Passives are some folks taste but right now for a bang for buck pre I'd say the Modwright 9 used or maybe better Dodd Battery power.Real no frills but off power the grid.Friend has one and loves it.If you want old school tried and tested an Audible Illusions Modulus 3A.Think tubes in pre section can sound good at reasonable prices though if budget was higher lot's of SS designs come in.But you have some pretty high end valve amps so maybe SS design.Haven't heard passives that have the bass or dynamics an active pre has.But for those amps I (and I am sure you) wish you had an 5 times budget to open it up to CAT,Lamm etc and other top end pre's.
Chazz
Chazz
Chazz
Chazz