No. You haven't lost any power at all by going to the lower output cartridge. All that you've done is to change the position of the volume control that is required to reach the 30W power capability of your amp, and by a modest amount (about 6db, since the cartridges differ in output level by about a factor of 2).
The main question is whether the background hiss at the higher volume control setting will still be acceptably low. That is a function of the noise performance of the preamp's phono stage, not of the power amp.
Regards,
-- Al
The main question is whether the background hiss at the higher volume control setting will still be acceptably low. That is a function of the noise performance of the preamp's phono stage, not of the power amp.
Regards,
-- Al