Yes, the dB switch was out and the Discman I was using was a little shy on juice going to the pre.
Hooked into my system, headphone volume was greater than with the Discman but still not as loud as I thought it should be. It has been a long time since I listened with headphones and the last amp I plugged them into was a Kenwood Model 600 and it seemed that it would make my ears ring for most of the next day.
Since the other pre (NAD Monitor 1000) was still in service, I also tried headphones into it and there was little difference in volume between it and the 3300 II so it seems all is good.
Something I've always wanted to do here at home was a fast A/B comparison between pre-amps so I did that using a phono switcher. Switching between the NAD and PL during different portions of a single vinyl track made me conclude that I like the PL better. There didn't appear to be a significant difference in the bass area but vocals and mid/high range instruments sounded more distinct through the PL. When I get my Hafler DH-101 finished, I'm going to make the same comparison.
Could be my prejudice about op-amps is unfounded.