Hello,
We purchased a TAS5508-5124K7EVM evaluation board that outputs an annoying disturbance on the audio output.
Our system consists in a pair of tweeters and a woofer connected to J101, J103 and J105 respectively. We filter the signals through the DSP DAP channels 1, 2 and 3. Our filter design is based on 96kHz of sampling frequency.
The two files attached are two configs: REV_A (built based on the original init.cfg) works well concerning the filtering, but the volume does not work; REV_B (built from scratch) fixed the volume issue but it is also altering the final audio frequency response.
The disturbance is a sort of harmonic signal, sometimes really distorted (chirp), which depends on the sampling frequency (manually set on the USB eval board): starting from 96kHz the disturbance is higher, then switching to 48kHz simply modulates the noise.
We shot a little video of our setup and the disturbance's behavior, here it is the link:
https://goo.gl/photos/FT8ETM7o7s2uGJVHA
https://goo.gl/photos/FT8ETM7o7s2uGJVHA
Moreover, the disturbance does not have a predictable behavior. Sometimes it acts like the video above, other times it produces a frequency sweep (firstly we thought to a parasitic capacitance). Other times, on the other hand, the system works fine for just a dozen of seconds.
We tried all the analog and optical input stages, without any changes. We tried also different PSUs (both switching and linear) either connecting the board to GND nor without any other connection.
Finally we purchased another eval board, thinking that the previous one was bugged. The problem still remains.
We would like to go deeper in the details of this issue as soon as possible. Thank you for your consideration.
digital_habits_revA.cfgRev A
digital_habits_revB.cfgRev B
digital_habits_revA.cfgRev A
digital_habits_revB.cfgRev B