United Studio Technologies Vintage Direct & Replay Box

The Replay Box: a re‑amp device with tonal options to explore.

These high‑quality boxes promise to add more to your rig than most DIs and re‑ampers.

Based in Baton Rouge, Louisiana, United Studio Technologies were founded with the aim of opening up access to “gear built like the original classics”. Having opened their account with reworkings of two popular vintage microphones, they’ve now released another product pairing: the passive, transformer‑based Vintage Direct Box and Replay Box re‑amping interface.

Appearance

Each of these devices sits in an identical, brushed‑aluminium enclosure, whose recessed front and rear panels carry matching control and connector layouts. Internally, the Vintage Direct carries one transformer, whilst the Replay has two. These and all other components in both units are of extremely high quality, right down to the three resistors in the Vintage Direct’s switched attenuator that are made by a supplier to NASA.

The Vintage Direct.

The front panel of the Vintage Direct carries a centrally positioned row of three miniature switches. These activate, from left to right: 12dB of output attenuation; an output polarity reversal; and a ground lift. To their right, a three‑position rotary switch selects between the three secondary windings of the unit’s transformer to deliver, in conjunction with the 12dB output attenuator, six output level options from ‑42 to ‑22 dB in 4dB steps. The Vintage Direct’s rear panel carries a balanced male XLR for the DI output, and two quarter‑inch (6.35mm) jack sockets, one for the instrument input and the other for a pass‑through of the input, for onward connection to an amp, effects processor or pedalboard.

The rear panels of the two boxes share broadly the same layout, though obviously the I/O support different functions.The Replay Box’s leftmost front‑panel switch toggles between the unit’s two transformers, to offer either Transparent or Harmonic colour options. The rest of the switches on the front panel have the same functions as those of the Vintage Direct. The output level control’s rotary potentiometer, in this case labelled Level rather than Output, has a practical range of ‑75 to +4 dB, beginning at full attenuation. At the unit’s rear, you’ll find a balanced female XLR input connector that accepts +4dBu line‑level signals; a quarter‑inch jack socket that can act either as a pass‑through of the signal entering the XLR input or (if the XLR is not in use) an input; and a quarter‑inch jack socket that carries the Replay Box’s output signal from the selected transformer.

Transformers

The transformers in both the Vintage Direct and the Replay Box are the fruit of a collaboration between United Studio Technologies (UST from here on) and studio engineer Chad Kelly, whose 20 years of experience in the design, development and production of boutique, hand‑built passive transformer‑based DI and re‑amplification boxes lies at the heart of these new units.

In the Vintage Direct brochure, the direct inspiration of the transformer in the Vintage Direct is given as the...