Obviously I'm not seeing the BAT material, but BAT has to be addressing the OUTPUT tubes, not the frontend tubes. Various versions of the 6SN7 are rated for higher Voltages than others, but I've never seen an audio-equipment manufacturer write anything like that about 'N7s.
Buy what you want to hear and don't worry about your 'N7s' Voltage ratings.
FWIW, my favorite 'N7 is the Tung-Sol RoundPlate, and 2nd is the Ken-Rad. Both are slightly warmly balanced, NOT bright but have high-quality treble, and more spacious than the average 'N7. To my ears, the TS-RP is slightly more-spacious sounding than the KR, so of course I spend $150 for them instead of $40 for the KRs. No one ever said we audiofools were logical.
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Buy what you want to hear and don't worry about your 'N7s' Voltage ratings.
FWIW, my favorite 'N7 is the Tung-Sol RoundPlate, and 2nd is the Ken-Rad. Both are slightly warmly balanced, NOT bright but have high-quality treble, and more spacious than the average 'N7. To my ears, the TS-RP is slightly more-spacious sounding than the KR, so of course I spend $150 for them instead of $40 for the KRs. No one ever said we audiofools were logical.
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