It is the opposite of remote cut-off.
Remote cut-off means that gain "tapers off" towards the extreme of grid voltage instead of rapidly declining at some point, which in turn means the gain is not linear throughout the Vg range. This is useful for certain purposes (amplification of RF signals, especially in FM/limitting and AGC) but straight audio amplification isn't one of them (they could be useful in audio compressor circuits though).
Sharp cut-off means that gain is more linear with grid voltage and that tube will cut off (= current through it will decrease dramatically) at and below certain grid voltage. This is useful for audio since you get maximum linearity, as long as you don't drive the tube into cut-off, of course
Remote cut-off means that gain "tapers off" towards the extreme of grid voltage instead of rapidly declining at some point, which in turn means the gain is not linear throughout the Vg range. This is useful for certain purposes (amplification of RF signals, especially in FM/limitting and AGC) but straight audio amplification isn't one of them (they could be useful in audio compressor circuits though).
Sharp cut-off means that gain is more linear with grid voltage and that tube will cut off (= current through it will decrease dramatically) at and below certain grid voltage. This is useful for audio since you get maximum linearity, as long as you don't drive the tube into cut-off, of course
It is the opposite of remote cut-off.
Remote cut-off means that gain "tapers off" towards the extreme of grid voltage instead of rapidly declining at some point, which in turn means the gain is not linear throughout the Vg range. This is useful for certain purposes (amplification of RF signals, especially in FM/limitting and AGC) but straight audio amplification isn't one of them (they could be useful in audio compressor circuits though).
Sharp cut-off means that gain is more linear with grid voltage and that tube will cut off (= current through it will decrease dramatically) at and below certain grid voltage. This is useful for audio since you get maximum linearity, as long as you don't drive the tube into cut-off, of course
THANKS
I will make some experiments and see how the sound is,maybe i will test it as phase splitter?
You might try the Pentode section at Ik=17.5mA, Vk=200V (supply around 300V), Vg=-2.5V with a 56K plate load as a gain stage. Pentodes tend to be a bit noisy due to partition noise, but it looks pretty linear there, although that is pretty hot for plate dissipation (3.5W) but below design max (3.75W).
Gimpy,
It seems the triode is quite close to that found in the 12AT7. What's your opinion of using the 6AW8 in a Dyna/Scott style power amp front end? FWIW, I think that LR8 regulating g2 B+ (for linearity's sake), at 150 V., rates to be correct.
Not specifically an audio type,but 6AW8's were widely used by AMPEX in the preamp circuits of their vintage professional tape recorders (602 , 354 , PR-10 , ...) , which are still appreciated today for their great sonic performances. A cheap and versatile tube with good audio potential: maybe a "sleeper" ?
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