Hey all - I have a Lindell 503 power chassis. I have been using a Phoenix DRS1R Preamp in the first slot for about 5 months now, no issues. I recently got an A designs P1 as well. All was fine, then after a couple days, I got allot of electrical hum happening, much above the noise floor of the preamp. I swapped the two modules around in various slot combinations, only to find than either module hums when in slot 2 or 3(closer to the power output). Here is the very interesting bit: If I have a condenser plugged in and turn on phantom power - the noise goes away completely. As soon as phantom is disengaged, it comes back. Now, without any mic plugged into the chassis, this phantom power trick doesn't work -the hum remains... I have made sure the IC connectors ground is intact - I have also checked and found that the ground of the IC is continuous with the XLR shields. Here is the noise. https://app.box.com/s/4ecd95c1db773cd16229 These tests are all done with a mic connected and without a mic cable connected to the input at all. I'm going via XLR output on the chassis to TRS balanced input line level on a Roland Octa Capture. Any clues?