Marshall Reverb 12

The Marshall Reverb 12 (Model 5205) is a highly regarded, UK-made 12-watt solid-state combo amplifier produced by Marshall from 1984 until 1991. It is famous for packing genuine JCM800-style overdrive tones and a real internal spring reverb tank into a compact, bedroom-friendly package. 

Specifications
Power Output: 12 Watts (Solid-State).
Speaker: Equipped with a British-made 10" Celestion G10D-25 speaker.
Channels: 1 Channel.
Controls: Gain, Volume, Treble, Middle, Bass, and Reverb.
I/O: Single 1/4" guitar input, Line Out, and a Headphone jack.
Reverb Type: Genuine analogue spring reverb. 

Though built as an affordable practice amp, the 12-series architecture achieved legendary status because its preamplifier circuit closely mimics the behavior of full-sized JCM800 tube heads. It handles guitar volume-knob cleanup exceptionally well, pushing from a warm, vintage blues crunch into roaring heavy rock saturation when the gain is cranked. 

The Reverb 12 became a secret weapon in professional recording studios. Most notably, Billy Gibbons of ZZ Top famously utilized these small 12-watt Marshall combos to record iconic studio tracks.