The History of: JCM900


The History of: JCM900

Re-visiting a ‘90s classic – the JCM900 Series.

In the late 1980’s, guitarists were asking for more from their amplifiers. Increased gain, extra features, and reduced noise were just some of the requests from customers. Amplifier modifications became hugely popular, but ran the risk of damaging amplifiers, affecting re-sale value, and risking the legendary Marshall reliability of the amplifiers.

Enter the JCM900 series, released in January 1990. Higher gain, lower noise, reliable, and classic Marshall tone. Originally comprising of two basic models, the JCM900 series was available as the single channel Hi-Gain Master Volume MK III, and the two channel Hi-Gain Dual Reverb. Addressing some of the issues customers had with earlier Marshall heads, the JCM900 series contained a series effects loop, two line outputs, and a high/low switch – dropping the power from 100 Watts to 50 Watts, as originally found in the 2555 Silver Jubilee.

“Marshall has maintained its reputation by keeping pace with a clientele that has become younger, faster, smarter and more versatile with each succeeding generation. The Hi-Gain Master Volume and Hi-Gain Dual Reverb series continues in that grand tradition. These are not pumped-up variations on a theme. Rather they are significant steps in the evolution of an important force in contemporary music. After testing one amp from each series, I would say that Marshall has once again successfully reinvented itself” – Guitar World, February 1991.

Today, the JCM900 is still available in the Vintage Re-Issue Series as the JCM900 4100 – the Hi-Gain Dual Reverb model released in the ‘90s, re-released as a precise re-issue.

This high gain, dual reverb, all-valve 100 Watt head is still a players favourite. Known for its tone and workhorse roadworthiness, the JCM900 4100 has many fans due to its feature set and versatility.

Channel A is voiced to be sparklingly clean on lower gain settings, building to a raunchy crunch when driven harder. Channel B takes the gain higher producing tones from silky smooth distortion to searing, saturated scream.

The JCM900 4100 is equipped with a series FX Loop with its own Level control for use with rack FX or stomp boxes.

The JCM900 series is still used today by artists including Zach Blair of Rise Against and Joe Gosney of Black Peaks, who notes:

“The JCM900 is awesome. It manages to do everything an amp should ever do without the need to over complicate things.”

Find out more about the JCM900 at