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RE: Here is the schematic for one channel .....

"What are you expecting to have happen?"

A loss of amplifier bass response and a loss of damping factor.

When the cathode is not bypassed to the lowest frequency of interest it allows current feedback to happen at the low frequencies (amplifier bass response loss).

That current feedback will increase the plate resistance of the output tube and that will lower the damping factor (and, depending on the speaker being used, cause the speaker's bass output to increase).

The two in combination can cause bloated, slow sounding bass on most true full range speakers.

On the other hand, some speakers need just that kind of thing to produce low bass.

On the third hand, if the speakers have no output at the lowest of frequencies then the effect might not be heard at all.

I was just saying that technically cathodes should be bypassed all the way down to the lowest frequency that the amplifier is meant to be used at.

For instance, (speaking of just the filter created by the total cathode impedance and the cap) if the -3db point was calculated at 4Hz with a 470uf cap in place (leaving 40Hz completely un-attenuated and phase shift free) then a 47uf cap would give a -3db point of 40Hz (meaning that the amplitude would be down at least some all the way up to 400Hz and the phase would be shifted all the way up to 400Hz)

If it sounded "good" to you, I can't/won't argue with that. But it's just not technically correct.


Have Fun and Enjoy the Music
"Still Working the Problem"

Edits: 06/04/17 06/04/17

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