Removing 2 Power Tubes

[spoonman]

According to the schematic of the OR 120 head,
the ony difference between it and the OR 80 is
the number of power tubes. No other mods need
to be made? Capacitors or resistors? I don't
want to do any damage over the long term.

[bclaire]

Actually, any four tube power section amp can have the outer two tubes removed for half power (Marshalls, Fenders, etc). The impedance needs to change to the cab though- and I forget exactly what you're supposed to do except <i>I think</i> a 16 ohm cab would then need 8 ohm selected on the head.

It sounds like a good idea in theory but db's are exponential- meaning to get one db louder, you have to double the wattage.... which means your mod will result, in theory, in 1 db less volume. In my experience with two Marshall Superleads, I found that there was almost no discernible difference between full power and half power. And my 80 watt Oranges are super loud as they are! Billy