High Wattage – AC/DC’s Marshall amps through the years (Work in Progress – UPDATED: Back in Black era uncovered)

Hi Roe mate, good to see you here.
Yes indeed, 1959s are way more important in AC/DCs history than anything else. We actually know this
I think it may come off here as 2203s being more important than they actually were because the timeframe observed here coincides much with 2203 usage. Not very many early pics of AC/DC exist (prior to 1977 that is), so the editor here concentrated mostly on the era where AC/DC started being more in the media eye.
We probably overlooked the possibility of a Master Volume 1959 as you say, but personally, I don’t think it was used much, if ever at all. Powerage, maybe Highway to Hell and Let There Be Rock were much likely played – Angus’ side at least, though I do believe Malcolm as well at least on Powerage – with 2203s more than anything else. You know I own all those amps of that era now, and I don’t buy the “production” work too much (to “make the sound”). I think I was able to replicate fairly well some of those sounds, right off of Powerage, Highway and LTBR using in fact, 2203s.
Unless solid proof of such a rare amplifier being used appears, I think we’ll stick to 2203s for the given era/albums /mainly, 1977 to 1979, “Back in Black” reintroducing massively 1959s).

But the more there is to learn, the better: for us here this is the main objective (which is mainly aimed at replicating those very sounds as closely as possible). The only thing is, we try to base ourselves on factual evidence and “sound” evidence as well

PS Also, Roe, what was really, really decisive for us here was the discovery of the Schaffer-Vega Diversity System.
By using that system, we were able to replicate those very sounds on generic to the era Marshall amplifiers such in fact, 1959 and 2203s. At least for Angus, I don’t think anything else was used in the 1977 1980 time-frame (which has been the one we focused mainly for now, trying to debunk the various eras).
Once one learns what the SVDS brings to the sound of such Marshalls, it is easier to recognize the amplifier behind it.
Despite the fact that even in such early years AC/DC’s amps may have been modified, I don’t think these were modifications assimilable to the ones used a lot more heavily during the ’80s in general terms (hence, really changing the character of the amps). AC/DC also started modifying their amps for sure at least in 1988, which is a more or less reliable fact the source being Mr. Rick St. Pierre with whom I have been in touch with a bit lately. But earlier on, I think the amps were – soundwise – more closely sounding to their stock form than anything else