I tuberoll both in my headphone amp and I have to say Tesla wins hands down. The Mullard is very very smooth but it doesn't have the HF extension and dynamics of the Tesla and its 2x the price. Mullard EL-34s are now just sitting in my store room.
My hypothesis on why the Mullard costs more boils down to reputation in the old days. When a generation got used to its smooth laid back signature, its hard to switch to anything else. However, they were listening to pretty bad sources in the old days.
My hypothesis on why the Mullard costs more boils down to reputation in the old days. When a generation got used to its smooth laid back signature, its hard to switch to anything else. However, they were listening to pretty bad sources in the old days.