You’ve never heard a bass amp like this before


The options for quality tube bass amplifiers are getting more limited each and every day. Most modern production bass amps lack the deep, responsive tone that every bass player – including ourselves – searches for. We couldn’t find that tone anywhere we looked, so we built it ourselves.

When we spent three years designing the Undertow 300 we sought to create the ultimate tube bass amp. We weeded out the endless options and gimmicks that flood the bass amp market and included just the right set of features to help shape the big, harmonically rich tone that our Undertow 300 is known for. Our all-tube circuitry, coupled with custom-designed transformers from Mercury Magnetics give the Undertow 300 the punch, dynamics, and warmth that other modern amps are missing. With an optional tube-driven balanced DI output, designed in conjunction with Bill Whitlock, President of Jensen Transformers and considered one of the pioneers of balanced audio lines, the Undertow 300 can easily fit any player’s needs – from small clubs to massive arenas. Whether you prefer high-headroom cleans or an amp that growls and grinds, the Undertow 300 has your tone covered.

In the end we built an amp that WE wanted to play – hand-wired, point to point, and using the finest components available. The tone is unmatched and unmistakable, and the reason it has already graced stages around the world, used by artists from all genres and styles. The Undertow 300 is the tube amp that every bass player has been searching for.

Undertow 300

Undertow 300 Pricing


Headshell – $3,795
Tube-buffered DI – +$195
Buffered effects loop – +$95

Please Email us at for pricing and availability.

Technical Specifications


  • Single channel all-tube bass guitar amplifier
  • Over 300W of power
  • Available as a head only
  • Custom designed Mercury Magnetics transformers
  • External bias test points and controls for rapid power tube changing
  • Tube configuration: 4-KT88, 1-6V6, 2-12AX7, 1-12AU7
  • Power tubes transformer driven with a 6V6 power tube for maximum output and punch
  • Fan cooled power amp for maximum tube life
  • Impedance switch selecting 2, 4 or 8 ohm output taps, with two parallel outputs, and one 1/4″ unbalanced line-out (main outs are one combination Speakon/1/4″ and one 1/4″ TS jack)
  • Controls include: 0dB & -15dB inputs (for active/high output pickup bass guitars), Gain, Bright Switch, Treble, Midrange, Bass, Active Mid, 5-Way Mid Frequency Switch, Bass, and Master Volume
  • Jensen transformer-balanced XLR direct-out and buffered effects loop available upon request
  • Completely hand-wired using point to point and eyelet board construction techniques
  • Dimensions (L,W,H): 25″ x 12″ x 10″

Interested in purchasing this piece? Email us at to place your order.