The line tracker code was temporarily modified to use SDB2_B1p_PD1_Blended instead of SDB2_B1_PD2_Audio_100k at 13:04 UTC today.

B1p is available even if OMCs are not locked, so hopefully we can monitor the mirror temperature transient when reaching the dark fringe and study the power drop at DF (see logbook #42273 and #42314).
B1p_PD1_Blended is 20kHz sampled, so I had to delete line tracker channels above 10 kHz.
Channels currently available are _FREQ and _AMPL of

V1:PAY_{MIR}_VIOLIN# (MIR=NE,NI,WE,WI, #=1-8)
V1:PAY_BS_BUTTERFLY
V1:PAY_BS_DRUM
V1:PAY_DRUM# (#=1-4; 1 is for NI and 2 is for WI according to VIR-0505A-18)
V1:PAY_9pt6kHz# (#=1-8)

The original B1 version (see logbook #41883) is committed to SVN at revision 74203 and B1p version is committed to SVN at revision 74204.
They are also copied as algo_B1.py and algo_B1p.py in /virgoDev/Automation/PyALP/PySpectral directory for easy swap.