If you don't already have the PJCCS upgrade, I would highly recommend it. Especially if you are running rechargeables. My experience was that they worked almost as long as Alkalines but their voltage dropped off much quicker.
I finally gave up and bought an Agilent 6205C Dual power supply off of eBay for $50. I figured I'd just about spent that much in batteries already. Nothing will be as pure as the batteries, but I'm very happy with the sound when using the power supply. Plus, I still feel like I'm reducing, reusing, and recycling since these things were made back in the 70's and 80's and need a good home.