The 4x12 enclosure used for the Westminster "Power Stak" was introduced a year earlier as a part of the Sovereign Bass amp. Each cabinet featured four 12" Vox special design gold frame speakers with ferrite magnets manufactured by the Oxford Speaker Company of Chicago IL. The cabinets featured a bass reflex vent on the back panel that Thomas Vox called the "Bass Intensifier."
The 120 watt, 240 watt peak power V1182 Westminster head, introduced in 1968, supplied the power. See the Westminster owner's manual by clicking here. The V1182 was a two channel amp. Channel one featured rotary volume, treble and bass controls plus a Top Boost switch. The second channel featured a volume and Tone-X control.
Tone X was essentially a sweepable parametric tone control electronically similar in concept to the Wah Wah pedal. When turned fully counter clockwise, the tone from the Tone X circuit was very bassy and had little treble. When clockwise, the tone was bright and thin.
A "G-Tuner" feature provided a tuning reference tone.
While impressive in stature, the V1261 Westminster Stak had an inherent design flaw. At six feet three inches tall, the narrow, 11.5" deep cabinets did not provide a stable platform for stacking. Unfortunately, a toppling Vox Power Stak provided additional drama to the performance of many using this amp. The simple tug of a guitar cord was enough to start the action.