Sound City output jack wiring

[Gaz]

Can someone please explain what's happening in this output jack arrangement? It's very puzzling! Thanks.

[Jazz P Bass]

The jacks are all short circuiting the output transformer if no speaker is connected.
(This will save the OPT if nothing is plugged in, through ignorance or an equipment malfunction)

The four jacks are wired as Group A & Group B.
The two on the left can be considered Group A & the two on the left can be considered Group B.
You must connect two cabinets of the same impedance, & do the parallel configuration math to find out which tap setting to use.
Either jack in each group can be used as long as one from each group is used.

I think this arrangement is a throw back to speakers of the day that could not handle the full wattage of the amp.

Q16 covers all of this on this link: http://soundcitysite.com/faqs.htm

[J M Fahey]

Agree.
This is a big 200W amp, and typical 4x12" cabinets couldn't reliably handle much more than a 60W amp, so you needed 4 of them for this beast.
So they provided for some protection against drunk/stoned stage assistants forgetting to plug some.

[olddawg]

So they provided for some protection against drunk/stoned stage assistants forgetting to plug some.

Hey! I resemble that remark! Lol...

[J M Fahey]

I remember going on tour with Nationally known bands, where the routine was "a City a day".
The band show would be, say, from 10PM to midnight, then they would party, whatever, go to sleep 6AM, wake up next day, travel to the next city, "test sound" around 5 pm , repeat day after day.
Many chose not to do so, but they *could* rest well, sleep in a cozy bed (although usually not alone), eat well, take hot showers, etc. if they wanted.
The stage assistants stayed on stage disassembling and packing everything, loading trucks, traveling in them to the next city, straight to the next venue, unpacking and assembling everything again so at 5 PM sound could be tested again.
Sleep? .... whatever they could manage in the back of loaded bouncing trucks.
No wonder they looked/were tired as dogs, complained, and the Producer called them: "hi guys!! .... "breakfast" is ready .... "
He offered them little bags with some kind of white dust.
Probably sugar for their coffee or something, because they looked quite energetic afterwards.