OK, I'm here to cap off this mini review of the Tung-Sol 7581A. Though a roller coaster ride prior to being run in, these are well balanced tubes. If there is a frequency range which dominates the other, it may be the midrange though both high & low frequencies are well represented. They are smooth top to bottom. However,my system is very revealing . My speakers are well known for their midrange clarity. And so, I wonder if this hot midrange is as a product of tubes & speakers which display midrange better than most? Also I am a drummer who cherishes bass and eschews midrange. So I may be more midrange sensitive than others. Whatever the case, everything has settled in now and I find no offense. I would recommend these tubes with one caveat...Patience will be rewarded with a good balance of music