David Berning designed the original micro-ZOTL in 2000 as a low-power Class A amplifier to be an entry point and showpiece for his new ZOTL technology. It was a surprise when it developed a following as a headphone amplifier. LTA revived the circuit as the microZOTL2 in 2015, using the same PCB and similar parts, and the amp immediately found a place as a reference component in the now much-larger audiophile headphone market. In the years since, LTA introduced gradual improvements through model variations culminating in the MZ2 and MZ3.

The Velo takes everything we have learned about the MZ circuit, ZOTL, and building amplifiers, and started with a blank slate. The goal was to make the best-sounding, most reliable, and most enjoyable version of the amp that we could. We revisited the components, PCB layout, assembly procedure, and case design. We were not designing to a price point, but we wanted to remove any extra cost that was not directly contributing to those goals.

Compared to its predecessors, we have increased speed, reduced noise, reduced parasitics, and shortened signal paths. Coupling capacitors were deliberately chosen for best audio quality. Storage capacitance on the audio board has been increased, especially right next to the output stage. There is more power supply filtering for both the audio section and the control section of the amp. The control section has been redesigned with quieter components and lower power consumption, and the amp’s grounding scheme has been redesigned for lower noise and improved shielding. Output impedance has been reduced by nearly 50%.

We want the Velo to be simple to enjoy. The case is designed so that you should never have to unscrew the top cover. The tubes are fully visible and can be swapped with ease. The switch to toggle between 6SN7 and 12SN7 output tubes is on the back plate. The fuse has been replaced by a faster, more reliable, resettable overcurrent protection circuit. The front panel indicators are warm, natural light without glare.

• Amplifier Class: Class A Push-pull

• Inputs: 3 x RCA single-ended inputs

• Preamp Output:

  • 2 x RCA single-ended outputs

  • Output impedance: 50ohm

• Headphone Output:

  • 1 x 6.3mm (1/4”) single-ended output

  • Output Impedance: 1.1ohm

• Gain:

  • 13.5dB into 100ohm

  • 12.4dB into 8ohm

• Input Impedance: 50kohm

• THD: 0.19% at 1kHz, 1Vrms

• Hum: -90dB at 1Vrms

• Frequency Response:

  • -3dB: 2Hz - 100kHz

  • 0dB: 20hZ - 20kHz

• Power Consumption: 24W

• Tube Complement: 2 x 12AT7 (12AU7 tubes can also be used), 2 x 6SN7 (12SN7 tubes can also be used)

• Dimensions:

  • Width: 10in

  • Height: 2.875in (stock output tubes add 2.5in)

  • Depth: 10in (11.5in including volume knob and rear connectors)

• Weight: 6.5lbs