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1 vote

Confused about how to wire headphone jack with a schematic

The OP, captainretro, reports: "mapplejacks has answered my question in their comment": Yes, the bottom of this circuit should be your ground, which is where the ground pin gets connected ...
1 vote

Confused about how to wire headphone jack with a schematic

Headphones with 3 pin TRS contacts are wired as follows: Tip: Left Ring: Right Sleeve: Ground (or common) for left and right. Thus the Sleeve connects to the arrow at the bottom, the same net where ...
Justme's user avatar
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0 votes
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Noise issue when powering several audio devices from the same power source

I've drawn two devices connected together by an audio cable, and plugged into the same power source (battery on the left). The supply current of Device1 (blue arrows) comes from the battery, flows ...
bobflux's user avatar
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2 votes
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Arduino's impedance in breadboard circuit

When you are overwhelmed with a project, you need to break it into smaller pieces. Test your ADC path with a simpler setup. Play some music and try to capture it directly with the Arduino. You need to ...
Mattman944's user avatar
1 vote
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Do we need to guard the input traces of an audio power amplifier?

Do we need to provide guarding for +IN and -IN on the PCB layout? No, if you were worried about high frequency getting into the input terminals then it would be better to place a high frequency cap ...
Voltage Spike's user avatar
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4 votes

Identifying this coax connector?

That is a Belling Lee aerial coax connector. The female jacks for it are hard to find. For example: https://octopart.com/l1465%2Frpcs-belling+lee-7477530
Davide Andrea's user avatar
0 votes

Unity Gain Buffer Output Impedance

R5 being 10k does not define the output impedance, in fact it has least contribution to it. The volume pot setting will control the output impedance and audio signals come anyway through a 100 ohm ...
Justme's user avatar
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2 votes
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Audio Power Amplifier Layout clarifications

No. Differential impedance is unimportant at audio frequency. Actually this is switching so there will likely be signal at gigher frequencies, maybe 100kHz or so, but still - you don't need to worry ...
danmcb's user avatar
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2 votes

Audio Power Amplifier Layout clarifications

Audio amplifier does not need characteristic impedance traces. The wavelength is about three orders of magnitude longer than any PCB trace would care about. Yes, ampacity around an ampere will ...
Tim Williams's user avatar
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1 vote
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Amplifier chassis noise when not earth grounded

I just solved the problem. There are, which I did not know before, AC/DC power supplies which have the safety earth (FG) connected to V-. The model I am now using is the Mean Well GSM40A18 (Medical ...
linsensuppe0815's user avatar
2 votes
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Sharing ground between circuit and audio input?

If AudioIn+ AudioIn- are line outputs or headphone outputs then yes, you can connect them to this circuit as you described. However, this is a very basic circuit with a lot of issues. It won't handle ...
Mattman944's user avatar
0 votes
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Name and cause for phenomenon in microphone preamp output as seen on scope screen

Finally I found out the reason for this behavior and an easy fix, which has helped to get approximately from 15 to 20 mics working correctly again. The reason is as follows: the mic capsules had been &...
UIR's user avatar
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1 vote

Hum without ground loop

It might be ripple from the PSU and all the internal stuff in the laptop. Have you tried using an external, high quality ADC (like a scarlett audio interface) to capture the audio and see if the ...
DusteD's user avatar
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3 votes
Accepted

Hum without ground loop

Many laptop PSUs, especially if they have unearthed power cables (figure of 8 connector), will have capacitive coupling from the mains onto the DC output, via filter and startup capacitors. This ...
colintd's user avatar
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1 vote

Split and mix audio signals

U10 in the first schematic and U9 in the second schematic are not traditional inverting summing circuits. They are non-inverting summers. This circuit does *not present a virtual GND at the summing ...
AnalogKid's user avatar
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1 vote

Split and mix audio signals

There are different configs possible, You can mix at the input of 3rd opamp or use a 4th and mix at their outputs. There are always trade offs, for high speed its better to load it more but this will ...
acho's user avatar
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1 vote
Accepted

Split and mix audio signals

TL081 seems good for audio management but I'm not an expert TL07x and TL08x are really good and popular for audio applications. But before everything, your VCC is not given, and if it's below 5 VDC ...
Rohat Kılıç's user avatar
1 vote

Split and mix audio signals

The buffers for the other paths are maybe not necessary but not a bad idea, however see my comment below on power supplies. If you use a quad op amp (eg TL074) you have the stages available anyway. ...
danmcb's user avatar
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0 votes

Line-out vs headphone-out impedance

The point is you don't need as low impedance on line out when it is driving a 10kohm input, while the headphone output needs low impedance as it must drive 16 ohm headphones. Also the difference is in ...
Justme's user avatar
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2 votes
Accepted

Line-out vs headphone-out impedance

Both are low impedance outputs, with some differences: For a line out, output current is negligible so it is not a selection criteria for the opamp driving it. In addition, a low value series resistor ...
bobflux's user avatar
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0 votes

Is it possible to add headphones to a Geiger counter circuit?

Sure. The piezo clicker will have a voltage across it (creating the click) which you could process into a digital signal to feed to a micro controller. Your micro controller can then receive the click,...
LordTeddy's user avatar
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1 vote

Random noise in speaker with ESP32+DAC+Amplifier

there are a few steps I would go through here: if you have two boards that have this issue, and you remove D24, does that one NEVER do it, and the other ALWAYS? i.e. is the D24 thing repeatable? if ...
danmcb's user avatar
  • 6,604
2 votes

Amplifier chassis noise when not earth grounded

When you use a floating-DC supply, your device will literally float in the winds of EMI. If you connect more floating devices with the signal lines, then you form a large messy monster with long ...
tobalt's user avatar
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0 votes

What might be killing the output to my amp, with every modification I try to make to my audio circuit?

Your mixing circuit is dropping most of the signal across the 10k resistor, output from mixer is 1k/(10k+1k) = 1/11 of the input signal. I would try increasing the size of the 1k resistor in the ...
user350400's user avatar
1 vote
Accepted

Calculating audio sample output rate for synthesizer

You're conflating several different relevant frequencies, and confusing yourself as a result. First of all, 98.3 MHz is a ridiculously high clock frequency for an audio-output DDS. For music ...
Dave Tweed's user avatar
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0 votes

Calculating audio sample output rate for synthesizer

If you take only the top 12 bits of the phase register, then a 10 bit output is a good match (similar phase error and amplitude error). 98 MHz clocking 10 bit PWM would give you 98 kHz (ish) of output ...
Neil_UK's user avatar
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0 votes

Calculating audio sample output rate for synthesizer

If you have 15 kHz rate for samples then highest frequency you can reproduce, which requires two samples to alternate, really is 7.5 kHz. The fact that PWM is used to output the samples does not ...
Justme's user avatar
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2 votes

Maximum voltage/current on a passive 8 ohm buzzer

12V into 8 ohms is 1.5 amps. That's 18W. Assuming you drive a 0V/12v square wave to speaker, it only sees 18W half the time and 0W for the other half. That's still 9W. No, 12V is not OK if the device ...
Justme's user avatar
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0 votes

Maximum voltage/current on a passive 8 ohm buzzer

12V will fry it. The power dissipated by a constant 12V would be 12²/8 = 18W. Assuming the PWM signal is only on half the time, that's still 9W, way over the rated power of the buzzer.
Simon B's user avatar
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