 |
 |
 |
 |
 |
 |
||||
Marshall Amps |
The history of Marshall Amplifiers has become a source of great fascination and interest over three decades. In 30 years of manufacturing we have made a vast number of different models using many materials and techniques. People like Jimmy Page, Jimi Hendrix, Pete Townshend of the Who, Tony Iommi, Eric Clapton, Jeff Beck, Ritchie Blackmore are just a few of the many Marshall Amps users. Documentation from those Marshall amps early years is virtually non-existent. The pressure to build amplifiers was so great that detailed record keeping was impossible. This pressure also created anomalies in the products themselves as component and minor cosmetic changes could be phased in at any time where supplies ran out but production had to continue. The following information is a rough guide to the major changes in the most popular Marshall models since 1962. Jim Marshall made his first amp back in 62 in order for the bass guitarists to be as loud as the drummer. This was mainly for Rock music and musicians as the drummers simply played louder than that of say a jazz drummer. In fact Jim was a drummer and I'm sure he wanted to be able to hear what they were playing. He had a music store in England and sold Fender amps. His favorite was the 59' Bassman (which is actually a great sounding guitar amp). The problem as Jim found it was these amps where too expensive. He decided to make them as inexpensive as possible by limiting the 'features'. This ended up being an amp with a single speaker impedance, and very similar controls as found on the Bassman. The JTM45 was the first Marshall amp. It had 25 watts of power and a different sound than that of the Fender Bassman mainly because different output tubes where used, the KT66. It had a softer sound than that of the Bassman. Later the KT66 was replaced with the EL34 which further changed the sound of Marshalls. By adopting the EL34 meant different output transformers where used. In the beginning Marshall Amps a number of amps where designed, each to be used for a different purpose: PA (Public Address), Organ, Bass and Guitar. The JTM 45 was often used with two column type speaker cabinets for PA systems. Later when the 100 watt Marshalls where developed, many variations of the amp were used for particular purposes. The PA versions had an extra 12AX7 to allow for extra input channels. They also added two more output tubes (EL34) and larger output transformers. The early Marshall amps didn't yet have a Master Volume control. For the bass amps usually the only difference was an added capacitor placed on one of the inputs that would filter out some of the high frequencies. It was the Bluesbreaker amp or Model 1962 combo amp which really put Marshall on the map. This amp was used by Eric Clapton in the legendary John Mayall Bluesbreakers. The master volume actually came into being around 1975. With a master volume control you could overdrive the preamp tubes to get a more distorted sound without blowing down the walls. The sound wasn't like Eddie Van Halen but more of a bluesy fuzz sound. The only way to get a great distorted guitar tone was to turn up the amp to overdrive the output tubes and speakers. Celestion Speakers where used in most of these amps. They would of course vary depending upon the type of application. The Guitar amps use them in a number of different configurations, ie. 2 x 12" open backed cabinet to 8 x 12" speakers in a closed back cabinet. |
| Heads and Combo Amps | |
|
|
|
|
