Valve Factory 18 Amp Kit
Your tone. Your way. Build it. Shape it. Play it.
For decades guitarists have chased the "perfect amp"—that magical combination of warmth, grit, bloom, and feel. The problem? Most amps lock you into one sound. If you don’t like it, you’re shopping for another amp.
The Valve Factory 18 changes everything.
This all-new, StewMac-designed 18-watt tube amp puts YOU in control of your tone. With an open, exposed-tube layout, you can swap preamp tubes in seconds and completely transform the personality of the amp—from silky jazz cleans to gritty '70s rock growl and everything in between. No other amp reacts like this, and nothing this flexible exists at this price.
And the best part? You get to build it yourself.
Build an amp you'll treasure for life.
Like all StewMac amp kits, the VF18 is designed to demystify the world of tube amplifiers. Whether you've soldered for years or have never touched a circuit in your life, our Lego-like step-by-step instructions walk you through the entire build safely and confidently.
You won't just end up with an incredible amp—you'll walk away understanding how it works.
There's nothing like the pride of playing through gear you built with your own hands.
Vintage soul. Modern flexibility. Studio magic.
Inspired by classic circuits from the golden age of American tube amps, the VF18 delivers rich harmonic complexity, natural compression, and expressive dynamics—the tones that shaped legends like Beck, Hendrix, Page, SRV, and Townshend.
It's built for recording, but it has enough punch to make it gig-worthy too. The tone and power are absolutely there, but because the tubes sit exposed on top, the VF18 is best suited for controlled environments like studios, rehearsal spaces, and home setups.
This Amp Features:
- 18-watt, hand-wired tube amplifier
- High and Low input jacks
- 4Ω / 8Ω / 16Ω impedance selector
- Cathode-biased power section
- Two preamp tubes to kick off your tone-chasing adventure: a 12AX7 for classic-rock grit, and a 12AY7 for smooth, jazzy cleans.
- Less than 1 sq. ft. footprint (9" W × 8" D × 6" H)
- Boost footswitch included
Premium components. No shortcuts.
Every component inside the VF18 is high-quality, reliable, and chosen for tone—from the Pacific Trans transformers to the vintage pushback cloth insulated wire, to the matched pair 6V6 power tubes and everything in between. We don’t cut corners on sound, durability, or design. You’re building a real amp, not a toy.
Why players love building the VF18
- It's accessible. Designed for beginners and veterans alike.
- It's educational. Understand how an amp really works.
- It's customizable. No other amp this size lets you shape the tone so dramatically.
- It's inspiring. Few things feel better than plugging into an amp you built yourself.
- It sounds unbelievable. Warm, dynamic, and dripping with tube character.
As one StewMac builder put it:
"The result isn’t just an amp—it's the feeling of accomplishment."
And if you get stuck, we're here to help.
If you get stuck don't worry, we have trained amp tech's on staff who can answer your questions and get you back on track to finishing your amp build. Our amp team is standing by, Contact Us.
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