The real use for a tube buffer is not to tailor the sound, though it will for better or worse, but to make impedance differences between source and preamp or preamp and amp more system-friendly. This is accomplished via a high input impedance on the buffer, which in turn outputs a very low impedance.
The EE BBA I used for impedance matching added other things to the sound I didn't like.
The EE BBA I used for impedance matching added other things to the sound I didn't like.