Use of Philips 7581 in Mk II or Mk III with 105 transformer

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Fiveband

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I've tested both STR 415s and Philips 7581As on a Maximatcher2.

Generally, at 400V the 7581 draws 30% more plate current, and has 20-30% more transconductance than the 6L6.

I've read the 105 transformer runs 500+ volts vs 460 volts for most others.

The 7581 seems to be a very robust tube.

Would substitution of 7581s burn up anything?

Anyone actually tried the swap and/or measured 7581s in circuit using the high voltage power transformer?
 

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