[glorkaglickflic]

I want to get the 4S because I believe it will give the most accurate response.  I'm looking for as much of a neutral sound as I can get.  I've heard this IEM is quite inefficient.  Would the Asgard 2 be able to drive this IEM to its full potential of should I get a Valhalla or Lyr?  I really like neutral sound.

 

[glorkaglickflic]

Is there anyone who can answer this question?

 

[tomb]

The last I read on Ety's site is that they're providing the ER-4P to ER-4S adapter in the ER-4PT model.  So buy that, and you get everything.  You will probably have to buy it from Ety to get that, though, because all the other stores are still selling old stock of the ER-4PT.  Still, there are adapters that are pretty cheap on ebay.
 
As far as amps, I would stick with something solid-state in the low price range.  Tubes are great, but you really need something on the high end of cost to fully utilize the dynamics and transient detail that the Ety is capable of providing.  Almost any - clean - solid-state amp will provide enough power for an ER-4S.