Break in period for tube amp. How long?


Can you please share your experience on break in time and initial sound of new tube amps. Mine are sounding awful out of the box (NAGRA VPA).
jjwa
power tubes should be allowed about 100 hours - but "awful"? it shouldn't be THAT bad.
I would recommend letting then run at least 100 hours before doing any series listening..They will probably even improve a little more after about 150 to 200 hours or more.. I would run CD player ect. on repeat at low volume levels and let run a few days straight to break in a little quicker..
Good luck,
Dave
Musicslug is correct, they should not sound aweful though, i would check other possiblities out that can cause this possibly..
Dave