As we all know, the Internet of Things is full of various modifications you can apply to vintage Marshalls. The small problem I’ve noticed is that the same mods are recycled over and over again. It’s hard to find truly unique approaches.
Now, generally speaking, a Marshall amplifier is not rocket science, and there’s only a finite number of things you can do with this design. In this article, I aim to contribute something relatively original to the family of Marshall amplifier mods.
But first, let me give you some backstory. A couple of years ago, I received an amplifier for servicing from a guy who’s the frontman of a well-known band around here. He used to play a Mesa Boogie Rectifier but, at some point in his career, came across a peculiar Marshall JCM800 2204 that had been modded somewhere in Germany.
This amplifier didn’t sound much like a traditional Marshall. Instead, it was absurdly fat and greasy, with exorbitant amounts of gain. In my opinion, it had far too much gain—you had to keep the Gain pot below halfway. After 12 o’clock, the amp would become unstable. Despite these "cons," by keeping the gain lower, the amp became a fiery ball packed with rock ’n’ roll.
I took a look inside this amplifier and noticed it was one of those designs where the cathode follower stage had been removed. That half of a 12AX7 was repurposed to implement a standard common cathode gain stage. Later, I discovered that Reinhold Bogner used this style of mod for some players back in LA.
It didn’t take me long to connect the dots—Bogner, being German, and this 2204, modded in Germany—this type of mod might have a nationality. Seriously, I suspect there was an old tech in Germany who developed mods like this, and Bogner either adopted it or perhaps even originated it. But does it really matter? No, it doesn’t. It’s a logical modification to make to a circuit and a fantastic way to achieve more gain.
But how important is the cathode follower in a Marshall circuit, really? As some of you may know, my philosophy is that—what? Everything makes a difference. And the cathode follower does a great deal in a Marshall circuit. It completely changes how the tone stack responds and affects the feel under the fingers, at least to me.
I consider having a cathode follower-buffered tone stack or a non-buffered one to be a very important design choice in every amplifier. And what I know for sure is that some people like it, and some don’t. We’re not really talking about whether it’s better or worse without it—it’s definitely different.
