Really don't do that. You are totally changing the effective output impedance of the amp and may destroy the output transformer. Then it really would be bad!Lightningeckel wrote:I bought this TH30 after reviewing all the info on the internet, no where did I find any sound clips from the different power settings 30w 15w 7.5w. After a few days of checking it out I noticed the tubes all stay on even when its set to 2 tubes, someone said it was because the power is run off the transformer, so I pulled all the power tubes except 1 and it still ran.!! amazing" but to be honest I cant tell the difference between the 30w and the 15w or 7.5w..they all sound the same. so do I have a bad Transformer? anyone else notice this?
The fact that all the valves still light up in 2 valve mode only means the low voltage heaters are still getting their supply. That doesn't mean that the valves are still getting their high voltage working supplies though - you can't normally see that!
Halving the power doesn't half the volume. To half the volume you need to drop the power to 1/10th!
As already said the differences between the 3 modes will be most obvious at higher volumes, but still won't be that dramatic. Even 7.5W is pretty loud.