I owned a BHK preamp for four years and as the OP's amp is SE I would disagree that the BHK is a good choice. The BHK is best matched with a fully balanced amp unless the increased clicking noise from the "unique" volume control with a SE amp doesn't bother you. As I tried it with five different SE amps the problem is not with the connected amps. Also very fussy about needing almost perfectly triode balanced tube sections. The LS-100 from Modwright which I owned before the BHK is a better choice in my opinion for the OP's amp.
Time to upgrade the pre-amp.
I am currently running and ARC SP-16l into an Art Audio PX-25 power amp which feeds a pair of Blumenhofer Genuin FS2s (94db). I listen to mostly vinyl atm, and I have an external phono stage (Icon PS1 mkii). I think at this point, the pre-amp is the weak link.
Although I am not wedded to buying another ARC preamp, I am leaning in that direction due to company reputation, longevity, accessibility of local dealers (Northern NJ) and resale value, though I am definitely looking for that full mid-range and "musicality" typically associated with all tube architectures.
I have an opportunity to buy an SP-11 for $4,000, and from what I am seeing, if I wait, I may be able to get an SP-10 in that same range. However, for ~$2,000 more, I could likely get a Ref 5SE, which would be the top of the budget, but has in addition to any sonic advantages, a remote and tube hour tracker.
My questions are: (1) is it worth holding out for the newer Ref series (~10 yrs old at this point) vs the SP10/11 which are 40 years old at this point; and (2) if it comes between the SP10 and SP11, What I have read here is that the SP10 is all tube, but while that unit’s phono stage is particularly strong, the rest of the line inputs are not up to the SP-11. If it turns out that they are close, I would likely choose the SP10 between those two.
Very interested in how folks think about this.