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

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0
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0answers
18 views

Short period of noise after audio stops?

I am building an audio amp based on the TPA1517. I added a bluetooth module to it and I noticed that now wired or bluetooth, once the music is paused, there is a few seconds of noise, a pop, and then ...
0
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0answers
24 views

Reference: audio engineering I2S [on hold]

I want to build a portable music player with DSD support. My idea is to use a raspberry pi and build a dac board based on some dac chip which shares the dsd and i2s port. Beside the datasheets, what ...
2
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1answer
160 views

“Stopping” sound after a certain frequency

A friend has a condition that can cause seizures when listening to frequencies over 1500Hz. To help her out I made a passive first order (RC) low pass filter with a cut-off frequency at ~1300Hz but ...
0
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1answer
33 views

generating a 10mVpp signal from computer

I have an input to a system that requires a 10mVpp max signal. I have to use my computer to input it due to constraints out of my control. I am well aware an audio card cannot go down that low. I ...
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3answers
45 views

Signal loss over distance

What diameter size copper wire is needed to send 30KHz audio at 50 watts over to high power tweeters 120 feet away without losing too much signal over the wire?
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2answers
50 views

Impedance matching for piezo element

I am trying to boost audio signal from around 3V to around 60V for a piezo element with a component as small as possible. I found audio transformer MET-23 that reflects 1.6 kOhm impedance on primary ...
0
votes
1answer
63 views

What resisters for inverting op-amp should I use?

I am not an electrical engineer by any means so go easy on me here. I am simply experimenting with a speaker amplifier. My situation: I have a Clarion xc1410 4-channel amplifier with a 10k input ...
-3
votes
1answer
37 views

Solder old Home-Cinema wire to Audio Jack Plug [closed]

So I have this ancient Home-Cinema (Panasonic SA-HT540) and the main unit appears to be broken. The speakers should work just fine though. I'm planning to solder the speaker-wire (which is a simple ...
0
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1answer
36 views

Audio Amplifier Design (CE Amplifier - Class AB Power Amplifier)

I am trying to design a Audio Amplifier which provides a gain of 20db (10V/V). I have managed to design the following circuit but the output voltage gets clipped and clamped. Please find the schematic ...
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2answers
33 views

CE Amplifier Design for Audio Amplifier

I am trying to design an audio amplifier which provides a maximum gain of 20dB (or) 10V/V . For the circuit I designed the lower half of the amplified signal is being clipped. I am also attaching the ...
-2
votes
1answer
52 views

Why Can't I get a Smooth Sine Curve in PSPICE

I am trying to simulate a Volume Control Circuit in PSPice Student Edition. I am unable to see a smooth sine curve at the output. Could you check my circuit. Find the Schematic below Thanks
3
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1answer
53 views

AM335x FPGA Memory Integration

I'm currently designing a digital mixing console. We have a somewhat large number of ADCs and DACs (more than the multi channel audio serial port on the processor can handle). We decided the solution ...
0
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2answers
53 views

Connecting and soldering audio cable of several earbuds, but none is working

I have about 10 sets of earbuds accumulated over the years, where just one of the two is working or the jack is broken, so I thought to try to fix them. I've tried mixing several of them, in example ...
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2answers
51 views

Op-Amp decreasing amplitude of audio signal

For a final project for an electrical engineering course I am taking (my first), we have been tasked with combining input from a small microphone and an aux cord, amplifying it, transmitting it via a ...
0
votes
1answer
29 views

Modifying Voltage Controled Amplifier to become attenuator [duplicate]

https://www.fairchildsemi.com/application-notes/AN/AN-6603.pdf Page 3 top left of this also shown in this screenshot: http://i.imgur.com/rp3lYsl.png How would you modify Figure 11 to make a voltage ...
0
votes
2answers
51 views

Is there a circuit that amplifies current or voltage relative to signal frequency?

I am trying to create a circuit that outputs a higher voltage/current as the frequency of the signal input (such as an audio input) gets higher - such as to allow all frequencies to bypass a capacitor ...
0
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0answers
25 views

Floating Ground Adapter for Car audio line level signal?

I have a an Audi that uses the Bose external amplifier. Bose/Audi designed the system to use a single common between the head unit line out and the Bose amplifier line input, so it is four wires (FR+, ...
0
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0answers
43 views

vhdl code to do ramp-up & ramp-down for audio

I'm trying to learn more about VHDL and audio. I generated sine wave data using matlab. I want to generate three different type of audio output so I thought of doing ramp up and ramp down for my ...
6
votes
3answers
530 views

Audio transformer: What to do with an unused winding?

For the purpose of impedance matching and floating a single-ended, ground-referenced signal, I am planning to use an audio transformer like this one. Here's the schematic from the data sheet: My ...
0
votes
4answers
56 views

Can I efficiently monitor sound card line in with a vu meter?

I'm trying to monitor some audio input to my desktop pc with a vu meter. I've connected to the line in, and it's just a bog standard on-the-motherboard sound card. I'm having a problem understanding ...
0
votes
4answers
73 views

Audio transformer for 12V light emitting circuit

I'm working on transmitting audio through light using amplitude modulation of an LED, received by a solar panel connected directly to an active speaker. Something like this: simulate this ...
1
vote
2answers
52 views

Using a LM311n in a class D amplifier as comparator

I'm making a class D amplifier as a school project, and we are currently at a stage where we simply need to add the comparator. But the comparator (LM311n) does not seem to run as intended. My ...
0
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2answers
38 views

How to increase speaker max input power

I have a tiny 8 ohm speaker rated to accept a maximum of 0.5W. The docs explicitly say adding 1.5W or more will "blow it out". However, I'd like to use this speaker with a 1.5W amplifier (PAM8302A). ...
2
votes
1answer
58 views

How to increase an output of opamp in this noise generator?

I'm working on a noise generator for my analog synthesizer and have problems with current design I built. As a noise source I use NPN-transistor in avalanche mode with only base and emitter connected. ...
2
votes
1answer
45 views

Variable Input Voltage Power Measurement

I've looked around the site for suggestions, but think this question is a unique one and would love some conversation. I need a method to measure the average power in to a transducer. This method ...
0
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2answers
74 views

XLR to Microphone wiring

I have an XLR cable that I am trying to wire directly to a microphone that did have a Micro XLR connected to it. I have cut the male micro XLR's from each side and am left with the following wires - ...
1
vote
2answers
32 views

Audio Mixer Passive Attenuator Circuit

I'm currently designing a digital audio mixer. One common thing found on audio mixers is a optional 20dB pad on the input. I've seen some attenuator circuits but all of them require you to know your ...
2
votes
1answer
79 views

Missing low frequency tones from bluetooth audio output

Currently I'm working on a project which uses a bluetooth module (Bluegiga WT32i) to get audiostreams from my iphone to a 3.5mm stereo jack input for a car AUX input. The problem now is that I have ...
0
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0answers
17 views

How to use switch in line-in audio jack connector to (de)activate electret microphone?

I have a megaphone with an electret microphone. The voltage at the microphone is about 3.1V and the microphone has a resistance of about 1 kOhm: I replaced this microphone with a little circuit to ...
0
votes
1answer
43 views

enclosure fabrication resources for the upscale hobbysist [closed]

I recently saw a beautifully made 1RU 8Ch microphone pre-amp that was in a beautiful enclosure with a very pro looking faceplate and so on. The engineer wouldn't share who made it for semi-obvious ...
0
votes
1answer
61 views

How do I get rid of speaker static?

I made the basic TPA1517 circuit as shown on page 11 of the datasheet. When there is nothing plugged into the input, there is a lot of static. When I do plug something in, there is less static, but it ...
1
vote
1answer
26 views

Add line in to electret microphone and mute the microphone when plug is connected

I have a megaphone with an electret microphone. I want to modify the megaphone so that I can optionally conntect a notebook's headphone out to the megaphone. So I want to add a line in connector to ...
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0answers
36 views

How does a cascode or beta-enhanced voltage amplification stage work?

I'm studying electrical engineering and we just finished a project where we had to build a power amplifier. But I think I can do better than what we did. I read Distortion In Power Amplifiers where ...
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0answers
5 views

How do I connect old surround sound to new PC? [migrated]

How can I connect my old 5.1, HiFi surround sound system (with them AV audio connectors [red and white]) to my new PC (with 3.5mm audio ports) so that the full 5.1 surround sound will work? I have ...
-1
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0answers
31 views

OPAx134 Inverting Amplfier

simulate this circuit – Schematic created using CircuitLab I'm current designing a digital mixer and need some advice on the analog side of the ADC. We are using a PCM4201 for our ADC. ...
0
votes
5answers
41 views

Impedance and frequency response

Was reading the following: "In order to deliver its full frequency response, a ribbon microphone needs to see an input impedance of at least 4-5 times its output impedance. For example, if a ...
1
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2answers
43 views

Understanding this circuit for getting sensor data from an arduino to a phone via the headphone jack

I am trying to understand the circuit below which relates to getting sensor data from an arduino to a phone via the headphone jack. The instructions on this page aren't clear on what the function of ...
3
votes
3answers
76 views

The talk of current amplifier vs voltage in audio?

I cannot find any good scientific basis for the supposed benefit of designing low wattage current source amplifiers in lieu of the traditional voltage amplifier to drive a loud speaker. Given, this ...
0
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1answer
33 views

FreeDSP (ADAU1701) isn't working - what is the issue?

I had FreeDSP PCB soldered recently and for the last two days I've been struggling to make it work. FreeDSP basically consists of ADAU1701 DSP, 24LC256 EEPROM, 12 MHz oscillator, IO circuits and ...
-2
votes
1answer
68 views

10K Audio Passive Summing circuit

Several questions: Radio Design Labs makes a 10K combiner/divider that sums or divides line level inputs/outputs. Why is 10K a useful resistance to achieve this as opposed to something else? The spec ...
0
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2answers
60 views

Performance of Parallel vs Serial speaker wiring [closed]

Are there any sonic differences or performance characteristics of wiring speakers in serial vs parallel? I'm assuming in either instance one is properly loading the amplifier and has the choice of a ...
-2
votes
1answer
45 views

Pic microcontroller voice recording and playback [closed]

I was wondering we can easily interface LCD, led an pot etc but I couldn't find way how to record my different voice strings and playback specific string as per commands that given to pic
0
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2answers
67 views

Am I using IR2104 correctly?

simulate this circuit – Schematic created using CircuitLab I am using the following circuit with given component values. I am not getting a proper level of output from Ho or Lo pin to ...
0
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0answers
35 views

voltage drop when probing a NPN transistor's emitter to collector, collector to emitter for PNP

I have some old 2SD1785 and 2SB1258, NPN and PNP transistors that I pulled off of a car audio amplifier. Using this site, I tested the transistors in question and find that they fail on the test on ...
0
votes
1answer
63 views

Microphone on Arduino for Sound Detection

I'm working on a design to have a microphone on Arduino board for sound detection (clapping sound etc). I see there are lot of circuits floating on internet but almost everyone has an output to ADC ...
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0answers
39 views

Wiring 2 audio output transfomer secondaries in series or parallel

I want to know if wiring 2 audio output secondaries in series is doable. See problems with this schem? Would parallel be a viable alternative?
0
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2answers
43 views

What is a good capacitance to use for a low pass and high pass filter?

First, I am using the minimum components circuit for the LM386 I am going to use the first circuit on this page. I am going to use a potentiometer in series with the circuit to give me variable ...
0
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1answer
39 views

How to lower volume on microphone input before outputting through headphones? (Using a DSP) [closed]

As part of a senior engineering course, my partner and I decided on tackling the problem of hearing loss in youth, and went with a more preventative approach, trying to reduce the amount of cases ...
0
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1answer
73 views

Making a [4-Pole TRRS to 3.5mm Stereo & Mic Adapter (Male to 2x Female)] from an iphone headphone splitter jack?

I want an adapter that merges the microphone and earphone 3.5 mm jacks into a single 3.5 mm jack ( basically I want to build the blue adapter thingy): I have an earphone splitter for iphones that ...
1
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0answers
55 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 ...