Digital audio must deliver each block before the next one is needed. Missed deadlines create clicks and dropouts. Not every crackle has the same cause, so first determine whether it follows CPU load, cable movement or loud input peaks.
Crackles usually mean the computer or connection cannot deliver audio data on time, or that the signal is clipping electrically or digitally. The sound of the fault helps separate performance dropouts from overloaded levels.
Buffer underrun
The buffer is too small for the current processing load.
CPU load
Many effects, browser tabs or background tasks can interrupt audio.
Driver issue
Generic drivers may perform worse than the interface manufacturer driver.
USB and power conditions can matter
Unstable hubs, damaged cables and aggressive power saving can interrupt an otherwise capable system. Connect the interface directly when possible and test another USB cable or port before assuming the computer is too slow.
Clipping creates a different kind of harshness
An input that exceeds its available level distorts on strong notes rather than producing random dropouts. Watch meters and reduce input gain before changing computer settings.
Buffer underruns create intermittent clicks
If the processor misses a deadline, the audio stream has a gap. Heavy plugins, background tasks, power-saving modes and buffers that are too small can all increase the risk.
Test the dry path before the full rig
Disable amp models and effects temporarily. If the dry monitored input is stable, add processing back one stage at a time until the crackle returns. This separates a system-load problem from a damaged cable or overloaded input.
Set up the signal path
- Change one variable at a time.
- Use wired headphones.
- Connect the interface directly.
- Keep sample rate consistent.
- Restart the audio app after driver changes.
- Raise the buffer one step and close unnecessary applications.
- Check input, plugin and output meters while playing the loudest part.
When you hear noise, delay or no signal
Crackles appear when moving the cable
That suggests a physical connection rather than processor load. Test another cable and inspect the guitar jack, interface socket and USB connection.