New Tung Sol 7581a power tubes

[Downunderwonder]

Thanks, not much the wiser, could we carry on with that here please..My Mesa d180... | Page 12 | TalkBass.com

Their approach for the master is not what you normally have in other amps which is a pot that acts as a voltage divider, reducing the signal level that gets to the power amp. In the case of the D-180, from what I see on a hand drawn schematic that I found, they use a tube stage to control the signal being passed on to the power tube stage. They do this by adjusting the cathode resistor of this stage, thereby adjusting the current through the tube. A different way of controlling the signal being passed to the power stage.