All of the tone – none of the weight


A design philosophy we follow at New Vintage Amplifiers is, “performance over price.” Time after time, we have seen our competitors utilize new solid state technologies to put out cheap but powerful bass amps that are light weight. We saw the benefits that these amps were providing to bass players everywhere, but we felt that nothing had yet opened up the full potential of this technology. We saw this as an opportunity to use state-of-the-art components to take a bass amplifier a few steps further. By combining our passion for point-to-point, hand-wired tube circuits with the latest solid state technology, we have managed to create an amplifier that has every ounce of tone you’d find in our all-tube bass lineup, but with almost none of the weight – the Undertow 500D.

We wanted to use the most transparent yet organic-sounding power amp possible to ensure that the warmth and dynamics of the all-tube preamp came through your speakers uninhibited. We are the first to admit that we were shocked to find that the Undertow 500D had all of the deep, clear bass and growling, gritty breakup that is present in our all-tube Undertow series, but with the benefits of a solid state power section; the amp is light-weight, has the immediacy you’d expect from a high-end solid state amplifier, and great tone at any volume. Adding our optional tube-driven Jensen Transformer balanced direct out, you have a versatile package that can even be used as a stand-alone tube bass preamp! No speaker cabinet needed!

This is our best example of the merging of vintage build quality with the newest technology available. We have created a true hybrid of vintage hand-wired, vacuum tube amplification and modern, cutting edge solid state technologies. The Undertow 500D is truly unique in the bass amplifier market, and will make you rethink what solid state technology can sound like.

Undertow 500D Front
Undertow 500D Close Up
Undertow 500D Back

Tone Samples

Undertow 500D Pricing


2U rack amplifierEmail for availability
Tube-buffered DI
Buffered effects loop
Custom tolexed 2U head sleeve

Technical Specifications


  • Single channel true tube hybrid bass guitar amplifier
  • Over 500 Watts of power in an astoundingly light 13 pound package
  • Preamplifier and Linear Power Supply are completely hand-wired point-to-point on an eyelet board
  • Available as a 2U rack enclosure with optional tolexed head sleeve
  • Laser-engraved brushed black anodized front panel
  • Custom designed Mercury Magnetics transformer
  • Tube configuration: 2-12AX7, 1-12AU7
  • State-of-the-art Class D power amp
  • 550W @ 1% THD+N, 1kHz, 4Ω
  • Features an advanced soft clip circuit with front panel indication to prevent harsh power amp clipping
  • Featuring built-in under-volage, thermal, high frequency, and over-current (shorted speaker) power amp protections
  • Frequency Response: 20Hz – 20kHz, all loads, +/- 0.5dB
  • Fan cooled power amp for maximum performance and output
  • Dual Neutrik SpeakOn output jacks
  • Self-adjusting output stable down to 2 Ohms – Unheard of for Class D bass amplifiers
  • Controls include: 0dB/-15dB switchable input pad, Gain, Bright Switch, Treble, Midrange, Bass, Active Mid, 5-Way Mid Frequency Switch, Bass, and Master Volume
  • Optional tube-driven Jensen transformer-balanced XLR direct-out allows for use as a stand-alone bass preamp
  • Optional buffered effects loop
  • Optional mute switch
  • Dimensions (W,H,D): 19″ x 3.5″ x 12″

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