All Questions
146
questions
0
votes
1
answer
76
views
Mains hum in TDA7265-based active loudspeaker
The old pair of M-Audio Studiophile AV40 active speakers (one box containing all the amplifier parts and the second is just a passive box) I have have developed a clear low-frequency hum. This hum is ...
- 1
0
votes
1
answer
59
views
what is the source of this noise when recording to raspberry pi using USB soundcard
I connect aux out from my laptop to USB soundcard mic in and use arecord to record audio. But I am getting noise even recording at CD quality. The nature of the noise is really strange as it seems to ...
- 376
0
votes
0
answers
69
views
Noise in audio amplifiers when touching the smartphone touchscreen as an audio source
While observing the audio output of my smartphone on the oscilloscope, I noticed a signal being generated when I touch the touchscreen. This signal is around 500Hz and appears in groups of 3 peaks, ...
- 53
2
votes
1
answer
94
views
At a high level, how to design MIDI-controlled audio switching devices for low noise?
I have several use cases for MIDI audio switching. Specifically, MIDI controlled AB pedals and mute pedals. Since these don't really exist, I will need to build my own. (Can you find a MIDI controlled ...
- 357
0
votes
0
answers
47
views
EMF Coupling from microSD writes
Looking for some pointers. I am having an issue with noise coupling into the onboard ADCs while writing to a microSD card. Audio from an pre-amp at 46.875 ksps
I am using a SAMD51 microcontroller (...
2
votes
0
answers
29
views
Why the induced noise is sometimes additive but sometimes works as a constant?
Why sometimes the noise (e.g., induced 50hz hum) is added to a useful signal (thus increasing its 50hz value), but sometimes it works as a noise floor - has a static value and can be overpowered by a ...
1
vote
2
answers
209
views
Trying to record from DIY op-amp results in seldom pops and clicks
I have a 741-based audio amplifier PCB here from the 70s:
When I tried to test it, I powered it with a 24V battery (I tried 12V as well with no difference,) then I shorted pins 15-19, connected the ...
1
vote
0
answers
26
views
Speaker pop / crackle when SBC connects to WiFi
I'm using a Raspberry Pico to detect movement and play a sound via an amp & speaker. At certain intervals the Pico attempts to connect via WiFi to send and receive data.
However, when attempting ...
- 11
0
votes
0
answers
38
views
Audio noise when Bluetooth is connected
I'm making a Bluetooth speaker with a rechargeable Li-po battery. I had some noise coming from the speaker that I suppressed connecting a capacitor at the Bluetooth board's power source. Apparently I'...
- 111
0
votes
1
answer
84
views
USB Audio interface 50Hz + harmonics noise when either laptop or speakers are plugged in
As soon as I plug in either my laptop or my speakers to the wall, I get an unbearable amount of noise in my guitar recording.
Signal chain: Guitar --(1/4 jack)-> Audio Interface --(USB)-> PC --(...
- 103
0
votes
1
answer
79
views
Buck Converter : Light-Load Mode : Efficiency vs Audible Noise Reduction : Portable, Handheld Device
Question
I am designing a portable (handheld, battery-operated) consumer electronic. The limited nature of the power source makes high efficiency critical at all loads, but will a lack of an OOA (out ...
- 437
0
votes
3
answers
172
views
Eliminating Noise from Audio Amp Board Input
I made this project by shajeeb (linked below), and I am having trouble with noisy ground lines. The circuit I made is the same as the diagram below except for where I connect the speaker and amplifier ...
0
votes
2
answers
274
views
Noise issue when powering several audio devices from the same power source
I'm working on my portable music production setup and I'm having noise issues due to connecting all my gear to the same power source.
I have three devices (a sampler, a keyboard/synthesizer and a ...
- 3
2
votes
2
answers
87
views
Hum without ground loop
I have an audio measurement system. The system is connected to and powered by a laptop. The system has no other connection to the AC grid. Now, if the laptop is connected to the AC grid and i measure ...
- 151
0
votes
0
answers
239
views
SIM800L GSM module humming noise
I am trying to play audio over the call by using SIM800l
I am using this "DFPlayer mp3 module" to play audio and connected its AUDIO OUT to the MIC IN of "SIM800L GSM module" and I ...
