Hello
Why do I use "GNURADIO" to generate a 40khz sine wave, and there is no signal after reaching 23khz?
I have reference to this article for exclusion
But he still can't solve my problem
Does the hifiberry dac2 need to open something else to output the frequency over 23KHZ?
Your software probably is using 48kHz sample rate. This would limit the frequency range to 24kHz. You probably just need to select a higher sample rate. Check the manual pages of the software you're using how to do this.
Also make sure, you don't have stuff like PulseAudio running that resamples to a fixed sample rate.
Thanks for your answer, I have found the problem, my sampling frequency is set too high, which will force the frequency down.