Tech 21 NYC Custom Lab

Private Stock

Exclusive Handcrafted Innovations, Custom Tube Circuits & Masterpiece Engineering by Tech 21 Founder Andrew Barta

Master Artisan Audio Lab

Boutique Analog Engineering & Custom Creation

Tech 21 was founded when Andrew Barta revolutionized tone shaping with the original SansAmp. The Private Stock division opens the doors to Andrew’s personal engineering workshop — offering limited-run, custom-built preamplifiers and boutique tone tools crafted for discerning tone purists and global audio professionals.

Pure Analog Path

100% discrete analog circuitry ensuring zero latency, pristine signal fidelity, and dynamic response.

Handmade in USA

Custom built, hand-soldered, rigorously tested, and voice-calibrated at our New York factory facility.

Founder Designed

Directly conceived and engineered by Andrew Barta without mass-production compromises.

Global Procurement

Full support for international distributors, pro audio buyers, touring rigs, and boutique collectors.

Limited Edition Series

Boutique Hardware Showcase

Each Private Stock unit is produced in limited quantities using premium-grade components, solid hardwoods, and custom audio-grade transformers.

Flagship Custom Tube Preamp

Formula 21 Vacuum Tube Bass Pre-Amp

Conceived by Andrew Barta to explore the iconic SansAmp Bass Driver architecture executed entirely through high-voltage vacuum tube technology. The result is a warm, harmonic-rich tube preamplifier offering incredible touch sensitivity and vintage organic distortion.

Housed in a solid American mahogany cabinet with a hand-rubbed cherry finish, the Formula 21 combines classic tube aesthetics with modern studio-grade connectivity for direct recording and live sound reinforcement.

Tech 21 Private Stock Formula 21 Front View Formula 21 Rear Panel and Tubes
Limited Production / Custom Batch Order
Multi-Channel Analog Workstation

Blonde Deluxe SansAmp Character Series

A limited Private Stock execution integrating pure all-analog signal paths with convenient digital preset recall. Features 6 programmable channel locations, dual instrument inputs, and a programmable FX loop designed for versatile stage and studio performance setups.

Delivers authentic American amplifier voicings — spanning sparkling clean tweed, punchy mid-range bark, and saturated full-bore tube overdrive with immediate foot-switchable preset switching.

Tech 21 Blonde Deluxe SansAmp Preamp
Limited Collector's Batch

Formula 21 Technical Architecture & Control Specifications

Vacuum Tube Circuitry: Powered by dual hand-selected, low-noise 12AX7 preamp tubes operating at high internal plate voltages.
Hardwood Enclosure: Precision handcrafted solid mahogany cabinet with furniture-grade cherry oil finish.
3-Band Passive Tone Stack: Passive EQ network modeled after vintage studio consoles providing up to 6dB of smooth frequency cut.
Active Presence Control: Active upper-harmonic filter centered at 2.5kHz with +6dB boost capability for edge and clarity.
Proprietary Character Filter: Tailors bass contours — engaged for deep low-end thump and crisp highs, or bypassed for flat Jaco-style response.
Interactive Bright Switch: Dynamically enhances high-frequency detail relative to the Drive gain structure setting.
High-Z Input (1MΩ): High-impedance input optimized for modern active pickups or traditional passive bass instruments.
Studio Direct XLR Output: Balanced XLR output with switchable Line/Instrument level matching and Ground Lift isolation.
Boutique Orders & Global Wholesale

Custom Batch & Professional Audio Inquiries

Whether you are a international distributor, audio equipment importer, touring professional, or boutique hardware buyer seeking limited-run custom gear, contact Tech 21 NYC directly for specs, custom batch availability, and global pricing options.

Get a Quote