Speaking as a musician who has helped many people train their ears, ear training is like any other kind of training. It takes regular practice. The more you work at it, the better you will become. Almost anyone can improve their listening ability, no matter whether it is learning to detect slight differences between two different tubes, or systems, or whatever, or the more complicated listening musicians themselves have to do.
Rather than make ear training specific to trying to hear differences between pieces of equipment though, I always like to encourage audiophiles to train their musical ears in general. Working on this greatly improves all types of listening. Learning more about music in general will also greatly increase your enjoyment in listening to whatever kind of music you like to listen to. It is easier to pick out what type of equipment you want when you know much more about what it is you are trying to listen for. Many audiophiles know a very great deal about the science of music playback, but shockingly little about music itself and how it is put together. It is especially shocking and saddening to me when I encounter someone who has spent six figures on their system yet knows almost nothing about what they are actually using the system for.
I always recommend a great little book the famous composer Aaron Copland wrote, entitled What To Listen For In Music. It is an excellent book written in layman's terms, and will increase your enjoyment in listening to whatever kind of music you like to listen to (it is not just for classical music, though it does focus on that, since it is generally much more complex - if you only listen to say rock, then what the book will teach you will be that much easier to apply).
Rather than make ear training specific to trying to hear differences between pieces of equipment though, I always like to encourage audiophiles to train their musical ears in general. Working on this greatly improves all types of listening. Learning more about music in general will also greatly increase your enjoyment in listening to whatever kind of music you like to listen to. It is easier to pick out what type of equipment you want when you know much more about what it is you are trying to listen for. Many audiophiles know a very great deal about the science of music playback, but shockingly little about music itself and how it is put together. It is especially shocking and saddening to me when I encounter someone who has spent six figures on their system yet knows almost nothing about what they are actually using the system for.
I always recommend a great little book the famous composer Aaron Copland wrote, entitled What To Listen For In Music. It is an excellent book written in layman's terms, and will increase your enjoyment in listening to whatever kind of music you like to listen to (it is not just for classical music, though it does focus on that, since it is generally much more complex - if you only listen to say rock, then what the book will teach you will be that much easier to apply).