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Re: pentode in triode mode SE vs a DHT SE like 2a3/300b

The reason, possibly the ONLY reason, why those antiquated DHTs from eighty + years ago are still popular and still produced, is because they are amazingly linear. Just have a look at the plate curves for a 300B or 2A3 and compare them with those of a triode-strapped pentode or beam tetrode, and you'll see what I mean - the difference is quite dramatic.

The consequence of this is that a triode-strapped pentode/tetrode produces more odd-order harmonic distortion. A DHT has plenty of second-order and a much lower amount of third-order, and that's about it. A triode-strapped pentode/tetrode produces also 5th and 7th order distortion, which can make it sound harsher. I don't believe the bass sound is any better or worse, but at the middle and treble frequencies the difference would be audible with a decent speaker and SET fans tend to be particular about this sort of thing!


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