Where's your bias tonal sweet spot for your power tubes?

Pre Recto days. Boogie modified Fenders, Mark I-IV, Dual Calibers, etc

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GJgo
Mark III
Posts: 248
Joined: Sun Mar 06, 2016 10:38 am
Location: Western Colorado

Where's your bias tonal sweet spot for your power tubes?

Post by GJgo » Sun Apr 01, 2018 11:05 pm

Hey guys,

So I know the whole color code thing for power tubes. I also know that Mesa power sections run on the cold side as designed. I've been thinking about some fine tuning of bias ranges. My question is, for those of you who have put the effort in what bias % do you find in your old Mark amps sounds the sweetest?

Here's what I have in my amps right now-

IIC+ HRG X101 PT- Mesa green 6L6 run ~47% bias.

IIC+ DRG 105 PT- TAD 6L6GCSTR #15 are running 76% in the Class A slots.
...........................TAD 6L6GCSTR #17 are running 28% in the A/B slots.
...........................JJ 6CA7 #33 are running 38% in the class A slots.

IVa- Mesa green 6L6 in all slots is running around 43%.
.......Mesa grey 6L6 running around 66%.
.......JJ 6CA7 #33 are running 15% in the class A slots.

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