From the beginning I have been using the ART Tube V3 and the Art Tube Project studio preamps for phantom power and additional gain when needed. I have not seen much difference in the sound unless I drive the tube pretty hard. But I have often wondered if there might be some sound quality improvement with a better preamp. At the same there is not way to bypass the preamps of the 428 other than to turn them down. It is not that I am getting a bad signal from the 428 even when going directly in without the ART preamps. Actually I get enough gain already with very little noise. Any US428 users still out there that have found much benefit with a more expensive preamp like the Warm Audio WA12?
