Yeah, the Crack is meant for 200ohm and higher headphones. The S.E.X. should work with just about any ohm headphone. It is fairly small at 8"x10" which is really good for a headphone and speaker amp. Plus you can upgrade what ever parts you want. The 6FJ7 tube is also really cheap to get replacements pairs and for tube rolling, not sure if there is a lot of difference between the tubes brand. I've never tried the S.E.X. amp before but it seems like a very versatile amp. I skipped over the S.E.X. from the crack to the mainline and the Kaiju. I also got that email about it being discontinued. I think the owner of Bottlehead is retiring.