WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
Here again the two tubes sound different. Your choice depends on your ears listen to both and chose what you like. It is possible to build an amp that will work with both tubes. I have done this and I have listened to both tubes ( new Chinese, and old RCA) and I prefer the 845. You may prefer the 211. I can't tell you what you like. I like loud rock music. Do you?