On most tube amplifiers its a good idea to try the Sound Lab on the various taps of the output transformer to see which works best.
Some transformers can ring if not properly loaded- so if you are on the 8 ohm tap and the amp is playing into a 30 ohm load on a bass note, you may get increased distortion (lower ordered harmonics) that might cause the amp to sound warmer than is actually correct. It depends on the design of the amp as to whether there will be a significant loss of power with such a mismatch, but IME usually the loss of power is slight. If the amp has negative feedback most of the distortion will be controlled but that can be a double edged sword as with more feedback comes a greater tendency to behave as a voltage source.
With our MA-2 (about 70% of our production in the last 20 years are driving Sound Labs) there is also a slight loss of power into 30 ohms (about 10 watts), but distortion is actually reduced into the higher impedances.
In short, this is a speaker that benefits more than many box designs from a slightly higher output impedance in the amplifier.
Some transformers can ring if not properly loaded- so if you are on the 8 ohm tap and the amp is playing into a 30 ohm load on a bass note, you may get increased distortion (lower ordered harmonics) that might cause the amp to sound warmer than is actually correct. It depends on the design of the amp as to whether there will be a significant loss of power with such a mismatch, but IME usually the loss of power is slight. If the amp has negative feedback most of the distortion will be controlled but that can be a double edged sword as with more feedback comes a greater tendency to behave as a voltage source.
With our MA-2 (about 70% of our production in the last 20 years are driving Sound Labs) there is also a slight loss of power into 30 ohms (about 10 watts), but distortion is actually reduced into the higher impedances.
In short, this is a speaker that benefits more than many box designs from a slightly higher output impedance in the amplifier.