Gates 3638 SA-134 Tube Microphone Preamp

If you're chasing the sound of 1950s–1960s American broadcast and recording studios, the Gates SA-134 delivers it. Thick low end, forward mids, and beautiful tube saturation when pushed.This unit has been professionally built in the spirit of classic broadcast equipment, using high-quality vintage transformers and NOS RCA tubes.The SA-134 shares much of its design DNA with our Downbeat DB-70 builds, but adds an additional tube stage and a different output tube configuration, allowing for greater harmonic complexity, headroom, and tonal control.Tubes:6S76SJ76SN7The external power supply uses a NOS Tung-Sol 6X5GT tube rectifier, providing smooth power delivery while helping keep the preamp quiet and stable.This unit uses high-quality vintage broadcast transformers:Freed input transformerCollins output transformerThese pieces of iron are a major part of the classic broadcast sound — delivering weight, depth, and musical saturation.Front Panel Controls:Input Pad: -40 / -30 / -20 / 0 dBVariable Gain ControlVariable Negative Feedback (controls harmonic density and character)Switchable Low Frequency ResponseVU Meter Defeat Switch (protects the meter when driving the preamp hard)Front Panel DI InputExternal Power Supply:The preamp is powered by a tube-rectified external power supply, which helps reduce noise and keeps heat away from the audio circuitry.Included with the unit:Power supply cableIEC power cableStudio Applications:This preamp excels anywhere you want weight, dimension, and vintage tone.It can run clean and open, or be pushed into rich tube saturation reminiscent of early rock, jazz, and broadcast recordings.Built by Downbeat Studio & DesignEach unit is built with the goal of capturing the character and sound of classic recording equipment while making it reliable for modern studio use.