I recently added a Veloce Litho series battery powered pre to my Hegel H-30, running as a stereo amp. It sounds fantastic. No impediance issues what so ever, great sound stage, and bit more resolving than my prior tubed pre. When I have it set to input 1, for my computer audio source, a Playback Design DAC 5, even on volume control 1, the lowest output, it sounds relatively loud. My optimal listening level for this pre is now between 10-20. However, when I use it as Cinema bypass for my HT rig, with a new Marantz 8802, I have the volume set to max output on the Marantz, to get reasonable listening levels on the pre set to volume level 30. I did not have these miss matches of sound output/input level challenges on my prior pre.
I appreciate how much more quiet this pre is being battery powered, and the low level resolution, and enhanced bass response. I have not replaced the tubes, and bought this unit used. I found the customer service from Veloce outstanding. They quickly responded to all my questions, even though I was buying a used pre from someone else..and they still operate out of their Philly area plant. so highly recommend this combo.