Stretched waveform

[lowell]

I'm scoping my custom amp's OD stage and the grid of the second tube stage looks odd. The top half of the waveform is in grid conduction, so it's clipped. The thing I'm not grasping is why it's twice as "long" where it's clipped as the negative part of the signal (which is not clipped). I get that if it's clipped, that part of the signal will "look" longer, but it's not that. At .6vac positive half is 2 times longer than .6vac on the negative side. Anyone have an explanation for this?

[loudthud]

I'm a little unclear on your description of the waveform. How are you driving the grid where the clipping occurs? It's normal for a simple RC coupled grid to skew negative (like a DC offset) because grid conduction. This will affect waveform symmetry.

[balijukka]

If the signal is OK, before the blocking cap, that would indicate that your grid biased positive when idle.
Check that your blocking cap does not leak any voltage to the grid.

jukka

[raiken]

The invert button on the scope channel turned on?

(Don't laugh too hard, I've had to troubleshoot wrong test equipment settings a few times!)

[Enzo]

Amen.