good luck with that Dr
When I first got into tube amps my APT H was my last SS pre to sell,as well as my Pioneer Spec 1 I held onto.When I got full swing into tube amps it was with Dynaco st70's/MKiv monos and MK iii mono's then used Dynaco Pas2/3's.Put my Apt H on the back bench,eventually sold.
My Fisher 400c and Scott lc-21 preamps are my go to now adays and better anything SS I ever owned.
My tech buddy runs Eico HF 85 and HK citation 1 preamps...we have ton's of listening experience with these and would never go back to SS pre's
Im hopeing the front end on the HF-20 is as good as the HF-85 pre..
hunter