LDR Active Preamp - does it exist?

The battery is not a significant improvement. There is a difference in the sound but I cannot precisely pinpoint what it is. I swap the power supplies around every so often, but could live with either one.

Same as what Clio09 said, very hard to pick the difference between battery and wall wart.
Even the highly critical listener/reviewer Sam Tellig of Stereophile has memory lapses to what he has on powering his Lightspeed Attenuator when he's using it, as he has both battery and wall wart, and has to look to see which one he last put on, they are so close, same with his guitar teacher son and his Lightspeed I believe.

Cheers George

I've had both a battery and an AC version of the Lighter Note, which is based on George's design, at the same time. I found that the AC version is better but only if you keep it on all the time. I don't know why, but it sounds better after being on for 48+ hours. I've confirmed this a number of times and also in two different homes. The AC version has better dynamics and more sparkle up top than the battery version does.