Here my 2 cents about 007 (some redundancy of content with earlier posts).
When I heard first time a 007A (Mk2) in a shop in combination with SRM007tA, it sounded weird. Not that weirdness level like ATH-W5000, but certainly something went wrong in the tuning. I remember worst macro dynamics, muddy bass and the mids indeed completely wonky. This was in 2014 and I was sure I would never get in touch again with this 007 thing. Beginning of 2016 I read Stax “fixed” the 007, so not much later I gave it another chance. Same 007tA in the shop and indeed, obviously 007 was fixed and despite the limitations of 007tA, I liked it – and bought it. So the change in tuning was probably somewhere in 2015. I applied the port mod soon, which made the bass a bit tighter and smaller and brought back the Stax fart. But there was an issue with the treble, a strong peak in the region of I would say 6-7 kHz, which dominated the treble. Reading in the forums and found out I was not the only one noticing this. Corrective action in form of the “spring mod” was easiest possible. Just bend the spring which holds the pads a bit (forgot which direction). Now the peak was completely gone (at least I notice it not anymore) and I thought the missing treble energy was nicely spread into a wide frequency range. Tuned this way I say this 007A is a great headphone that gets my headtime, similar as 009 and X9000. Treble is balanced with very good resolution, dynamics and a little bit of sparkle. Bass is full and punchy with good extension, and this makes a difference compared to 009 and X9000. Precision of bass and overall agility is improving with amplification in a more significant way compared to former headphones, but it never reaches 009/X9000 level. Midrange in comparison is recessed and in case of my 007A I think not just evenly recessed, but this unevenness I perceive is not too much pronounced (for my taste). I think on the one hand the recessed midrange, the overall density of the sound in combination with this unique bass presentation and never stressing treble is appealing for many. But especially the midrange can also be a deal breaker for others. For me on certain days this is exactly the headphone to go, and when switching after a period of listening time to 009 or X9000, I´m almost shocked by how bright and anemically I perceive them. The next day I grab 007 again and no, they might not work for me and I clearly prefer one of the others.
I think a well driven 007 can also work as a “firewall”, at least I´m not tempted to look somewhere in the corner of the planars as for me 007 has enough of what they do best.
Not too long ago I could compare a 007 Mk1 70XXX with my 007A (driven by Megatron and Carbon). I agree with those attesting Mk1 the more even and homogeneous midrange, and I can understand if some because of this prefer Mk1. But IMO this evenness comes at a price. I think Mk1 is overall less macro dynamic and alive sounding. Bass has less punch and although the treble is well extended and I would say even, but it is also kind of subdued, not to say sleepy. Both share the same overall sound signature though. I did not feel the need to hunt a Mk1, but others maybe would. 007A might have the advantage that it sounds appealing “already” on something like a SRM007tA CCS 6S4A, I think a dedicated power plant with a tuning on the “fresher” side is not that much needed to wake it up like I would say this for Mk1.
I hope Stax´ next release would be something like a X7000
