how'd they do that?

[beans-on-toast]

Hendrix used to jumper the inputs of his amps. Two or three at most. I don't know if all the amps were turned on. In the Fender stack in the pic, the only the bottom four have lights on.

With multiple amps, I like active splitters such as the one attached. Boxes were available back in the day that maintained impedance and offered isolation.

 

[Joebarnes]

Plug bass into Input 1 on amp A. Connect Input 2 to Input 1 on amp B. Repeat for all other amps. Signal cables must be used. Adjust each amps volume to match all the others. Not perfect but will at least work.

Question is why not just use a more powerful amp??

Yup that was how it was done. Why didn't they use more powerful amps? Those were the most powerful amps at the time.

 

[Bassmec]

It all moves around and gets lighter and more convenient but does it ever really move on?.
The assumption seems to be that the amplifiers where running really hard?, back then the idea was to have a huge wall of sound, look at early Grateful Dead live gigs.
Point Source then began to take over and continues to this day as the dominant culture.
Well until we started moving in reverse on big outdoor rigs with gusty wind conditions.
In that discipline the old school approach of Function One with massive walls of horn loaded enclosures is beginning to make a strong comeback.
I am lucky enough to have jammed in sound check, through a rather famous bit of bass guitar conspicuous consumption at charlton athletic football ground and an enormous bank of bass cabs (belonging to you know Who) on stage felt rather good Actually.
As for off axis response?, there was no where to stand where you aren't on axis with something loud and clear.
The unit above and its backup contains all of Richards guitar sounds recorded via real tube amps and speakers in ideal studio acoustics with awesome mic's, pre amps and compressors etc for the albums.
Kind of, Kemper, Kemper, Kemper, Kemper, Kemper Convinient. Eh that could be a hit!
This is how it works on second guitar and bass as well these days but going amp and cab free is only OK if the PA and monitoring contractor definitely isn't.

 

[Crackle]

More often than not, multiple stacks of amps on stage are stage props. At most, one or two stacks are being used. On the recent Van Halen tours, Ed has had eight or ten 5150 III heads on top of the same number of 4x12 cabs. His actual rig is behind the stage and consists of two 5150 III heads and spares. The same goes for Judas Priest in the 80s, Iron Maiden in the early 90s (ALL of Steve Harris' Hiwatt heads were empty chassis and most of the Marshall guitar stacks were props), and John Petrucci of Dream Theater. Watching the roadies wheel John Petrucci's stacks off the stage while the power lights were still on was hilarious . . . his actual rig is fully racked.

I know this doesn't answer the technical aspect of the question but it is reality.

 

[BassmanPaul]

Why didn't they use more powerful amps? Those were the most powerful amps at the time.

That comment was for the OP in the present day world.

 

[Dogghouse]

LEHLE products rule! Built like tanks. Their switches are practically bulletproof due to the moving parts being inside the units.

 

[Robroy]

Look at the vocal monitors, is there any chance they even heard them over those stacks?

The comb effect could have helped them. I'm reminded of the Bose towers (the only thing they make that I like, though it is still seriously overpriced). And I think they were based on this (the grateful dead wall of sound):

The guys on stage only hear the speakers at their level. But people in the back row hear all of them. I made my own DYI bose style towers and they were amazing - and they were old computer speakers.

 

[Robroy]

Plug bass into Input 1 on amp A. Connect Input 2 to Input 1 on amp B. Repeat for all other amps. Signal cables must be used. Adjust each amps volume to match all the others. Not perfect but will at least work.

And those old amps used the old two prong AC plugs that were reversable. So it would be fun to plug a few of them in reversed from the others. Might not matter, or it might fry something.

 

[lastnotleast]

When you see duplicate amps & speakers on stage these days, they are there as backups.
Don't want to charge the nice folks exorbitant entrance fees then make them wait for technical difficulties.

Back in the day, Tim Bogert actually played through multiple Fender Dual Showman amps in Vanilla Fudge.
On the opposite extreme, my band opened for Pure Prarie League (circa 1980) who had an unbelievably quiet stage volume.
FOH they were just as loud as any other band (except Cream & Steppanwolf).

 

[teemuk]

Look at the vocal monitors, is there any chance they even heard them over those stacks?

No. And wittness accounts of many Jimi Hendrix concerts indicate that audience didn't hear much of the singing either.

There are probably good reasons why band setups for gigs no longer resemble any of this. Now when bands throw a gig they don't have to drag in seven heads, twelve cabinets and two combos and yet we actually hear their music loud and, most importantly, clear.

 

[Munjibunga]

It's a prop.

 

[Bassmec]

No. And wittness accounts of many Jimi Hendrix concerts indicate that audience didn't hear much of the singing either.

There are probably good reasons why band setups for gigs no longer resemble any of this. Now when bands throw a gig they don't have to drag in seven heads, twelve cabinets and two combos and yet we actually hear their music loud and, most importantly, clear.

Quite so!. Nowadays it's those horny handed sons of toil, the PA hire crew and monitor team that do all that stuff and the musos just bring guitars moddeling units, clothes, makeup and hair mousse.