I bought this amp last month at a local Music-Go-Round store.It's the first version of the 5005 Lead 12,the one with no outputs on the front.I had been looking for one for a while. The difference between this and later versions of this amp(those have 1 or 2 outputs on the front) is that this one has a built-in Fuzz circuit that kicks in when you turn the gain knob past 8.5. You can find them on ebay sometimes but I wanted to find one locally. Below is some info about this amp. From Vintage Guitar Magazine: "Lead 12: The Little Screamer - Greater distortion at low volumes was also the goal of one of the most interesting amps Marshall released in the early '80s - the model 5005 Lead 12. A 12-watt transistor practice amp with a 10" Celestion, it retailed for under $200 and for many came surprisingly close to capturing the great, warm sound of the distorted Marshall amps of years gone by. It was a favorite of many working musicians, including luminaries like Billy Gibbons of ZZ Top. The Lead 12 proved to be enough of a hit with consumers that Marshall has continued to make transistor mini-amps. The '80s and early '90s saw the introduction of the tiny one-watt MS-2, the popular 3005 solidstate Micro-Stack (based on the 5005), and the 10-watt 8001 Valvestate Micro-Stack (part of a series of Marshall amps launched in '91 where all models with 40 watts or more used a 12AX7 tube in their preamps, to drive a solidstate power stage designed to sound and feel like an all-tube power amp), as well as numerous more high-powered combo amps, and even separate transistorized heads." From "The History of Marshall" by Michael Doyle "...Naturally there are many modern Marshalls that can come close to approximating the Bluesbreaker sound but the most surprising one is the old 5005 (Lead 12) solid-state combo so beloved by Billy F Gibbons. He recorded such guitar greats as "My Head's in Mississippi" with this amp, and I am eternally in his debt for bringing it to my attention!." I used to have the 2nd version of this amp(single output jack on the front). But that one didn't have the built-in in fuzz circuit that the 1st version has.