I understand what you are saying Alec, but not all guitar amps have the Line-out/ effects-send facility I have two guitar amps - not too ancient - and neither has this facility.
Why use an extra bit of kit, when it is just possible that perfectly adequate results may be obtained by using the mic input?
As I said before - give it a try

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Willum
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Willum

After silence, that which comes nearest to expressing the inexpressible is Music.
Aldous Huxley
( especially when the music is played on a KN7000....)