Tube preamp topologies and music

Push-pull can have superior signal-to-noise (SNR) ratio and less harmonic distortion due to the self-canceling effect of a balanced circuit. Also there is no DC current flowing in the output transformer of a push-pull circuit. 

AudioXpress magazine had a good article on building a single-end 211 amp some years ago. The authors cautioned that such a project was not for the inexperienced! I suggest you track down this article! I no longer have my copy. Another valuable source of information on tube amp design are the issues of Sound Practices - recommended! Lastly, find issues of Glass Audio - more information on design and construction of tube amps.

Great thanks

A push-pull 211 can have double the power in watts of a PP KT88/6550 amp. With correspondingly more expensive parts/output transformer. Doubling the watts only gives a 3db increase in volume level. Not much!

A OP - As to your specific question, single ended 300B amps tend not to be very well controlled in the bass - even with efficient speakers.

A 300B valve is only good for a couple of watts before it starts to distort. A say eight to ten watt advertised SE 300B amp will not deliver that wattage at 1%THD.

So they are not a good choice for rock music.

The following link will give you a good overview of technical issues related to SE amps - a "high powered" one in this case.