Long time ago, we had issue of BS PSD pitch which shows large noise at high frequency (see elog1642). Today, we found BS PSD pitch noisy again. And this time, the spectrum is as shown in the attached figure 1, which is even worse.

To make sure it is the problem of PSD, I replaced it with another PSD, which has smaller gain. Then the spectrum is as shown in the attached figure 2. As we can see, the pitch spectrum is fine. Therefore, the old BS PSD really has some problems.

I also discussed with Eleonora, she suggested me to buy/make a new one.