The Demeter STDB-1A (Stereo Tube Direct Box) is a studio reference vacuum tube DI designed by James Demeter. Created to solve the flat, sterile sound often associated with direct line recording, the STDB-1A places a high-voltage, dual-triode tube circuit directly between high-impedance instrument sources and line-level or microphone-level inputs, adding rich 3D depth, weight, and subtle harmonic warmth.

Featuring two independent channels, each equipped with hand-selected 12AX7 tubes running at full high-voltage plate potential, the STDB-1A offers ultra-high input impedance ($27\text{ M}\Omega$). This extremely high load ensures that passive guitar and bass pickups transfer their full frequency spectrum without loading down the signal path or dulling high-end transients. With both instrument-level and balanced microphone/line outputs, it functions equally well as an active tube direct box or a high-end dual-channel instrument preamplifier.

The Demeter Tube Direct Box is the DI of choice for hundreds of studios, engineers, producers and artists the world over. The clear, warm quality of the Tube Direct enables it to maximize the sound of all types of musical instruments. Whether your application is an acoustic guitar pickup into a porta-studio or thousands of dollars of synths and samplers recorded direct-to-disk, the Demeter Tube Direct Box provides the highest fidelity available.

The Stereo Tube Direct Box (STDB-1) is a two-channel version, packaged in a single rack-mount chassis. It features all the sonic excellence of the Mono Tube Direct Box (VTDB-2B), plus the additional features of variable gain (up to 20dB) in the boost mode and low impedance, line level, 1/4″ output jacks. This is the most versatile of our Tube Directs.

What are some applications of the Tube Direct Box? The Tube Direct Box is being used by top artists, producers and engineers because it enables the true, uncolored sound of electric and amplified acoustic instruments to emerge. Here are some specific applications:

Acoustic guitar: the extremely high impedance (over 20 M) of the Tube Direct insures a perfect match with every pickup to provide a warmer, more natural sound-both live and in the studio.

Electric guitar (clean DI sound): the Tube Direct provides a clear, warm sound that retains all of the guitar’s natural brilliance and harmonics for creating a viable (many feel the only) direct electric guitar sound with or without additional signal processing.

Electric guitar (amplified): the buffered 1/4″ output jack can be used to drive an amplifier through up to 50 feet of guitar cable. It also prevents cable loading to produce a fuller sound from both single coil and humbucking pickups.

Pedalboards and effects devices: the buffered 1/4″ output jack is ideal for running through all types of pedals and effects with virtually no signal loss.

Synthesizers, drum machines and samplers: the Tube Direct warms up the sound of the synthesizer and provides an ideal interface for the variety of synthesizer output levels and impedances.

Digital and hard disk recording: the clarity and sheen of digital and hard disk recording can sometimes seem a little harsh or more brittle than desired. Judicious use of the Tube Direct can often mitigate this problem at several points in the recording chain, including mixdown.