The easiest way is to get a 2 x female microdot to 3.5 mm jack Y-cable made. There are also a number of DPA accessories that'll do the job, but you will have to find them used or new, old stock as they are no longer in production. These include the MMA-6000 pre-amp, the MMA-A digital interface, and the MPS-6030 battery box (there are other variants of the battery box, but the 6030 has a 3.5 mm jack). There may also be some options from small makers, such as Church, that have made microdot pre-amps and battery boxes. You could also get two of the phantom adapters, but that will require a P48 power supply, pre-amp, or recorder.