I’ve been a fan of Roswell Pro Audio’s mics since they sprouted from the mind of Matt McGlynn, and even prior to that, with his MicParts kits and mic mod site (I built and reviewed their original 12-251 kit back in Tape Op #128). The Roswell Aztec is the logical evolution of both the MicParts 12-251 and V-251 models into a fully boutique mic (one that doesn’t need to be assembled by the end user) and ups the game as far as components and performance go. It’s also priced very reasonably for a fully handmade, multi-pattern tube mic that performs as well, if not better, than many microphones that cost considerably more.
The Aztec is loosely based on the Telefunken ELA M 251, but it’s definitely not a clone. The capsule is Roswell’s bespoke RK-251, and the circuit is also of their design. They use a carefully selected and tested 6072 tube in a single-triode configuration. There is a custom-wound European-made output transformer, and the rest of the components are all specifically chosen to ensure the highest possible quality of the recorded signal; they don’t source inexpensive parts to save a buck – they even go so far as to have custom electrolytic capacitors made for the Aztec and its power supply. The power supply is itself a work of art, fully regulated and running at a higher voltage than the standard off-the-shelf tube mic power supplies common with many lesser mics. The rectifier diodes and resistors in the power supply are all audio grade to ensure the best possible consistency of voltage to the tube and capsule.
The Aztec ships with a Gotham Audio cable terminated in Neutrik 7-pin connectors; these are wired in-house at Roswell and burned in for 72 hours. The package also includes an AudioQuest IEC cable, a shock mount, and a padded pouch for the mic, all within a hard case with laser-cut spaces for each component. It all feels very intentional.