I've had good experiences with matching the same brand amp/preamp. In one system I had with matching a McCormack TLC-1 Deluxe along with a McCormack DNA .5 Deluxe the music to me was heavenly. I also really enjoy the music with a Kavent S-33 preamp and P-3300 amp combo. To me I think the Kavent gear is supposed to work together hand in hand. I found the S-33 has a gain control. You can leave the gain as is or decrease it by 10db. From speaking to the dealers that sold Kavent they said the P-3300 has really high gain. I can't imagine the P-3300 without another preamp. I unfortunately didn't try it though. Sometimes it is the little things like that that make me think having the same preamp/amp combo is really supposed to be.
Benefits of brand synergy
How important is brand synergy in matching components? This not only includes amps and preamps but also digital sources from a particular brand, say Arcam or Kell. Is this "synergy" important just for impedance purposes or is there an additional sonic benefit of having everything matching? Thanks.