@keoliphant
At lower volumes Harbeth is a great choice even with SS. ATC are bone crunching dynamic at louder SPL with SS but at lower volumes (if that is mostly what you are after for an office) then I would advise a warm traditional style tube preamp to warm them up but definitely SS power amp to drive them. KEF is similar to ATC - fairly neutral. Harbeth sound really good at low volume - they have almost a tube warmth to them in the bass (so not the last word in bass but great for casual listening at lower volume - think BBC classical radio all day )
I am not familiar with how warm the BHK preamp sounds. I see both BHK pre and monos are MOSFET output which will have no problem with ATC but probably won’t be as warm as a conventional tube amp with autotransformer.
At lower volumes Harbeth is a great choice even with SS. ATC are bone crunching dynamic at louder SPL with SS but at lower volumes (if that is mostly what you are after for an office) then I would advise a warm traditional style tube preamp to warm them up but definitely SS power amp to drive them. KEF is similar to ATC - fairly neutral. Harbeth sound really good at low volume - they have almost a tube warmth to them in the bass (so not the last word in bass but great for casual listening at lower volume - think BBC classical radio all day )
I am not familiar with how warm the BHK preamp sounds. I see both BHK pre and monos are MOSFET output which will have no problem with ATC but probably won’t be as warm as a conventional tube amp with autotransformer.