YouTuber Joe Hart just posted a video discussing the correct way to dial in your EQ for a Marshall amp.
In the video below he tells us that Marshall Amp EQ sections are “passive”.
This means that no frequencies are “boosted” by turning the EQ knobs up. Instead he says think of it like this, you can turn all the EQ knobs (bass, mid, treble) fully up, and it will boost the next stage with a little more signal. Then you dial down the EQ knobs to taste.
If things are a little too dark then you’d bring down the bass, a little bright then bring the treble.
It’s really interesting to hear him dial in this amp. When he has the EQ mostly fully cranked then the sound is livelier, not compressed, more “Marshally”. But as he pulls the EQ knobs (and presence) down the amp seems to lose some vibrancy.
Great tip here from Joe Hart. Try it out and you may find that you’re breathing new life into your Marshall amp.
Here’s part two of that video, really great info: