No way....there is WAAAAYYYY more punch in high gain. It's not just volume.
I ran mine in high gain. Even with the more volume knob movement in low gain, the music wasn't anywhere nearly as enaging.
Regardless of the gain setting I had, there was hiss with the Tomahawk with UM2s.
I'm thinking it's because that circuit isn't COMPLETELY closed on the TH, I noticed I didn't have the power on yet with my source playing music, and there was still VERY audible music coming through the headphones. Granted it sounded like you were underwater with it being muffled, distorted and blah, but fact was, you could still hear sound.
On my XP, it's DEAD SILENT with UM2s, and there is no sound when the amp isn't on.
In either case, high gain.