Just don't expect anything.
I've had a hybrid amp for 20 years, Vincent SV-226MK. Apart from the tube preamp (3x 12AX7), it was just a beefy oldschool AB amp of the chunky kind, oversized transformer and stuff and 2x200W.
Didn't sound any different to the old "my first Sony" amp I had used before, except at ludicrous volume when that one gave up, or the Hypex 252 I have now.
Because the tube stage was properly designed with its only weakness being a tad bit noisy.
That's the thing: tube pre stages can be audibly transparent when done properly, which is what you want - and then there's no point really because a regular transistor stage does the same, only better for cheaper.
If you want audible distortion, go for actual effects units on which you can adjust the level of distortion. That actually makes sense from a playing around and tinkering point of view, but not from a high fidelity one.