Just want to add that the LLP is a very high quality power supply which provide linearly regulated, ripple free DC to the LISA. When one plug in an external power supply, it will take over the battery power. If the external PSU provides "dirty DC" the sonic quality suffers as a result. Of course, one can also run the amp on battery for the best result, but if you are like me who will be using the LISA as a desktop amp, the LLP comes in handy. Besides, it will also be able to provide slight more juice than the built-in batteries, and I believe this is only beneficial to what we hear.
I'm just trying to get a justification for LLP. Because if it doesn't really improve much of the sound quality then, I personally don't think it's worth my USD$500.- I'm currently using LISA Expedition which I should technically get over 50hrs before a recharge required, and I think, it's sufficient enough without LLP to run the Amp all day. I store my LISA in a charger bank before going to bed everyday. Therefore, I don't find LLP suit my purposes or handy.
Also does the voltage adjustable? or it's fixed at 24V output? How about the plugs? Does it come with many different sizes?