No Bias Needed for 18watt Mojotone TMB?

[smithguitars]

Please help me grasp I thought all amps needed to be biased, or maybe I am showing my (bias) ignorance. I did the Sweetwater Mojotone TMB in March and they said no bias needed.

[JMPGuitars]

They're right and wrong. These 18 watt amps are usually cathode biased, and don't generally need to be re-biased once the amp is done. That's assuming good quality, matched tubes.

In reality you still need to check your amp voltages. In this case the power tubes, and see if they're within spec. It's good to test all your voltages though, not just the power tubes.