The ratio is a minimum. Ideally you want a minimum of 10:1. Anything over that is fine.
Best,
Erik
Best,
Erik
Impedance matching with tube amp
To clarify, If you go too low in the ratio, say 5:1 you run into the real possibility that the mismatch will cause significantly non-flat frequency response. Sometimes the volume control settings can radically alter the frequency response in minimalist tube preamps with the wrong amp. You can see the effect in many Stereophile reviews like this one: https://www.stereophile.com/content/conrad-johnson-premier-17ls-line-stage-preamplifier-measurements |