Just read on Garage 1217 website that they will be offering the Project Horizon with the super-charger option similar to the option for the Project Ember allowing you to use higher filament current tubes like the 6n6p and12bh7. I was very fortunate to receive the 1st one a month ago (special ordered) and have been really enjoying the unit with a 6n6p tube IMO a nice sq improvement over the stock 12au7 more specifically more slam in bass dept I haven't rolled tubes yet will be trying a 12bh7and a 6n2p that excel in my SC Project Ember
I'll report on what I'm hearing
BTW looking forward to their SS amp hopefully soon
Along with Schiit these two USA companies are manufacturing some of the best sounding headphone amps I've heard at ridiculous bargain prices and I have been in this hobby a LONG time and owned or listened just about everything.