Thanks Dr. C,
Mijares was as nice of a guy as Bruce Springsteen. Mijares was down to Earth and a really cool to hang with. No attitude and/or ego.
We didn't bring the truck to Mexico City. We set up in the sound company's equipment truck. Once the PA was installed into the TV studio, local crew set up a plywood wall across the back of the truck body doors as per my advance recommondation. The wall had an access door and air conditioning install. The recording was done via a portable system provided by one of the local studios. I also brought some goodies from the States
Back in the late 70s, early 80s, we had a similar configuration as you're doing today. We used four 19 pair snakes but not because of budget concerns. The 19 channel snakes were easier to work with plus they can be split up around the stage just like sub snakes without needing to patch the sub snakes into the main snake. Sometimes one snake went to FOH for audience mic'ing. another for the backline, another for the front line mics, yet another for an openning act, etc., etc. Cable damage was also a consideration.
Today the expando truck has three MASS W4 56 pair (music)snakes and eight DT12 12 channel (TV audio) snakes for similar uses as in the old days, just a lot more channels options. The three music snakes are set up as an A and B stage and a House band or Auxilary stage snake. The TV audio snakes are set up as four mic/line input snakes (48 channels) to the broadcast board and the remaining four snakes are set up as 24 output sends and 24 input returns as needed.
When an power isolation transformer is used, you
float the Neutral. That is, you're creating your own neutral via the transformer's center tap, so you need not use the venue's Neutral. We have a single phase isolation transformer, so we only need two hots and a ground. This keeps everything ultra clean in the truck. No crap on the Neutral to mess with your system.
Balanced power units are another fine way to deal with this issue. There's an old thread about this...
Click here