hello i thought i give my opinion,and hopefully no gives me hardtime.but with individual bias you can compensate for mismatched tubes.i dont pay extra for matched tubes and my amps sound great.i do try to test them well on my test bench them put in my amps and bias again.works for me .i use cary monoblock amps.most match sets are for fixed bias amps.if you can adjust bias you set the current each tube draws,therefore it balanecs the tubes to a certain extent.
