not much, maybe 1-1.5 hours. You are getting excellent runtime, guess the flash saves a good amount of power over the INHDD.
If you are looking to reduce your bag, adding a preamp would not reduce what you have to carry incl' the power for the preamp.
If you want to increase your runtime you could easily get 20-50 hours of runtime w/ a few batteries and a dummy cell.
What are your goals for your rig?
Thanks for the response Fozzy.
Don't quote me on the 8 hours. I'm not sure on that. It's a very rough estimate extrapolated out based on my 'burn rate' over the last couple shows that I've run. However, after running for a solid 3.5 hours, I was still plenty shy of halfway empty, so that's what I based the 8 hours on. I'm sure that battery voltage drain probably isn't linear.
Regarding answering your questions, my query had nothing to do with decreasing bag weight. My goal right now is getting the best sound out of my rig, so I'm testing out Ska's M148 for awhile and then hopefully sometime soon I'll get the Aerco and see how that compares...then I'll settle one one or the other and keeps whichever sounds best to my ears. Then it will be nice to have the option of running with either the external preamp or SD702 internal preamp.
The reason I asked the question is that festival season is coming up and I'm pretty sure I'm gonna be going to Langerado next month. So, I'm anticipating what I'll be needing for juice and how much recharging I'll need to do.
Anyhoo, thanks again for the feedback.
Steve