The common mode board for the ALS cavity locking, S/N S1102637, has been modified to account for the fact that the green cavity pole is expected to be around 600Hz for the one arm mirrors we have (up from 200 Hz). The common compensation is now a 40Hz/600Hz pole/zero pair. We also modified the first boost filter, so it can be engaged. It is a 100Hz/1kHz pole/zero pair. In detail:
C121 -> 220u (from 33n)
R69 -> 18.0k (from 120k)
C118 -> 1u (from 100n)
R77 -> 165 (from 82)
We left R70 at 1.2k which reduces the HF gain by 7%.