@Kapo....Polenton
Check the Rodenberg 728NG (a bit more vintage vibe, with quite a lot of Gain), still my favorite, has a hint of tubescreamer, even more gain than Xotic RC, OCD available
The Lehan Labs 2CH: (more Gain, flatter in the Midrange, very tasty modern Marshall with balls, little more aggressive without harshness)
Baldringer Dual Drive: an improved highly configural ocd kind of sound much more gain, less flappy, very transparent, cool features, kicks the ocds ass, it is actually the most neutral, clear pedal I tried, more usable gain than the Rodenberg
Fulltone OCD 4: (neutral sounding like Baldringer, less gain than above mentioned, more gain quite=>muddy, flabby, a bit neutral and less full sounding then all above mentioned
My list for improving my Marshall and getting more gain for vintage sound clearly TM Boost from Cornell
1 Rodenberg
1b Suhr Koko Boost
2 Baldringer Dual Drive Red Enclosure
2 Lehan Labs
3 Analogman KOT 4 (is a little more boxy than the above mentioned, was designed for Fenders Amps, less gain than all above mentioned.
IMHO: The Analogman Kot 4 is for Fender Amps (improving a tubescreamer midrangy sound! YOU NEED THIS WITH FENDERS) what the Baldringer Dual Drive is for Marshalls (getting much Gain with pedals without altering behavior and retain playability and not getting muddy; very transparent, very dynamic, probably kings in their classes.
The Rodenberg is something in between the two, a little more TS but more open than the KOT 4, less gain and less neutral than the Baldringer Dual Drive and more midrange.
I will make a thread of my own shortly with sound files comparing my favorites.
To the original poster:
I would try a Tonebender JMI MKII, a Treble Booster (Cornell TM Boost/or boxey midrangy Divided by 13, and a Fuzz Analogman NKT side by side, they all differ and have there virtues, I certainly prefer Germanium in all of them
Played a few hours:
Checked again the Suhr Koko Boost, right now my favorit booster, does not add harshness and retains the bass, will check furthermore...
So right now favorite Rodenberg 808 side and Suhr koko for boosting, will try it a few day more, the Rodenberg Boost does affect the bass of the original way to a certain degree, the Suhr is more natural....
Greetings
Kai