Although I currently have the BC and Speakers on the same plug I will change that so I can leave the BC on standby to maintain the saved settings, although it does needs the battery changing now.  I will put the Pentas on a remote switch so I can rest the power supply when not being used.   I am working through re-capping and foaming my other Penta set and then in turn this set, to refresh them for another 30 years.  So I want to give them as easy life as possible hence turning them off.  Encouragingly, after 30 years of use the pair I have re-capped showed no signs of significant degradation, the max was 20% variation on the nominal capacitance of some of the capacitors, but no bulging, weeping or heating.  What I have seen though is the mid range L3 coil on the crossover degrading by possibly getting hot, so I have ordered some new ones and will change them too.