Graham you have a battery powered phono amp don't you? Do you like it?
Yes. I have a couple. One is a very simple circuit that runs of 3 x 9V batteries. I draws very little current and the batteries
last for months. I also have the same unit that has a much modified circuit and that has 10 x SLA batteries.
Even the simple one sounds great. The simple one is easy and cheap to build the dearest part was the batteries. I can get
the details to you if you want to build it.