I am potentially interested in purchasing a JH audio custom IEM. I figure they fit my sound signature requirements the best since I'm looking for an improved UE TF10 (maybe less recessed midrange) with better fit. However, I won't be using them with an amp most of the time (let's say about 50-60% of the time), so I'm wondering which is the best JH model to go with if I'm not going to be using the very best DAC and very best amp.
Obviously I expect a JH16 to sound better than a JH5 even without an external amp, but what do you guys think is the point of diminishing returns for my case? Don't want to spend hundreds more if there's going to be marginal differences without an amp.