Preamp gain choice will depend on the input sensitivity of your power amp, or put another way, on the gain allocation between preamp and amp. I have two systems and use a TVC (transformer volume control) with +6db passive gain on one system, and use an active tube preamp with the system that has Druids. It just happens that I prefer my amps on that system with an active preamp rather than the TVC. I don't use resistor-based passive preamps as that option has never sounded worthwhile to me, though I haven't yet heard the Placette which is commonly cited as an exception to the common maladies of resistance passives.
What you won't want with Druids is a high-gain preamp driving a high-gain (or high input sensitivity) power amp. You'd end up with very little useful rotation in your volume control and your noise floor might not be acceptable. But a high-gain preamp is necessary with a low-(voltage)gain power amp. For instance, the Audiopax 88 monoblocks have only 18db of voltage gain compared to a normal range of 26 - 32 db gain. In such a case, a high-gain preamp is warranted, even on Druids, to be able to drive the amp to full power.
Phil
What you won't want with Druids is a high-gain preamp driving a high-gain (or high input sensitivity) power amp. You'd end up with very little useful rotation in your volume control and your noise floor might not be acceptable. But a high-gain preamp is necessary with a low-(voltage)gain power amp. For instance, the Audiopax 88 monoblocks have only 18db of voltage gain compared to a normal range of 26 - 32 db gain. In such a case, a high-gain preamp is warranted, even on Druids, to be able to drive the amp to full power.
Phil