with the led at the moment I enjoy a lot, but I am going to increase the grid stoppers of the 6j51p/ef184 and 211, yesterday listen a philharmonic orchestra with all violin at time, listen same noise with the rest of the instrument are perfect. The 6j51p has 300R as grid stopper, need to increase to 1k or 2k, the 211 don't have grid stopper maybe with 1k, all oscillation will be controlled.
I like a little bit with the CCS over the resistor load, but is clear that the CCS eat same db in the bass, I am waiting the zener 15v to protect the dn2540, I have broken 8 pcs in 5 month 😕 my B+ go to 420v at the start.
I like a little bit with the CCS over the resistor load, but is clear that the CCS eat same db in the bass, I am waiting the zener 15v to protect the dn2540, I have broken 8 pcs in 5 month 😕 my B+ go to 420v at the start.
I once used a 1 uF capacitor of good quality parallel to the led under the tube. That gave a huge improvement of the sound quality. Just try it
fet as cathode follower, needs it?
This week I have put 2.6V battery cathode bias, I like more than traditional resistor and led.
The load of the EF184 follow by 20k resistor, I listen clearly that the sound is good but better with CCS ( dn2540 cascade). I have change the coupled capacitor the K40 PIO have been replaced by Silver mica Russian NOS, I like more the silver mica, has a lot of more details and the bass run faster than before, now is more dynamic and the silence are beautiful ( recommended )
My question is :
The EF184/6j51pp work on (190v-230v) and 10mA, the swing is a ok but a little just to the 211 to have a good headroom.
would be better to the 211 drive by fet cathode follower, as 2sk2700 ?
The cathode follower give same gain more?
This week I have put 2.6V battery cathode bias, I like more than traditional resistor and led.
The load of the EF184 follow by 20k resistor, I listen clearly that the sound is good but better with CCS ( dn2540 cascade). I have change the coupled capacitor the K40 PIO have been replaced by Silver mica Russian NOS, I like more the silver mica, has a lot of more details and the bass run faster than before, now is more dynamic and the silence are beautiful ( recommended )
My question is :
The EF184/6j51pp work on (190v-230v) and 10mA, the swing is a ok but a little just to the 211 to have a good headroom.
would be better to the 211 drive by fet cathode follower, as 2sk2700 ?
The cathode follower give same gain more?
The swing of the CCS 6j51p is not bad for 211, Mu 80 192Vpp but I am not sure about the current
How many current mA need the 211, is difficult to know, but is true that all 211 with excellent sound have a big drivers with more current. This is why I think that a SS cathode follower maybe is the way
Of course that the 4P1L is a good drive for all Big DHT, at the first I use the 6e5p as the 4P1L both are good but without enough gain to drive in two stages the 211
How many current mA need the 211, is difficult to know, but is true that all 211 with excellent sound have a big drivers with more current. This is why I think that a SS cathode follower maybe is the way
Of course that the 4P1L is a good drive for all Big DHT, at the first I use the 6e5p as the 4P1L both are good but without enough gain to drive in two stages the 211
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