Tech 21 Double Drive

The Tech 21 Double Drive is a distortion pedal from Tech 21 that captures the power amp distortion of two different tube amp output stages and runs one into the other. Instead of blending two amp voices side by side, the signal path of Drive A feeds into the signal path of Drive A/B, which Tech 21 describes as an electronic multiplication, rather than addition, of the amount of distortion, for a cascading effect¹.

The pedal was first introduced in 2002 and discontinued in 2006². Tech 21 reissued it in 2026 as a limited edition, available exclusively through the company's Reverb shop².

Two cascading power amp distortions

Most two-channel drive pedals let you switch or blend between voices. The Double Drive's trick is that its two distortions are in series: Drive A's signal path runs into Drive A/B's, so the gain of each stage compounds. Tech 21 says the result is massive "cascading" distortion and limitless tonal variation, with the best characteristics of each amp blending to create original tones¹.

Each drive is modeled on a different power amp output stage:

¹⁴

The harmonic content is not static. Tech 21 says the amount of harmonics is dynamically controlled by the input level, and their ratio by how hard you pick¹. Barry Rudolph's independent writeup makes the same point: Drive A yields Class A distortion with mostly even harmonics, while Drive A/B provides Class A/B distortion rich in odd harmonics⁴.

Either distortion can be used individually or together in cascade⁴. The pedal also has practical input and output stages: an ultra high impedance 1 megohm input that won't load your guitar's pickups, and a 1kOhm output impedance for driving long lines without loss⁴.

The controls

The control set is small, and each control does a lot:

¹⁴⁵

The Tone control is unusual. Rather than a standard treble cut, it shifts the center frequency of a high-cut EQ across a wide range, from 10kHz down to 1kHz⁴.

With both Drive controls at minimum, the pedal works as a clean boost of up to 10dB⁴. Tech 21 described the 3X version's Level control as useful as a pre-boost for additional gain out of your amp without altering tonal characteristics⁵.

History and versions

The Double Drive was originally released in April 2002³ and discontinued in 2006². It came in four colors: black, yellow, blue and red². JHS Pedals notes the black version is the easiest and cheapest to find on the used market³.

The JHS writeup also makes a broader point about the maker: "when you hear about Tech 21, all you really hear about is SansAmp stuff. For the record, they also make amazing drive pedals"³. The writer adds that the Double Drive had been on his board cumulatively for three years of his life³.

Double Drive 3X and the Private Stock MOD

Tech 21 later built the Double Drive 3X, which keeps the same core topology: the signal path of Drive A runs into the signal path of Drive A/B, an electronic multiplication rather than addition of distortion⁵. It runs on a standard 9V alkaline battery (not included) or the optional Tech 21 Model DC4-A power supply⁵.

In 2011, Tech 21 released the Double Drive 3X Private Stock MOD at an MSRP of $215.00⁶. Premier Guitar's press release described it as offering two different types of distortion that can be used individually or cascaded together, each based on the power amp output stage of specific tube amplifiers, with an active 3-band EQ among its other features⁶. The MOD was revoiced for more hard rock and metal tones rather than classic, bluesy-style tones⁶. Tech 21 later offered the 3X MOD at the same price as the original for a limited time⁵.

The 2026 reissue

In May 2026, Tech 21 reissued the Double Drive as a limited edition, available exclusively through Tech 21's Reverb shop². The reissue is 100% analog and captures the same Class A and Class A/B power amp distortion, with one feeding into the other for cascading distortion². It is available in a black finish only, at a street price of $225².

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