Copland CTA 405 bias adjustment

[Gatto55]

Need help figuring out bias adjustment procedures for vacuum tube amplifier.
A technician told me to check the bias adjustment every 6 months….. problem is I have absolutely no idea how to do it. Furthermore, they charge an arm and a leg every time I bring the amp in.
Any help would be kindly appropriated.

 

[grovergardner]

Is this your amp? Bias instructions are further down the page.

https://copland.dk/cta405a

 

[Gatto55]

Thank you.