Tubes - How close to be a 'matched' pair?

Matched is best these tubes aren't even close!!! What you want to know is the Gm, best would be NOS 14500/14500 and 14500/14500 and above. My understanding is if the sections aren't matched the tubes will vibrate and become noisy at high volumes. I say pass on the tubes your looking at and find a seller that gives you Gm readings and doesn't try to fool or confuse you with with mA only readings!!!!

A third on the "it won't make an audible difference."
Tube matching is critical with auto bias circuitry on the output tubes.If it really isn't a true automatic biasing circuit but rather a one bias fits all. I avoid manual or fixed bias because thats the kind the end user changes Go Figure

No, to me thats not matched, but it shouldn't make a difference. But if you realy do need matched tubes they should be tested at the same operating point as in your amp, and with the same load impedance.

Even if you had tubes that matched perfectly, the in phase and out phase of the phase inverter won't perfectly match.

John C.

For small signal tubes it doesn't matter. I've seen rarely that small signal tubes would operate in Push-Pull mode where the lowest bias current limit is important to match.

Otherwise mostly, small signal tubes operate at their medium output characteristic grid(the most linear and distortion free) that would never touch the lowest or the highest bias current.