Our Process
How an amplifier is made.
Every Drive-in Amplifier is built one at a time, in Washington State. These are the stages each one goes through, in the order they happen.
The Housing
The drive-in speaker housing, two ways.
The housing is a drive-in theater speaker, the box most people picture when they think of a drive-in. We build in two kinds.
- New castings
- New castings of the RCA case, made to the original pattern. Every one is identical and ready for the finish you choose.
- Vintage originals
- Genuine period speakers recovered from real drive-ins, sourced one at a time. They are not all RCA: each is whatever that theater installed, and every case is listed with what we know about it. Each one is cleaned, stripped and inspected before we build with it. The casting marks and small imperfections are kept.
Either way, the amplifier inside is the same.
Vintage Originals
How we prepare a vintage case
Every recovered case goes through the same six steps before it is powder coated. Cast aluminum that has spent decades outdoors holds oil, oxidation and moisture in places you cannot see, and any of it left behind shows up later as a bubble or a pinhole in the finish.
Heavy degreasing and deep cleaning
We scrub the raw casting thoroughly with a heavy-duty industrial degreaser, using a stiff nylon brush or abrasive pad. This breaks down surface grime, road film and the oil sitting on the metal. Then it is rinsed completely with clean water.
Acid etching and brightening
A dedicated aluminum acid-etching cleaner strips away invisible oxidation and chemically micro-etches the surface, which gives the coating the best possible profile to adhere to. It is washed off thoroughly so no chemical residue remains.
Mechanical scuffing
Every outer surface and crevice is hand-scuffed with a fine non-woven abrasive pad. Because we use no abrasive media blasting, this step is essential: it creates the microscopic scratches the powder physically grips.
Thermal outgassing (pre-bake)
The bare metal is heated in our curing oven at 400°F–425°F for 45 minutes. Cast aluminum is porous, and this forces deeply trapped oils, moisture and manufacturing residues out of the pores so they cannot bubble or pinhole the final finish.
Surface repair and filling
Pitting, deep gouges and cracks are filled with a high-temperature, heat-resistant metal repair compound. Once fully cured, the repair is heat-set and sanded flush until its edges merge seamlessly with the casting.
Final solvent wipe
Once cool, the prepared housing is cleaned with a fast-evaporating, residue-free solvent such as acetone or high-purity isopropyl alcohol, using a lint-free cloth, to remove any remaining dust or skin oils before the powder goes on.
The Finish
Powder-coated in our own shop.
Powder coating is a dry finish, applied electrostatically and cured with heat. It is thicker and tougher than paint, and it gives the deep, even gloss you see on the amps in the collection.
We do this ourselves. We own the oven and we set the schedule, which means we control the color, the gloss, and the cure on every housing. It also means we can usually coat a color that is not in the collection.
Vintage originals go through the same process after cleanup, so they get a new finish over the original casting.
The Circuit
What makes it a true guitar amplifier.
What we mean by a true guitar amplifier:
- Hand-wired on a turret board
- Components are mounted on turrets and soldered by hand on the bench, the way amplifiers were built before circuit boards. It takes longer and is easier to service, and every amplifier is assembled by hand.
- Three controls
- Volume, Bass and Treble, on three knobs along the top edge. Those are the only controls. Everything else is chosen when you order.
- One input
- A quarter-inch jack. On an RCA housing it sits in the recessed scoop on the face, where the original speaker's hardware used to be. On a vintage case from another maker, we agree the layout of the jack and controls with you before we build.
Voiced by Hand
Every amplifier is played before it ships.
Once an amplifier is built, we plug it in and play it on the bench, adjusting it until it sounds right. Then it gets its badge and is packed.
Because each amplifier is built by hand, two in the same color will be close but not identical.