It's normal for this amp design. The power amp section is very sensitive just like the preamp section. I find it best to just leave the master up all the way. Of course, that's not practical if you want to get preamp distortion at bedroom levels. I've got a VVR circuit from
http://www.skipzcircuits.com/Mini-Watt.html for this amp design. I never ended up installing it though. I found that I basically only use this amp for cleans and run a pedal to get my distortion, which I can easily control with the preamp gain. You want it? Email me @
tresspassor@gmail.com