[Jason Brooks]

I would definitely go with the 552. You can externally sync it with timecode + with direct outs for all 5 channels, you can always add another recorder.

[Jason Brooks]

This is actually a lot easier than it is. You can take a line level signal by simply engaging the PAD in the menu and taking the level to -30 db. Why? The difference between mic or line level (+4) is 50 dB. If you were to buy a inline XLR line to mic adapter that is what does is take the signal down -50 dB. The PAD setting in the transmitter is -20 dB, engaging that & taking the AF to -30 dB does the necessary padding for line to mic. If you are dealing with consumer line level (-10dB), meaning anything with a RCA or mini jack connection, you simply do the math between the 2 line levels which is 16 dB, then subtract from 50 dB. You need a reduction of 34 dB. Engaging the PAD (-20 dB) and -14 on the AF gives you a consumer line level input into the transmitter. Another solution is to have an adapter made for either mic or line level. If you open the connector for the Sennheiser, simply resoldering the + connection to the other pin will give you line level in.