featured a preamplifier section very similar to a JCM800, and a particularly sweet-sounding output section. These amps were actually used on record by Billy Gibbons of ZZ Top, and are now in some demand. The 1990s JCM900 In the 1990s, Marshall updated its product line again with the JCM900 series. Reviewed by Guitarist magazine in the UK and given the line, "Shredders, here is an amp you won't need to have modified", this move by Marshall was again an outgrowth of musicians' desires, featuring more distortion than ever and retaining popular aspects of the late JCM800 models. However, despite such marketing claims they were not as hi-gain as advertised, and used solid-state components for much of the distortion in some models - something which many guitarists did not like. Still, if not with shredders, the JCM900 line was well received by younger players associated with pop, rock, punk and grunge which was widespread by the early 1990s. There are three different variants of the JCM900. The most common models are the 4100 (100 watt) and 4500 (50 watt) "Dual Reverb" models, which are a descendant of the JCM800 2210/2205 design. These models feature two channels, a largely solid-state preamplifier, and diode distortion. The 2100/2500 Mark IIIs are essentially JCM800 2203/2204s with added diode clipping controllable via a knob on the front panel and an effects loop. These are fairly uncommon and were not in production for long before being replaced by the 2100/2500 SL-X, which replaced the diode clipping from the Mk III with another 12AX7/ECC83 preamplifier valve. These are easily the highest distortion of the three variants. A number of these were shipped with Sovtek 5881 valves, a ruggedized variant of the 6L6 family of output valves, due to a lack of suitable quality EL34s. Most of the JCM900s and 6100s built between 1994–1998 left the factory with the 5881s. Around this time, Marshall released a few "special edition" amplifiers in this range, including a "Slash Signature" model, a first for the company. This was actually a re-release of the earlier Silver Jubilee 2555 amplifier, with identical internals, a standard Marshall look, and a Slash logo. This amplifier retained EL34s and 3,000 units were produced from 1996 to 1997. 30th Anniversary 6100 series 1993 marked 30 years in the amplifier business. To commemorate this milestone, Marshall released the 30th Anniversary series of amplifiers, the EL34 powered 6100LE with commemorative