All Tube Circuit
The NT2H Lil' Night Train featured a three tube circuit.
The signal from the input jack was connected to V3a, the first half of a 12AX7 (ECC83) tube, the initial gain stage. The "Bright / Thick" switch then routed the signal from V3a either to the "Top Boost" tone control circuit ("Bright" position) or directly to V3b, a second gain stage ("Thick" position).
The preamplified signal then proceeded to V2, a second 12AX7 (ECC83). V2 served as a phase inverter or "splitter." The phase inverter circuit converted the single audio signal coming from the preamp and tone controls into two individual signals that are out of phase with each other. Each of these out of phase audio signals supplied one half of the output amplifier stage.
The signals from the phase inverter were directed to V1, a 12AU7 (ECC82) dual triode tube. While it would be more conventional to find a 12AU7 in the preamplifier circuitry of a guitar amplifier, Vox used it to power a 2 watt "push - pull" power amplifier stage in the NT2H. One triode of V3 powered the "push" side of the power amp, the other half of V3 powered the "pull" side.
Like the Night Train that preceded it, the Lil' Night Train featured a unique, all metal two piece enclosure. Vox catalog literature described the enclosure as resembling an "armored lunchbox."
The printed circuit board and electronic components were mounted in the lower portion of the enclosure. The control panel nomenclature was silk screened directly to the chassis.
The chrome plated upper portion of the enclosure provided ventilation for the transformers and tubes through perforations cut in the steel case characteristic to the diamond pattern of Vox grill cloth.
This imaginative, all metal enclosure design eliminated the additional cost, size and weight of a traditional wood head cabinet. At less than 9" wide and under 5 pounds, the Lil' Night Train was ready to go anywhere.
In addition to Gain, Treble, Middle, Bass and Volume controls, the NT15H Night Train included a "Bright/Thick" switch. The tone control circuitry was bypassed in the "Thick" position which in turn added extra gain to the preamplifier.
Vox designed the V110NT enclosure to accompany the NT2H Lil' Night Train head. The compact closed back enclosure included a single Celestion/Vox VX10 speaker and ports to increase bass response.