Is biasing necessary?
Aha, the issue of issues. It’s wise to have it done when you change power valves, yes, though not always an urgent necessity – depends on the situation. Usually I bias for power and clarity. But it’s your choice. If you want me to go for less volume and a browner, distorted sound, let me know – some amps suit this approach better than others. Timescale? It’s not going to take me long to adjust your bias in most cases. See blog for more on this controversial issue.