6sn7 cathode follower tv#

In any case, I would not start any kind of low level, and hopefully linear, preamp stage with a pentode, due to its distortion issues (yes, there, I said it) particularly the predominance of odd harmonic distortion. Often these circuits where constructed with cascode circuits, too, to take advantage of the low capacitances and (one advantage I forgot to mention) the lower noise offered by the cascode stage over a pentode. This is one of the first 'frame grid' tubes which allowed the reduction of the cathode to grid space.

6sn7 cathode follower tv#

The 6DJ8 was designed as an high frequency amplifier and mixer for the tuner and RF amps of TV sets. A 'real' triode would be better in that position. I don't know if an EF86 operating in triode mode would be the best way to kick off the cascode. any truth in that one?Īnd hey, maybe i'll just see if i can make a single rc triode work before i try tackling complex sh*t also, based on some of my reading last night, i got the impression that the ef86 isn't the greatest tube of all. and i guess i'm still wondering, and wish i had the experience and insight to understand what about a cascode might beg of its valves matched specs.Īnyhow. i find bullshit on my own without much trouble at all.Īnyway, the original question was asking if an ef86 as triode could be cascoded with the triode in 1/2 of a 6sn7. I do in fact ask questions here because there are good people that refuse to type bullshit. I read a bunch of stuff, and i was reading the section on cascodes, cathode followers, white cathode followers, etc, in 'valve amplifiers' last night, the author states that most dual triodes wont work well as a cascode, and that the 6DJ8 was the only tube designed to be a cascode. I am thinking two channel, 300v b+, and have 4 6sn7's available, so perhaps i could do it all with 6sn7's. i could find use for them else where i'm sure. Well, perhaps i can drop my idea of using the ef86. Moderators can go ahead and scold me for the 'attack' but i believe its everyones responsibility to call out bullshit- since this is after all supposed to be a technical forum. i wouldnt bring this up except you prance around here acting like you know everything- and some poor souls who dont know better might even believe it. if you dont know the answers to his questions, youre under no obligation to reply anyway!įor someone who claims to have a masters degree in electronics, you sure dont display much knowledge beyond what a hobbyist or anyone who reads 'audiophile' web sites would know. Ok, well the guy already knows what a cascode is, and he didnt ask for your opinion on their sound or 'distortions'. It is good for very high frequencies, however I don't use them on AF because I don't like their distortions. The upper tube (actually it may be a transistor) works with a 'common grid' (or common base in case of transistor). Cascode minimizes Miller capacitances loading the tube on very low dynamic resistance.