Marshall Amps: History and Design

Marshall Amps Origin

• Marshall is a British brand and a well-known pioneer in amp design and manufacturing.
• The amps are essential to the sound of bands like Iron Maiden and AC/DC and guitarists like Slash, Gary Moore, and Angus Young.
• The company was founded in London in the early 1960s by drummer Jim Marshall and his son Terry.

Early Days and Influences

• The shop catered to rock musicians, unlike other instrument stores that catered to jazz.
• Young guitarists voiced concerns about the lack of punch in existing amplifiers at the time.
• Jim Marshall began producing amps based on the Fender Bassman, which was popular among guitarists seeking a powerful sound
• The Fender Bassman was originally designed for bass.

Design Innovations

• Marshall kept the Bassman's circuitry but used 5881 power tubes and an ECC83 tube for added gain.
• ECC83 tubes are also known as 12AX7, unlike the 12AY7 used in the Bassman.
• Marshall separated the amp and speakers for better transport.
• Marshall amps used 12-inch Celestion speakers in a 4x12 cabinet.
• Fender Bassman amps used four 10-inch Jensen speakers.
• Marshall closed the speaker cabinets' backs for a punchier, more aggressive tone, unlike open-back Fender amps.

JTM-45

• In 1962, Marshall amps released the JTM-45, named after Jimmy Terry Marshall and outputting 45 watts.
• The JTM-45 quickly gained popularity and became the base for later models.
• Marshall released its first combo amp, the Bluesbreaker, in 1964.

Bluesbreaker

• The Bluesbreaker used KT66 power tubes instead of the 6L6 tubes commonly used in the United States.
• The Bluesbreaker amp had tremolo and could fit in a car trunk.
• Eric Clapton requested the amp when he was in John Mayall's Bluesbreakers.
• Original Bluesbreaker amps are now highly sought after by collectors.
• Initial price was half the price of a Fender Bassman and a third of a Vox AC30.
• Current reissues of the Bluesbreaker cost around 1800 euros.

Super Lead 1959 "Plexi"

• Pete Townshend wanted more powerful amps, leading Marshall to design the 100-watt Super Lead 1959 in 1965.
• The amp was nicknamed "Plexi" due to its plexiglass front panel replaced in 1969 with a gold aluminum panel.
• The "Plexi" amp era created a distinct high-distortion sound emulated by other amp and pedal manufacturers.
• Super Lead 1959 defined the sound of rock.
• An iconic rock image was born when Marshall made 8x12 speaker for Pete Townshend which led to using two 4x12 cabinets stacked.

Evolution of Marshall Amps

• Marshall started using EL34 tubes in 1966 due to the high cost of KT66 tubes.
• EL34 tubes became characteristic of the brand and provided more aggressive, high-gain tones, distorting more easily.
• The JCM-800 series, introduced in the 1980s, was essential to the sound of hard rock and heavy metal bands.

Later Series

• The Silver Jubilee series, released in 1987, commemorated Marshall's 25th anniversary.
• JCM-800 series was the base, and used a switch to reduce output.
• The JVM series were designed to be versatile and have four footswitchable channels.
• The JVM-410h is a 100-watt amp with configurable channels controlled via footswitch

DSL Series

• The DSL series is popular for offering classic Marshall valve tones at affordable prices.
• DSL series is versatile for home use to professional applications.
• DSL amps have two channels with different saturation ranges, controllable via footswitch and integrated reverb effect.

DSL Models

• The Marshall DSL1CR is a small amp with an 8-inch Celestion speaker.
• The DSL1CR has ECC82 and ECC83 valves, two channels, reverb, EQ, effects loop, footswitch, and switchable wattage from 1 to 0.1.
• The Marshall DSL5CR has two ECC83 valves and one ECC99 also known as 12BH7 with switchable wattage from 5 to 1 watt.
• The Marshall DSL20CR has three ECC83 valves, two EL34 valves, a 12-inch speaker, and 20 watts of power.
• The DSL20CR is best suited for band practice and small live shows but can be used at 10 watts.
• The Marshall DSL40CR has 40 watts switchable to 20 watts.
• Marshall DSL 100HR is a 100-watt head.
• Other DSL head models are available at 20 watts and 1 watt.
• DSL amps are made in Asia.

Origin Series

• Origin series is affordable and goes back to the original sound of Marshall without excessive distortion.
• The Marshall Origin 20C has 20 watts switchable to 3 watts.
• There is also one that can switch to 0.5 watts.
• The Marshall Origin 20 C has three ECC83 preamp valves, two EL34 power valves, and a 10-inch speaker and costs 500 euro.
• It has a 50-watt version with switchable 10 and 5-watt options and a 12-inch Celestion speaker.
• Head versions of 50 and 20 watts also exist.
• Jim Marshall, known as "the Father of Loud," changed music history with his amps.