There are a number of things you can do for the Dude preamp. My friend has one and he did a few things. Upgrade the 6SN7 tubes to Shuguang CV-181 tubes, upgrade the volume control to a KHOZMO ACOUSTICS volume control, change the output caps to either V-Cap Oil or V-Cap copper I think the size is .47uF. Also I can build you a hybrid power amp for your price with point-to-point wiring. Think old Counterpoint SA-220 / NPS power amps without the reliability issues and better parts.
Happy Listening.
Happy Listening.