The Circuit: Marshall Part 2, Post-Hand-Wired Amps

February 11th, 2015

Screen Shot 2015-02-11 at 1.51.47 PM

By Mitch Colby | Illustration by Evan Trusewicz

In the early Seventies, as heavier forms of rock increased in popularity, Marshall was on the rise and selling boatloads of stacks. The amp maker’s worldwide presence grew as most of the hard rock bands coming out of the U.K. and U.S. used Marshall amps to both sound great and look awesome onstage. The list of rock guitarists and bands that used Marshall amps goes on forever.

Until the middle of 1973, all Marshall amps were hand wired. As sales increased, it became a daunting task to build so many hand-wired amps, so Marshall changed production techniques and incorporated the latest printed circuit board (PCB) technology, which promised more consistency, higher quality, shorter build time, and lower costs. Unfortunately, it seems only part of that formula came true.

What’s important for collectors to know is that Marshall’s hand-wired amps are more desirable. Why? According to most players, they sound better, even though the amps have the same circuits and in some cases identical parts. More importantly, the early printed circuit boards used thin traces that can lift when parts fail and have to be unsoldered. This can be very troublesome for a tech when servicing the amp and seriously compromises future reliability.

The hand-wired amps are much easier to service because the parts are attached to either turrets or eyelets. The component leads are on top of the board, making changing faulty parts much easier than removing the PCB to get to the bottom of the board to unsolder components. As far as sounding better, there is a lot of debate on the sound of hand-wired versus PCB. One can make great amps either way. I prefer hand wiring because of the ease of servicing and modding.

Regardless, Marshall made some very good (and even amazing) PCB amps, some which have become iconic in their own right. For example, the MV (master volume) and Jubilee models sound great and have become collectible over time. Partially because of their relatively simple circuits and designs, most MV (the 100-watt 2203 and 50-watt 2204) and Jubilee (the 50-watt 2550 and 2553 and 100-watt 2555) amps have survived because they are simple to maintain and service. All they need are new tubes and proper biasing. If something goes wrong, they can be fixed by any competent tech.

It is interesting to note that Marshall sold five times as many JCM 800 split channel amps with two footswitchable channels and reverb when they were in production compared to the MV versions of these amps and 10 times as many compared to the four-hole standard versions. That goes to show that the average guitarist prefers features over tone. The JCM 800 split-channel amps sound pretty good, but their downfall was a mediocre clean channel.

Even today, many artists still use Marshall MV amps in their rigs. Marshall reissued those models because of their popularity with artists such as Kerry King and Zakk Wylde, who use these amps for their raw drive and tone but employ pedals to increase drive and to shape EQ. Most of Marshall’s original MV amps sold in the U.S. were fitted with 6550 tubes, which gave them more headroom and wider frequency response, particularly bigger and tighter bass. Marshall also reissued the Jubilee as the Slash signature model.

Other desirable post-hand-wired Marshall amps include the Artiste, which is notable not because it is great in its own right but because it is a great platform for modifications. This model should not be confused with the Marshall Artist, which was a 30-watt hybrid head and combo. The Studio 15 1×12 combo also has many fans.

Marshall has been around for more than 50 years, and it has made many good amps that have found fans as well as detractors. Other models of note include the three-channel 30th Anniversary, JCM 900 dual channel (the workhorse of many a rehearsal studio), SLX (high-gain cascaded preamp), JCM 2000 (DSL and TSL), and JVM.

Mitch Colby helped develop many Marshall and Vox amp designs and is the founder of Colby Amplification.

Want to read more stories like this?
Get our Free Newsletter Here!


Comment guidelines, edit this message in your Wordpress admin panel