They offered 2 independent footswitchable channels, each with their own EQ, a spring reverb with dual controls (one for each channel) and a series FX loop and a parallel FX loop. The schematics suggest they are, but you won’t find JCM800 printed on the amps. See the Marshall Amps VBA400 page for more «official» information on the VBA400 amp. Lots of info and pictures here, including a forum.
Complete schematic with 3x ECC83 & 2x EL34, 1987-01-60-02 Issue 4, (Marshall, 2003). FX-loop schematic, PCBP-00119-60-02 Issue 1, (Marshall, 2002?). See the Marshall Amps 1987X page for more information on this amp. They were introduced in 1993. Beware when replacing the original Sovtek 5881 tubes with EL34 tubes as these amps are only 3 rack units high. User manual for the IBS amps (790kB). The Mini Stack’s The Mini Stack concept was introduced in 1984. The Mini Stack cabinets were smaller 4×10″ or 2×12″ versions of the normal 4×12″ cabinets.
These high power Lead 1982 cabinets were made for the 2000 Lead head. Valvestate owner’s manual (1 MB). 8240 Valvestate, 2x 40W 2×12″ Stereo Chorus combo with reverb The Stereo Chorus models were introduced in 1993 and discontinued in 1996. Amp schematic. Each channel has individual volume and effects sends with channel 4 also having additional bass and treble knobs. Thanx to Jelle Falk. 4211 JCM800 Split Channel Reverb, 100W 2×12″ combo This amp is a combo version of the 2210 head. I’ve seen these amps fitted with 2 Celestion G12T-75 speakers. These 1960 style reissue cabinets were fitted with four Celestion G12T-75 speakers. 9000 Serie’s The 9000 serie 19″ rackmount amps were first introduced in 1989. 9001 Pre Amp The 9001 was in production from 1989 upto 1993. It was a 3 channel pre amp containing 3 ECC83/12AX7 tubes. The 1976 PA Columns were designed to be used in pairs with the 1966 Major PA amp.