from FAQ at nema.com - Is it ok to pull power tubes?
Pulling power tubes will help to decrease the volume a bit, but it's not a dramatic effect. pulling tubes generally results in a rounder, smoother tone with slightly less punch and headroom. you can also expect the amp to compress more quickly. if you're pulling tubes, make sure that the amp is class AB--you can't pull tubes in a class A design, so bear this in mind. also, make sure that you pull either the two outside or the two inside pairs--DO NOT pull the two left or two right.
Your impedance outputs on your amp DOUBLE as a result of pulling a pair of power tubes. therefore, your 4-ohm taps become 8-ohm taps, and your 8-ohm taps become 16-ohm taps.
Mesa's Mitch Faber on pulling tubes (pending)
>Hi Michael,
>Yes, Mitch's 'Insiders Perspective' is not at the Mesa/Boogie website anymore. The half-power/pull tube info was pretty good, and it is a common question asked the Mesa/Boogie Customer Service guys here. We will re-write the tube-pulling information into a FAQ for posting. I'll let you know when this is available.
>Thanks for your interest in Mesa/Boogie!
>-Eric
could look for 1/2 and 1/4 power tricks at Lord Valve's site
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