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

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-2
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1answer
35 views

Micro audio preamp with low consumption

The audio output for all of my devices/computers is too small to push my speakers to the maximum (or at least at 50%). I want to build a very very small audio preamplifier to hook between the ...
0
votes
0answers
22 views

DC 10V 1.4A input, 12VDC 1A power adapter [duplicate]

I have a device requiring DC 10V 1.4A input and a power adapter that fits, but is 12VDC 1A. Is it safe to use? I looked at a few of the discussion boards on this site, and others, and couldn't really ...
0
votes
0answers
39 views

Driving a 60W 28Khz Ultrasonic Transducer

I am trying to find a circuit diagram to drive a 28Khz 60W ultrasonic transducer. Preferably, it would be DC run and be able to power the transducer at full power for at least 5 to 10 seconds as a ...
2
votes
2answers
113 views
+100

Analog preprocessing circuit (anti-alias/pre-amp) for driving ADC

Background Similarly to what Jeri Ellsworth did in her C64 Bass Guitar hack I am working on an audio-to-midi converter for my bass guitar. I am also planning to use piezo discs as sensors placed ...
0
votes
1answer
74 views

wiring from car amplifier to leds syncing to bass

I have 12 V batteries, 2 1500-watt amps and 2 Ω each, and 2 subwoofers at 2 Ω each. I was planning on buying 4 blue 12 V led light strips that run at about 100mA each. I would like it to brighten/dim ...
0
votes
0answers
41 views

Eliminating click/pop from analog switches

I have completed my first working prototype for a digitally controlled FX loop and, while it is quite well (no significant signal loss, fast switching etc.), I still have a nagging issue with it: the ...
0
votes
2answers
67 views

A Question on Resistance

A 19 v dc supply is switched to an IC amplifier. A 12 V dc, 100mA pilot lamp,(nonLED)is wired in parallel with the switch to indicate an active circuit. What size resistor is needed to support the ...
0
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0answers
33 views

Car battery recharge time and audio amplifier

I want to build an audio amplifier for a speaker, that will be placed in a car. And I am unsure about what is the maximum power output of an amplifier that can be used. I have a 4\$\Omega\$ speaker ...
1
vote
2answers
44 views

5-12v ~15w simple class a audio amp & build to 2.1 pc speaker

is there any IC that take 5-12v input and 15 w output class A amplifier for 2.1 ch pc speaker?(can be mono amp) because i've search google and found ic that only take more than 15v DC power supply, ...
2
votes
2answers
219 views

Capacitor/resistor effect on audio signal

I have a pair of 20 years old electrostatic speakers that have an analog first order high-pass filter before the electrostatic panels, so there is a capacitor in the audio signal path. The original ...
0
votes
1answer
25 views

How to change component values when changing tube B+ voltage

I'm starting a build a tube headphone amp from diyaudioprojects.com (the simple one: http://diyaudioprojects.com/Solid/12AU7-IRF510-LM317-Headamp/) The projects uses a 12V supply for the tube plate ...
0
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0answers
38 views

Design a low-pass RC circuit to eliminate SMPS noise

As per a previous question I've asked - trying to track noise from a circuit. I've built a audio relay switch and the audio path seems to be inducting noise from the relay power supply (shared ...
0
votes
1answer
66 views

Clean DC power supply from a dirty souce

I'm building a guitar pedal which uses a series of relays to switch various signals. The relays are currently being powered by a cheap 5V switchmode supply and the audio path is inducting high ...
-2
votes
1answer
65 views

Is this a true pink noise generator?

I found this neat circuit (page 18/62) but I don't understand it. This doesn't seem to be your usual white noise generator plus pink -3db/octave filter. Is this a true pink noise generator?
1
vote
1answer
182 views

What is the purpose of the capacitor in this transformer circuit?

I a audio DAC output stage I have seen the following circuit. It's function is to convert an balanced signal to an unbalanced signal. IN+ and IN- are differential outputs that are biased at 2.5V. ...
0
votes
1answer
42 views

Breadboarding digital mixer: deriving Vref from Vdda, and capacitor between Vdda and Vssa?

I am assembling a digital audio mixer from an old IC I have on my workbench. And I am reading the data sheet and trying to make sense of a note that describes the Vref pin (reference voltage). The ...
1
vote
1answer
102 views

Stereo heaphone doesn't work properly when the balance is centered [closed]

I have an old headphone (Philips SHP1900) and it used to work fine, until the day which I accidentally stepped on it... Since then, when I listen to music, the instruments sound really loud and the ...
0
votes
1answer
63 views

All capacitors leaking on Emotiva PSU? [closed]

I've just opened the top of my XPA-2 amplifier and had a huge surprise: it seems like almost ALL of the caps are leaking from the bottom. Not just the main PSU caps, but smaller ones on PSU PCB and ...
1
vote
1answer
57 views

Limiting small signals to one direction (ideally with passive components)

My setup is as following: I use a Y-Cable for splitting an audio signal to two devices (boxes and earphones). The headphones have quite big speakers so they act also like a microphone - feeding back ...
-3
votes
1answer
29 views

how to connection of audio jack of headphone [closed]

My headphone jack has broken. There are 3 wires green, blue and red with green strip... Which one will be the ground wire and which one will be speaker wire.(left & right).?? And how to test it ...
0
votes
0answers
23 views

Hum/buzz noise in audio system

I have crazy experiment about hum noise problem. I have ferrite transformer to eliminate noise from hum noise , not succeed ,than i use metal E-I transformer ,there is no hum in system. I could not ...
1
vote
1answer
87 views

Use a headphone jack to activate a 'silent' speaker

I am looking for a type of speaker (around the size of a coin) that connects to an iPod which plays silent tones or pulses. Like a miniature speaker that a person can hold and feel the sound signal. ...
1
vote
0answers
29 views

Protecting opamps from back-EMF, necessary or common in 70/100V audio?

Clayton and Winder's opamp book 5th ed. p. 283 briefly discusses the use of Zener diodes to clamp (as a TVS) voltage spikes from inductive loads from taking the opamp's output stage above its power ...
0
votes
1answer
62 views

Looking for an efficient audio amp circuit

It seems like all the circuits that I find are using outdated and inefficient technology that requires massive heat-sinks at anything beyond headphone levels. Is there any particular reason that there ...
2
votes
2answers
66 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
vote
1answer
42 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
vote
2answers
68 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
73 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
54 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
votes
1answer
39 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
votes
3answers
122 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
43 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
2answers
91 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
vote
2answers
83 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
votes
0answers
54 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
votes
3answers
95 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
81 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
71 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 ...
1
vote
1answer
123 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
127 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
36 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
175 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
97 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
72 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
135 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
73 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
58 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
64 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
184 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
45 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 ...