I'm a happy owner of an Ampeg B-100R and have been looking at the B-200R with keen interest. I like the tube in the preamp and the extra power of the B-200R. I guess my question to you out there with experience with these two amps is, are the sonic differences between these two amps significant enough for me to make the upgrade. In reality, and extra 100 watts is not a lot louder and can you hear the tube in the preamp?