I'd give the VdH a little time even if the character of these different units is "baked in" to the design. I've had an Allnic H-3000 for quite a while and recall that it took some time to come on song. As @wrm57 mentions, rolling the rectifier makes a significant difference in the unit ---I've tried several and for the voicing of my system, like the old GEC u-52.
How Soon Do You Realize You Don't Like a Piece of Gear?
I've been running all Allnic H3000 for a bit and love it. I decided to try a solid state transimpedance phono, The Grail by Van Den Hul and am coming out unconvinced of the change. The VDH has only been powered on for 24 hours and not fully broken in yet, which is estimated to be around 50-100 "listening hours".
I don't hate the VDH, but am curious if it's going to grow on me or not. It has the detail, silence and linearity in spades, but my Allnic has the gravity, lushness, depth and ethereal timber I've grown to absolutely love. How soon until I should cut my losses and move back the Allnic and what are your thoughts on break-in time and waiting it out?