I finally put a quad of JJ EL34´s in my AFD to try it out. I´ve only had the chance to test it at home so i need to test it more at my rehearsal where i can play louder.
I set the bias just after the 32 mA mark since it came with the bias at approx 38 mA with 6550´s when i got it. Following the diagram in the manual this should be about the same for EL34´s. Should i turn it up more? It´s a bit hard to see exactly what the screw to adjust the bias is at.
From what i can tell now there seems to be less bass but a bit more attack and bite.
Question the spring retainers that you put over the valve seems to be too big and wide for the EL34´s. But still you can put them over the top of the valve. Will this cause any problem? Are these bigger, wider on the AFD100 since it was built for 6550´s? Then it must be hard to fit 6550`s on an EL34 Marshall.
-- Tue Jun 21, 2011 11:27 pm --
I played the amp with EL34´s at a rehearsal last night and it really sounds thinner, got less bottom end. maybe there is less bass also. I´m not sure i like it with EL34 valves.