Traynor YBA200 Tweaks & Observations

[Stuart O)))]

Had another failure in my YBA200 which is now a YBA200-2. One of the pentodes failed v4. It arced internally and blew R66 which is a 2ohm 2W metal film resistor. I beleive that it is the plate biasing resistor(?). Anyhow if you want to read more about my home repair and see PICTURES OF THE INSIDE of the amp check this link:

Something broke in my bass amplifier | Facebook

 

[Aussie Mark]

Necro bump for this thread. How many of you with an original unmolested auto biasing YBA200 have made the switch from 6550 to KT88 power tubes? Any issues?