With the Decware I have tried, I haven't experienced a pre increasing volume appreciably except if the source puts out pretty low voltage. Then the extra voltage hit from the pre seems to matter. With different Decware amps up to the Torii in wattage, I have tried to get more volume with a ZStage and CSP3, but have not heard a notable increase in overall volume before amp distortion. In my experience anyway, at some point of raising the CSP3 gain, the amp needs to be decreased to avoid distortion, and as best I can tell, the relative volume is pretty close to where the amp would distort on its own.

Hopefully others will comment on Steve's modifications. Mine probably relate in ways though. For them, Steve's original design choices were my reference, and though modifications could be used to more seriously adjust weight, that was not a goal for me. It was more about trying to more-or-less keep the original signature while increasing finer resolution, space, and speed/dynamics in musical ways... I would say increased resolution does increase density though, with more speed, contributing to the quality of weight.

Thanks CAJames for your explanation of how volume works. My experience has been like you describe, where voltage balancing variations between source, pre stages and amps are more about sonic character changes than volume. And though some effects from how those gains/voltages balance can perhaps change the sense of volume some, they didn't seem to effect the real volume in notable ways in my setups.