In Reply to: OTl clipping vs Transformer clipping posted by tesla on June 19, 2005 at 21:44:47:
Except for some HF filtering of the upper most harmonics in a clipped wave, there shouldn't be much difference in the sound when both amps are using the same output tubes. The reason tubes can be used nearer the maximum power output compared to transistors, and thus tube watts are more than transistor watts, is because of the compression that occurs as the tubes near saturation. A transistor going into saturation will do so abruptly, and create a sharp edged clipping of the signal. A tube will start to lose gain as it nears saturation and will ease off a little before it saturates, so the clipping is smoother with lower order harmonics, which is easier on the ear.
Different type tubes should behave differently in how abruptly they saturate.
I am not 100% sure, but just trying to reason with how tubes work, I think tube types with low internal plate resistance will probably saturate more abruptly than those with high internal plate resistance since they work farely well with relatively low anode voltages. But µ should have a factor in this as well, (of course - they are related), and a high µ tube should also saturate more abrupt than low µ types. Since low µ means low plate resistance when transconductance is equal what I have just said kinda doesn't make sense. Perhaps there is a crossing point in sharp and smooth saturation where µ and rp is in a certain relation to each other. Anyone else have any more experience with what makes a tube saturate sharply or smoothly?
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Follow Ups
- Re: OTl clipping vs Transformer clipping - Nick 04:37:57 06/20/05 (1)
- Re: OTL clipping vs Transformer clipping - Ralph 09:25:56 06/20/05 (0)