Dual 6J5G for output tube

[jt]

I normally use TS5998 as my output tube but have been using dual 6J5G (GEC CV1067) as output.
Sounds great!
Better than TS5998.
Has anyone else tried this?
Is it even advisable?

My input tube is TS VT-99.

[Paul Birkeland]

This is an incredibly bad idea, please do not do this! 

You will run the 6J5s at 150% of their rated maximum cathode current, that is bad.
The output impedance of the amp will increase to over 300 ohms, that is bad.
The 6J5 grid bias voltage will be positive with respect to cathode, so you'll be drawing grid current.  This will damage the 6J5s and load down the 12AU7 driver tube.  This is really bad.
If the grid doesn't overheat and fail first, you'll be running up against the plate dissipation limits of the 6J5s as well.

I'm sure your amp sounds a lot different, but different isn't necessarily always better.

[larcenasb]

Eeek, yeah, ask if it's advisable first! Stay safe.