roxy54 No, John Curl did not design McIntosh products, but he used for the system. He designed the crossovers, and worked with two other engineers on the monitor less dual microphone system (wired and positioned out of phase with each other to remove any feedback from the speakers behind the mics). He also provided his expertise for other wiring issues for the Dead's Wall of Sound system. There were two to four semi trucks, depending on the venue, each with sets of scaffolding. As the band played one venue, the second structure was being assembled at the next destination. Acid King Owlsley Stanley built the speaker cabinets, and JBL made many of the drivers, along with Electrovoice, I believe, abut Curl designed the electronics other than the amps. BTW, at Miami Jai Alai, about two and a half dozen 300 wpc transistor amps ran the instrument speakers, while 350 wpc tube amps were used for the singers, in order to get pleasing harmonics. Interestingly, there were no mixing boards, nor monitors. Check out the system below. I saw and heard it indoors at Miami Jai Aai, where a smaller number of amps, were used than at the outdoor stages, only a few dozen.
https://en.wikipedia.org/wiki/Wall_of_Sound_(Grateful_Dead)#:~:text=The%20Wall%20of%20Sound%20was,as....