01-11-2016, 07:29 PM
(This post was last modified: 01-11-2016, 07:30 PM by Murphyv310.)
Hi Mark.
What we want here is a decent drive for the EL84. On the face of it 25V P-P will be fine but with the values used to get that amount of drive there will be loads of distortion. With the "correct" values you could be getting 100V P-P or more with the same distortion but your EL84 will be driven hard so reducing the input or volume will reduce the distortion and you'll still have enough drive to get 3-3.5 watts of undistorted output.
Personally I don't like low value volume controls for the reason that it can cause bass roll off due to the time constants of the input "R" of the VC vs coupling cap or the coupling in the source.
I'm very much a firm believer that traditional values work better than some of the so called "new" designs in valve circuitry.
What we want here is a decent drive for the EL84. On the face of it 25V P-P will be fine but with the values used to get that amount of drive there will be loads of distortion. With the "correct" values you could be getting 100V P-P or more with the same distortion but your EL84 will be driven hard so reducing the input or volume will reduce the distortion and you'll still have enough drive to get 3-3.5 watts of undistorted output.
Personally I don't like low value volume controls for the reason that it can cause bass roll off due to the time constants of the input "R" of the VC vs coupling cap or the coupling in the source.
I'm very much a firm believer that traditional values work better than some of the so called "new" designs in valve circuitry.
