Mismatched power tubes sound?

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.

I lack the words to describe it, but I have experienced the sound of mismatched tubes - one set drawing about 50% more current than the other. Despite biasing, the sound was "odd", less natural, perhaps "phasey" describes it.

Matched Output Tubes, are Mandatory for good results in serious Tube Power Amplifiers. Individual Bias adjustment for each tube is also mandatory to allow the cathode current of each tube to be the same value. This prevents magnetisation of the output transformer. Magnetisation of the output transformer lowers your available Low Frequency Power Output, as the transformer will start to saturate earlier thai if it was not magnetised. The actual Bias Voltage applied to each tube should also be nearly the same. If this differs significantly between tubes, you have a problem with one or more of the tubes, (probably worn out). Despite tube matching by the supplier, tubes still differ somewhat in gain, so some form of AC Drive balance control is of immense benefit. Be aware that tubes wear out, and change their characteristics drastically as they wear. I would discard, or re-match tubes showing as little as 20% difference, 50% are throwaways.