Hi all, long time lurker, but finally decided I need some help with some decisions! I'm looking to buy a tube amp to use with my HD600's. Problem is, I can't decide which to choose. I've narrowed it down to a few options. I'm not looking for a write-up on any of these pieces, as I've already read the write-ups on head-fi. I'm looking at the WooAudio 3, (possibly the 6 if it's really worth it), the Bottlehead Crack (with speedball upgrade), the Little Dot MKIVse and the Schiit Lyr. I've looked at the Ming Da and a few others but I think (from what I've read) that these would be the best match for the HD600's. Problem is, they're all basically in the same price range, and there's no way for me to listen/inspect either of them before buying one. I'm definitely going to be rolling tubes. I'm not sure if that eliminates the Lyr; Skylab reviewed the similar Valhalla, and indicated that if tube rolling was the intention, to overlook the Valhalla. I'm not sure if the Lyr is any different in this regard (although I did see a tube rolling thread for the Lyr). Does anyone have any experience with the HD600 and any of these amps? There are a few threads for "Best amp for HD600" etc, but none of them compare these amps. If anyone could provide absolutely any guidance, it would be immensely appreciated. Thanks!