Super Foundation Bass Head
JMI Vox introduced three new solid state bass heads in 1967, the 30 watt RMS Dynamic Bass, the 50 watt RMS Foundation Bass and the 100 watt RMS Super Foundation Bass. All three shared the same two channel solid state modular preamp section and Thomas Organ inspired control panels. The Dynamic Bass utilized the 30 watt modular solid state power amp section from its guitar amp counterpart, the Conqureror. The Foundation Bass shared the 50 watt power amplifier section
with the Defiant. The Super Foundation Bass and Supreme guitar amps were powered by the same 100 watt solid state power amplifier module
A complete Super Foundation Bass amp was nearly as tall as a Supreme or AC-100. At the time it was introduced, it was the largest and most powerful bass amp produced by Vox. To celebrate its size and power, Vox nicknamed the Super Foundation Bass the "Big Daddy" in their 1967, 1968 and 1969 product catalogs.
The head cabinet for JMI and VSEL (1967-1970) Super Foundation Bass amps featured black Vox diamond grill panels on the both front and rear faces. The amps also included two horizontal "Thomas" style Vox logos, two-pin corners and a strap handle with a Vox logo. The cabinet was covered in traditional Vox basket weave vinyl with gold string accents. The earliest of these amps would have a JMI serial number plate on the rear panel. The preamp circuit was detailed on JMI Vox schematic OS/137, the power amp circuit on OS/135. These schematics are available for purchase at North Coast Music.
A second version of the Super Foundation Bass head was produced during the Corinthian and Stolec Vox periods (1970 - 1972). The front panel featured black Vox diamond grill cloth and a horizontal Vox logo. The rear panel was covered in vinyl. Eight two-pin corners and a Vox logo handle remained. Silver string replaced the gold string accents used on earlier models (see photo at left). A crude silk screened serial plate was screwed to the back panel. These later Super Foundation Bass heads utilized a revised fuzz and MRB circuit, detailed on VSL schematic OS/185.