These are a marriage of various drivers with new Beyer DT770 Pro shells, along with my other mods for them. As with any marriage, it winds up costing more than staying single, but can be a rewarding experience!… I will also consider using any other drivers that you provide (more on that below). Denon and Grado are the most popular choice for drivers.
When using Grado drivers, to me they sound somewhat similar to V10 C-Pads, but better… The drivers are tweaked and closer to ears in these, plus the driver housing being glued to the V4 Korina soundboard rather than pressed in. I'm now using one-piece Korina soundboards to mount them on. For V4, I use a damping technique to give less bass prominence to Grado drivers for a quite even sound.
Their design is open back (semi-closed for Grado), with domed stealth stainless steel screens. Beyer shells are both comfy and sturdy and look sweet IMO.
Drivers can either be purchased from me, or you supply them. They must be attached to the stock headphones when I receive them (I won't accept just drivers). I keep all spare parts from both headphones. COA's will have drivers listed on them, thus verifiable for all in future.
Minimum SR325i for Grado builds. New SR325i drivers are available from me for Vixens (may or may not add time to build due to availability). You could also have me use your RS-1 or 2, GS/PS1000 or Joe Grado pair (have built multiple HP1000)... or whatever you have that I approve of using.