Marshall JCM model The amp model is from , its a 50watt 2 x el54 tubes for output, 6 RCA A12 pre amp tubes. Serial number is X Very large sice pic of the inside of the JCM For the past two decades, one name has been synonymous with the best in rock amplification. Marshall has now become a household name throughout the world as a symbol of precision acoustic engineering, to be relied on, not only for superlative sound quality, but for high performance night after night. Each amplifier chassis is constructed from a minimum of 16 S.