Thanks for all the comments guys. It gives me some clarity on the various issues involved and possible options. From the sound of it no harm would be done by experimenting with using both sets of preamp outs simultaneously. Whether it will be beneficial, we shall see.
I emailed the manufacturer on this topic after hearing from a few of you as well and will let you know what they have to say.
I emailed the manufacturer on this topic after hearing from a few of you as well and will let you know what they have to say.