We've recently worked with Iron Age Audio to have PCB's made for our Downbeat style Gate' SA-70 preamps. The intention was to also start selling the PCBs populated and unpopulated for DIYers who want to build these great preamps. We now have the unpopulated PCBs available for sale.

The ‘DB-70’ is our version of the Gates SA‑70 preamp. The DB-70 is a classic tube-based microphone preamplifier from the mid-20th century, valued for its rich tonal character, transformer-coupled signal path, and flexible tone-shaping capabilities.

Historical Context & Lineage:

• Originating from vintage broadcast and studio gear, the SA‑70 shares its heritage with designs from Western Electric, Langevin, and RCA—all renowned for premium transformer-based audio circuits
• A two-stage tube circuit incorporating octal-based triodes/pentodes like the 6SJ7 and 6C5 with transformer coupling on both input and output
• Crucially, it employs adjustable negative feedback and bass/treble shaping by routing capacitors within the feedback loop—yielding transparent warmth or aggressive coloration, depending on settings
• In recreations, turning down feedback produces clarity and punch; increasing it yields a smoother, creamier tone

You can access assembly instructions and part list on our website.

This listing is for a single unpopulated PCB. The picture with the PCB populated is just an example.