myself a bit stuck. I have been restoring some old 50s and 60s tube amplified ...
3
votes
1answer
450 views

How would a transistor's hFE affect a phase shift oscillator?

I have a phase shift oscillator circuit from a drum machine that I would like to reproduce as faithfully to the original as possible. My problem is that the 40 year old design uses a transistor (...
2
votes
0answers
59 views

Designing an audio amplifier, problems with bandpass filter

I am trying to build a Audio amplifier for a university project, I think that most of my circuit is done but I have an issue with my filter as my sine signal is not symmetrical after filtering to ...
2
votes
0answers
75 views

High SNR FM demodulation

So I need to demodulate the FM signal from a sensor with highest SNR possible, at least 70-75 dB. IF is 10.7 MHz, max. deviation is 200 kHz but I can change those values if needed. Baseband signal ...
2
votes
0answers
90 views

How to connect a MEMS Microphone Breakout - INMP401 to a RN-52 bluetooth module?

I intended to use a INMP401 (MEMS MIC) to capture audio and stream it via bluetooth using an RN-52 bluetooth module (RN-52). The RN-52 has inputs for differential +- signals. The INMP outputs ...
2
votes
0answers
160 views

Can I replace electret microphone with audio connector and expect similar results (sound levels)?

Last night I built a circuit that allows me to obtain sound via a SEED Grove Sound Sensor and input it into my MKR Zero for frequency analysis. It's as simple as this: simulate this circuit – ...
2
votes
1answer
147 views

Can I connect a MEMS mic directly to this spectrum analizer chip?

I have a ICS-40181 MEMS mic and want to do basic spectral analysis using the popular MSGEQ7 chip for the purpose of a sound reactive project. Can I simply connect one into the other (with cap/res as ...
2
votes
0answers
58 views

Audio Sampling for Reactive Lighting

I'm trying to work on a reactive lighting project and I'm confused about a couple topics when it comes to sampling audio. I want to be able to have RGB reactive lighting controlled by a ...
2
votes
1answer
155 views

fixing the amplifier in an old arcade machine

I just joined and need help. I'm trying to fix the amplifier in my Chicago coin speedway arcade machine. It basically works but it has a bad hum in it. I did replace a couple capacitors that were ...
2
votes
1answer
209 views

Ultra low power audio recorder

I'm trying to design an ultra low power audio recorder, in order to monitor ground noise in rural areas. The circuit I'm working on is based on a microcontroller (STM32L100RC) and an audio codec (...
2
votes
0answers
253 views

Op-amp circuit saturates to negative rail and only passes positive side of input

I've been working on a spring reverb driver circuit, based mostly on figure 5 from this site: https://sound-au.com/articles/reverb.htm. While there's lots of information on the how of the circuit, ...
2
votes
0answers
206 views

Dual antiphase electret mic preamp topology

I am currently trying to make a preamp for an electret mic pair, which are placed physically in antiphase. The main idea is to subtract one mic's signal from another and therefore boost the signal ...
2
votes
0answers
1k views

Why do some audio amplifiers connect the power ground to the signal ground?

Trying to add a MIDI synthesizer & speakers to a keyboard here. Here's the schematic: simulate this circuit – Schematic created using CircuitLab But I was getting annoying crackling and ...
2
votes
0answers
501 views

Modded speakers emit high frequency noise, how to filter it out?

I came up with an idea to convert my PC speakers into Bluetooth speakers. It's not really a serious project, rather a proof of concept, but I want to get it to work as well as possible. Here's my ...
2
votes
0answers
1k views

HTC 10 DAC/amp specifications

I'm going to be doing a final year project revolving around music production and DACs are pretty important. Not going to go into detail (unless this question requires it) what the project is but I ...
2
votes
0answers
81 views

Audio: Camera activated external microphone

I want to build a relay circuit that turns on an external microphone (powered by an internal 9V battery) when a connected camera is turned on (a camera offering only 1V plugin power through a 3.5 mm ...
2
votes
0answers
243 views

Linear vs. Audio Taper for RC Network

I'm building a distortion pedal and I was wondering which tapers to use for which potentiometers in the tone control section. I normally design my own circuits, but I'm going by someone else's ...
2
votes
0answers
269 views

Troubleshooting audio output on Nexys 2 (FPGA)

I've recently purchased the PMOD AMP1 module from digilent for use with my Nexys 2. When I program the demo project and plug headphones or speakers on the headphone output I can hear a barely audible,...
2
votes
0answers
2k views

Convert a wired headset to a wireless one

new to the board and not caught up with current technology, but I can handle myself when it comes to soldering and small electrical appliances. I have a headset that I really love, but the wire ...
2
votes
1answer
131 views

How does the center tap terminal work in Knowles Speakers ED series?

I would like to understand how the center tap terminal work in miniature speakers. I can see in the datasheet that a positive going voltage relative to this center tap can lower the output volume but ...
1
vote
0answers
46 views

Should I connect metal enclosure to -V or to virtual ground?

I've built a headphone amplifier powered by a switch-mode 2-pin wall wart power supply. Internally a virtual ground is created by dividing and buffering the supply voltage. Input and output signals ...
1
vote
0answers
72 views

Struggling to get an amplified sine wave over a small inductor at low frequencies

I am building a power amplifier circuit to amplify a sine wave over an inductor from a function generator. However because the inductor is small and i'm running at a low frequency I am getting ...
1
vote
0answers
59 views

2 Crossovers in parallel: how are frequencies distributed?

So, the other day I connected on parallel a dual-voice subwoofer-system (a Pyle XSUB1-150-4-12d crossover — like this one ... link might be unavailable after Aug 28, 2019 ... — and 2 individual ...
1
vote
0answers
46 views

DIY high fidelity audio using delta sigma adc

This question may be too general, but I will include all the details that I can. My end goal is to achieve a super high-resolution spectrogram of any recording I choose to make. By doing some tests I ...
1
vote
0answers
43 views

Guitar to iPhone JFET pre-amp circuit issue

I am following this tutorial to build a simple JFET pre-amp to connect a guitar to an iphone. This is the schematic: I have soldered the components as per the schematic directly onto the 1/4" mono ...
1
vote
0answers
42 views

Voltage step up module and if I am using it correctly

I am making a "simple" bluetooth speaker and have followed instructions from a Youtube video on how to assemble the components I have bought. However... I am finding that the rechargeable li-po ...
1
vote
1answer
57 views

Low pass to high pass filter conversion

Ripples from Mutable Instruments (open hardware) is a low pass 4th order filter. The schematic is found here https://mutable-instruments.net/modules/ripples/downloads/ripples_v40.pdf Can I swap ...
1
vote
0answers
40 views

Audio Amplifier Power Usage

I'm looking to add an audio amplifier to a circuit, in this case the TPA0211 in 5V mode for a full 2W of output. My rather dumb question is this: I should expect at least 400mA of current draw from ...
1
vote
0answers
143 views

How to Low-Pass PDM Output Data

I have a PDM-Mems Microphone which provides me with 101010 data, the Microphone has a Clock of 3Mhz. I read the manual about how PDM is generated, but I haven't worked with digital filters yet and in ...
1
vote
0answers
137 views

Low latency wireless audio transmitter

I am working on a project that requires low latency wireless point to point audio transmission at short distance using a digital transmission technique (ideally 24bit 96khz audio, 30 metre max) at a ...
1
vote
0answers
46 views

Why is my signal stronger in the positive than in the negative when i use 2n3819?

simulate this circuit – Schematic created using CircuitLab In the above circuit I have created a JFET amplifier for small signal purposes. When I run tests on the circuit, i get this weird ...
1
vote
1answer
151 views

Why would this Class D Audio Amplifier have low current draw?

Disclaimer: Saying I have very little knowledge of electrical engineering theory is an overstatement. I very much appreciate your help and patience. I'm not finding any questions similar to mine, but ...
1
vote
0answers
168 views

How to make a piezo speaker louder with 5V?

I have connected a tiny piezo pc speaker (https://sktechworks.ca/wp-content/uploads/2017/11/Speaker.jpg) to an arduino and used to tone command to play a simple melody in repeat (square wave only ...
1
vote
1answer
40 views

Induction loop resistance calculation

I have been trying to build a simple induction loop amplifier. I am using TDA2040 as an output stage and it delivers 10 W (I limited it for that). I am using about 14 meters (1 mm thickness) loop. My ...
1
vote
2answers
98 views

Quick question. Will this mono/stereo switch system work on my mixer panel?

So basically, I designed a mixer panel for monitoring my band when we play live. However, some of us play with a stereo in ear monitoring system and some of us use a mono speaker by their feet. I don'...
1
vote
0answers
91 views

Differential bandpass filter Audio application

I am developing an Audio project which is required to output a signal between 10kHz - 40kHz at ±1V. The sound is produced from an AD9106 chip which is interfaced to the following circuit: When ...
1
vote
2answers
184 views

Unstability with tda 2002 bridge configuration

I'm trying, for MONTHS (obviously not everyday, but I spent at least more than 80 hours on this) to do a 15 W audio amplifier with two TDA 2002's in a bridge configuration, following the circuit ...
1
vote
0answers
42 views

Creating a TRRS cable that route the audio from the Left channel to the microphone

So I have an audio interface that output audio via TRS socket what I want to do is to use my iPhone to record the audio coming out from the audio interface. What I tried is to create a custom cable. ...
1
vote
1answer
148 views

THAT4315 audio analyzer - capacitors getting hot

I have designed a audio spectrum analyzer circuit with THAT4315 and a drivers for IN-13 bar graph nixie tube to visualize the signal level. To supply +-12V to the opamps, the Meanwell NSD15 module is ...
1
vote
0answers
153 views

audio output on my FPGA

I asked a very bad question related to this yesterday, sorry - this is more comprehensive and makes more sense. this is the manual for the nexys 4 FPGA i'm using https://reference.digilentinc.com/...
1
vote
0answers
118 views

Identifying Noise in 12AU7 Based Headphone Amplifier

I've been working on making a tube based headphone amplifier as a fun personal project. The amplifier is based around this 12AU7 vacuum tube. The project for the most part is following this existing ...
1
vote
0answers
61 views

phoresistor vactrol tremolo noise

I made an optocoupler by shrink tubing a generic photo resistor and a cold white led. Then used it in the following setup to be able to control audio level to achieve tremolo effect: simulate this ...
1
vote
0answers
116 views

Amplitude Modulating a simple Laser using an RF transformer

I know I can modulate a laser using an audio transformer see pic and website below. Pen Laser website I was wondering if it’s possible to modulate a simple pen laser using RF signals in the RF range ...
1
vote
2answers
291 views

How can i replace a electret mic input with headphone output as input

I'm using a SIM800L GSM module for my project. In this module there is a electret mic input pin but I want to give audio to this module from headphone output from a mobile (There is no line in pin ...
1
vote
0answers
45 views

Subwoofer passive crossovers in series

I have a passive crossover between my amp and subwoofer. However too much high frequency is coming through, I'd like it more subby. If I were to add another passive crossover, so the wires going to ...
1
vote
0answers
49 views

How to create a Bluetooth audio streamer that receives and transmits at the same time?

I want to create a Bluetooth streamer that wirelessly receives audio from a Bluetooth audio player (like smartphone) and then transmits the received audio to a Bluetooth speaker, with no wired ...
1
vote
1answer
279 views

Dolby HX PRO implementation on existing tape recording deck

I'm experimenting the implementation of Dolby HX PRO's IC into an old stereo Fostex tape deck to improve high frequency and headroom capabilities. HX PRO works as a dynamic processor with the BIAS ...