I remember when everyone was chasing that tone.
Big bottle tubes, 15" speaker pushed hard, 5751 in V1.
heavy strings and tube screamer for boost all had people swearing that each was the "secret sauce" for those tones
Yup, the VibroClone days, I remember them very well.
I was a member of the Weber speaker forum back then.
That topic (IIRC) had a subforum all its own and was always a busy subforum.
EveryBody was building their own 1-15" version/variant of a SRV Vibroclone.
The really funny thing about that was, a few years later, on another forum...
I remember a (very) high-end custom amp builder (very well respected) who used to post there all the time.
Any time anyone mentioned using 15's in a guitar amp, he would just
slay them with statistics, figures, and analytical data points.
That a 15" speaker, really, had
no place in guitar amplifiers. And he could prove it beyond a shadow of a doubt.
And the only people who would espouse their virtues were blowing smoke up their own ass and had drunk their own Kool-Aid.
He had pretty serious cred (I can't remember who it was, it was so long ago now)
But I found it really funny in light of the time and expense so many spent on making those Vibroclones there for a few years.
It was like a wave, like what you would call now 'gone viral' amongst a certain crowd.
Everybody had to have one, like Vibroclone mania...it was a real 'thing' to have your own 1-15" Vibroclone (VibroVerb) clone.