The power supply does not need to be tweaked. At the flick of a switch you can set the DAC to be powered only by the battery. Yesterday's test was to find out if it makes an audible difference. The previous version of the charging circuit did not allow for charging while listening. That, combined with the smaller battery used in the previous prototype, led to about 6 hours of listening time. That would be fine for most listening sessions, but for long auditions we needed to have both longer battery life, and the ability to run it off the wall, if needed. With the larger battery, the DAC will run for almost a full day (at least 23 hours (no one could remember exactly when we turned it on...)) on the battery alone, or indefinitely, at slightly lower fidelity, with the charge and run setting. FWIW, I could not really hear a difference, but I am pretty ape-eared. Dan and the Pauls could definitely hear it.
