Hey Mike4597,
Mix a tube amp with a SS unit for bi-amping & you’re GOING TO HAVE PHASING ISSUES.
OK, before you throw out the baby with the bath water, all you MIGHT need is a few tweaks.
To sweeten up that mid-range, swap out the 12AU7’s in your pre-amp, swap out the stock tubes for · NOS RCA Clear tops.
Interconnects, try the entry level XLO’s, $275/pr (consider used). They’re not forward, but I find the mid-range timbre more transparent.
Bi-wire your speakers. Try Kimber’s entry level wire.
If yea just have to have a new Amp, consider Antique Sound Labs Monsoon (http://www.uptownaudio.com/as/as.htm), or better yet the Canadian company, Coincident Technology (https://coincidentspeaker.com/). Their 211 PUSH PULL DRAGON amp is to kill for. (Consider used).