I just used the Naztech external all weekend at LOCKn that Tonedeaf hipped me to and it worked like a champ. No issues and it comes with a tip that fit perfectly. Ran it a 9V.
Mics: Schoeps MK5, Schoeps MK41, AT853u (C,SC,H)
Preamps/converter: Schoeps VMS52UB (x2), Nbox (x2), Grace Lunatec V2, Sound Devices MP-2, DPA MMA6000, Naiant Tinybox v1.5, Benchmark AD2k+
Recorders: Tascam DR-680, Korg MR-1, Edirol R-05, Sony M10