Tagged Questions
0
votes
2answers
87 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 ...
-3
votes
0answers
116 views
Coupling a current generator to a very high impedance [closed]
I hacked my renault stock car radio, cause I've lost code. So I decided to enjoy the TDA7560 as a final stage. Actually I made an hack you can see here
It works well, but I have a few doubts. I ...
-6
votes
2answers
133 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 ...
2
votes
1answer
185 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
1answer
119 views
Is a low load resistor a big problem in low pass filter and amplifier circuit
I am going to use AVR's PWM output signal to pass through a low pass filter (maybe plus an amplifier). I found the speaker has a quite low resistance (8 ohms). I tried to simulate my schematic on ...
2
votes
1answer
72 views
How to workaround switch noise
I lately built a 10W amplifier using a TDA2003. I used this circuit (though I removed R4 since I didn't have it, C4 is 50n (two 100n's in series) and R1 is 50Ohm (two 100Ohm's parallel)):
...
3
votes
3answers
279 views
Why has an audio amplifier negative feedback?
Here is a basic 10W audio amplifier - sorry for the European signs:
Why does the amplifier in this application need negative feedback? What would happen if I'd connect pin 2 of IC1 to ground?
0
votes
2answers
110 views
Approx. V, Amps and Transistor required for ~18cm ,12W Speaker Electromagnet
I have a large 8ohm speaker with a "12W500" rating,
and another sticker saying 3/38/5 (QC check?)
~18cm Magnet and 30cm Cone.
I want a silent vibrator for chladni plate (vibrating plate)
-Will it ...
5
votes
4answers
549 views
Can I use a PNP Transistor with an Electret Microphone to get an non-inverting output for my Arduino?
I'm looking to simply read the generic sound level from an Electret Microphone. I've seen a number of schematics with NPN transistors, that will provide an inverted output (~5V when quiet, ~0V when ...
8
votes
6answers
908 views
Paper in oil (PIO) capacitors: what is special?
Many audio circuits use PIO capacitors. What are the electrical Characteristics of PIO caps that make them special (i.e. justify the cost)? Which parts of an amplifier circuit benefit most from the ...
1
vote
2answers
156 views
AC coupling with
I've the following amplifier circuit:
The two BDX77 are actually a single darlington BDX53C (I do not have the spice model for it), and the same for the two BDX78 (a single BDX54C).
It sounds ...
8
votes
3answers
430 views
Audio Amplifier Op amp
I'm trying to design a circuit in which a microcontroller produces a signal and then using an amplifier drives an 8ohm speaker.
I've so far used LM386, but it cannot go above 1W, which turned out to ...
-3
votes
2answers
133 views
Can I safely and efficintly connect a power amplifier to a computer sound card? [closed]
I can't seem to locate any definition in what a "power amplifier" defers from a complete amplifier.
Wikipedia states:
the preamp is not needed other than as a volume control and source selector
...
5
votes
3answers
671 views
Electret Microphone preamplification - will it work for dynamic type microphone?
I'd like to use this diagram to pre-amplify a microphone signal in order to activate the analog input of my arduino
Will it work with a dynamic microphone in place of an electret microphone?
0
votes
1answer
89 views
Audio amp distortion [closed]
I am attempting to repair the amplifier stage of a Harmon kardon 1970's vintage stereo. The right channel is fine but the left exhibits extreme distortion. I fed a sine wave in and can see that the ...
1
vote
1answer
230 views
Maximize performance LM386 and 4Ohm speaker
I'm designing a very simple circuit which contains a microcontroller, an LM386 and a speaker.
I've previously asked a question:Help in designing a speaker driven by an LM386
and the answers helped ...
2
votes
1answer
211 views
Why am I measuring a voltage on the output of an audio amplifier with no input signal?
I am working on a small audio amplifier using an NXP 1W BTL mono amplifier (TDA7052).
I've made a quick test circuit on a breadboard using the typical application schematic provided by the datasheet:
...
0
votes
2answers
709 views
Connecting 5 pin 3.5MM Stereo Jack Socket to TDA2822M
I'm trying to make a portable amplifier based on TDA2822M IC. I've bought several stereo jack sockets but faced the following issue: I don't know the pin-out of ...
1
vote
2answers
171 views
Connecting TDA7052 with a microcontroller
I am planing to use a digital I/O off a micro-controller unit (MCU) and connect it to a TDA7052 input. The TDA7052 datasheet specifies a maximum input voltage of 0.65 V. And since the MCU output bit ...
4
votes
1answer
357 views
Can I use an SMPS to power a audio TDA7293 power amplifier?
I have been gifted a couple of these TDA7293 Power Amplifier boards, and I need to give power to them. Description says
*DC power supply: positive and negative 25-45V
*The power of the transformer: ...
0
votes
1answer
209 views
Testing a 0.3W, 8ohm speaker?
I have a 0.3W (RMS), .8ohm speaker coil + cone that I want to test using various music. However, the 8ohm impedance is lower than typical earbuds (24ohm), and also I can't find headphone jack power ...
2
votes
2answers
568 views
audio amplifier without external battery
I am trying to run a speaker off of my cell phone headphone jack. Currently i have the 0.4 watt speaker (8 ohm) plugged directly into my phone and I am getting audio out. However, i want the speaker ...
6
votes
3answers
1k views
How can one pair of headphones be connected to two audio sources?
I'd like to connect one pair of headphones to the headphone jack on two audio sources simultaneously. I realize I can't just wire two audio sources in parallel since they'll then be driving each ...
5
votes
2answers
2k views
What wattage should a headphone amp be?
I was at a local surplus store today and I got two LM386N ICs. I thought I could make a really simple headphone amp out of these. But I have no idea what the wattage of a normal headphone amp is.
...
6
votes
2answers
158 views
Grounding Shielded Panel-Mount Connectors
I'm building an amplifier in a conductive metal chassis. The general grounding plan is to have an audio ground, a power ground, and a digital ground that converge at a single point on the chassis. ...
2
votes
1answer
215 views
Audio amplifier kills FM radios signal [closed]
I have a Lepai LP-2020A+ audio amplifier and a König FM Pocket Radio.
My problem is that the pocket radio works really well on its own, with the headphone plugged in, but when I connect the radio to ...
1
vote
1answer
166 views
What potentiometer should I use for this phono pre-amp?
Please consider this DIY phono pre-amp.
The text states, that resistors R9 and R22 may be exchanged for potentiometers for gain control.
Since the circuit uses 1.2kΩ resistors for R9 and R22, I ...
0
votes
2answers
297 views
Power Calculation of an Amplifier
Here is a simple audio amp. Is there an easy way to calculate the power it gives?
edit
Resistor value, input level and speaker impedance changed.
2
votes
4answers
772 views
Common Emitter Audio Amplifier
I'm tring to build an audio amplifier. I decided to use a basic common emitter amplifier circuit as a starting point. Here it is:
I have some questions about the circuit.
1-) What transistor can I ...
0
votes
2answers
596 views
Problems in 8W Audio Amplifier using TDA2002
I have made an amplifier using TDA2002 but it's not working properly.
Pot. R1 is not included in mine as it doesn't make a lot of difference and produces noise when I try to adjust the volume.
How ...
3
votes
2answers
467 views
Digital Switching for Audio
I want to be able to digitally switch the input of a line-level preamplifier. I was considering using relays to physically connect or disconnect each source to the input of the amp, which would be ...
1
vote
1answer
523 views
Simple and powerful audio amplifier around BA4558?
I have two BA4558 ICs from an old home stereo. I tested them with simple negative feedback circuit for each channel and with power supply of +/- 6V. The speakers I used are most likely with 8 ohm ...
1
vote
2answers
285 views
Short circuit protection in simple audio current amplifier
In my class, we are to design a current amplifier with short circuit protection.
In our design, we utilized 2 emitter follower amplifiers (Q3, and Q1).
We then added Q4 and Q7 to lighten the current ...
2
votes
3answers
943 views
DIY simple line out converter for “floating ground” car head unit?
On a 25W max power (10V p2p @ 4ohms) balanced (push-pull) high level output factory car audio head unit from which I need to feed a mono amplifier (for subwoofer) that only has an unbalanced line ...
0
votes
1answer
220 views
How do I get 15V from a 34V power supply?
I have an audio amplifier with a regulated power supply putting out around 34V DC. I would like to add a preamp which requires on 15V. How would I draw 15V from the main power supply?
7
votes
5answers
5k views
Simple Audio amplifier Using Transistors
I would like to build a simple audio amplifier using transistors. I know there are IC designs specifically for the task. But i want to use transistors so i can learn how to use them for amplification.
...
2
votes
2answers
207 views
Circuit to exaggerate differences in current
Basically what I am after is some sort of a circuit which will amplify higher voltage signals, but possibly dampen lower voltage signals, in order to make a wider separation between high and low ...
6
votes
3answers
1k views
Audio Amplifier PCB Design Tips
I am going to design a stereo audio amplifier with TDA2030A. This is going to be an amplifier that is going to be powered from 27.6V DC and 12W per channel.
Is there any sources that I can learn PCB ...
1
vote
2answers
396 views
How can I actuate a relay coil from a headphone jack's internal SPDT?
I want to plug my iPod which in turn supplies power to an external audio amp while sending iPod audio signal to same amp.
Is it possible to wire an 1/8" (3.5mm, mini) stereo jack in such a way that ...
4
votes
3answers
576 views
HUGE capacitor recommended in datasheet for Audio Amp
I'm using the TPA3111 audio amplifier in a circuit of mine and I'm working on adding the appropriate capacitors. However, on page 18/19 of the datasheet TI recommends to use a 220mF capacitor on the ...
2
votes
1answer
745 views
Whatever happened to Tripath?
Tripath made some clever digital amplifier ICs in "class-T" as they called it. Seemed to have a better performance than class-D at a comparable price. Went bankrupt in 2007, but I think this had more ...
2
votes
3answers
657 views
Picking a DAC for an audio amplfier
I'm trying to use a specific audio amplifier, TPA3111D1, to power a 10 watt speaker from a microcontroller. I would like to generate sound from a microcontroller that doesn't have a built in DAC, so ...
2
votes
2answers
2k views
Input sound to arduino via microphone jack
I'm designing a gadget which will light up LEDs using a microcontroller. I'd like for it to respond to an audio signal, so I was thinking there are a lot of ways I could do it: If I can accurately ...
3
votes
1answer
234 views
DAC and/or output amplifier selection for a MP3 player?
I am designing my own MP3 player now. While decoding & all digital backend looks straightforward, I am only puzzled with audio output (i.e. DAC->Amplifier part). My goals are 1: sound quality 2: ...
3
votes
1answer
151 views
How can I protect the amplifier behind a headphone jack when interfacing with external circuitry?
I am wanting to mess with the output of my guitar amp. Not actually opening it up, just taking the headphone-output and connecting it to a breadboard and such.
What form of protection, if any, ...
3
votes
1answer
581 views
Testing an Audio Power Amp with Paralleled Transistors
A question concerning my current repair project of an audio amp that uses big (600 W) but otherwise rather classic complementary output stages:
I assume when testing an audio power amp with 6 pairs ...
1
vote
2answers
167 views
Does socket orientation have an effect on sound?
Is it possible that the socket orientation (in Europe: one pin 230V, the other ground) can have an effect (albeit very small) on the amplifier behavior of a very old stereo sound system? What is, if ...
3
votes
2answers
657 views
Piggy-backing off power amplifier outputs
My motor-scooter has a built in radio, with a small speak either side of the front panel, below the handlebars. It's a JonWay, i.e. cheap Chinese, so I suspect the radio is more suited to developing ...
