Andrew Barta started Tech 21 with a product he originally designed for himself. Being a constant tinkerer, there are times he is inspired to build creations for his own enjoyment that are outside the realm of being mass produced and commercially viable. With the encouragement from a select few who have witnessed some of these products, Andrew has decided to open the door to his Private Stock. Our Private Stock division will offer a diverse range of products. Each product will be custom-designed by Andrew, hand-built, tested and tweaked at our factory in the United States, and available directly for purchase on a per order basis. If you are interested in these unique and limited products, we recommend checking our website periodically for updates.
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Private Stock Formula 21 Vacuum Tube Bass Pre-Amp

Andrew Barta created this because he was curious how the SansAmp Bass Driver would sound if he made it with tubes. It was an interesting and challenging project because certain tasks had to be accomplished in completely different ways.

Striving to capture the functionality and basic nature of the SansAmp Bass Driver, Andrew ended up with a product that is unique on its own with old-school analog, vintage sound.

For bass, in particular, most of the tone traditionally comes from the pre-amp stage of a bass amp.Therefore, you have a lightweight tube-driven pre-amp and the flexibility to choose the power amp and wattage that best suits your needs.

The Private Stock Formula 21 Vacuum Tube Bass Pre-Amp is custom-designed by Andrew Barta, hand-built, tested and tweaked at our factory in the United States. It is available direct from Tech 21 only.

Here’s a rundown of the controls and features:
All tube circuitry with 12AX7 low noise, hand selected tubes.
Solid mahogany cabinet enclosure with a cherry finish.
3-band EQ. Follows the concept of the SansAmp Bass Driver, but being tube-based, they are passive controls –cutting up to approx.6dB.
Presence.This is the only active tone control, in the 2.5kHz range, and is capable of boosting approx.6dB.
Drive. Determines the amount of drive.Gives you a saturated pre-amp tube sound with warm distortion in higher settings.
Character switch. Proprietary formula filter that warms up the bass, giving more bottom and more top end. Disengaged, you get a more neutral, “Jaco-style” sound.
Bright switch. Gives you a broader range of treble and works in conjunction with the Drive control. As you increase Drive, bright becomes less active.With a lower Drive setting, the bright is more pronounced.
1 megOhm Input. For active basses, you can compensate the sensitivity by decreasing the Drive setting to eliminate any unwanted distortion.
1/4-inch output.
XLR Output. Switchable line/instrument level to run direct to mixing console.
Ground lift.
Approx.weight: 12 lbs.

A limited quantity of the Blonde Deluxe SansAmp Character Series is available in the U.S. directly through Tech 21’s Private Stock Division. It features a combination of a warm, all-analog signal path and convenient digital recall. There are 6 program locations and dual inputs for two instruments to be on-line, ready to go. Create three custom tones for each input or use all six locations for a single instrument. And you can program the FX loop to engage your favorite effect each time a so-designated preset is selected. Super simple to operate, changes can easily be made on the fly –without having to refer to the owner’s manual. You just turn the knobs to a setting you like, double click on a footswitch and it’s saved in that channel.

The Blonde Deluxe offers the same pure American tones as its single-channel sibling. Sparkly, spanky cleans that overdrive with a satisfying low-end rumble become the punchy bark of hard-pushed tweed, maxing out in a fat sizzle of lead boosted tone. This Blonde is a wild ride through rock history.

Actual size: 9-7/8″L x 5-1/4″W x 2-1/4″H.