I ended up getting the Betchtec rather than the Jucedlink and think I may of made as mistake. It does not put out enough power to allow me to turn off all the pre-amps in the camera (works with just Analogue however) and it goes through a 9v battery every 2/3 hours (using 2 phantom power microphones).
I am wondering if I should sell the Beatchtek and buy a Jucedlink so have a couple of questions for any Jucedlink users out there. If you are kind enough to answer can you let me know what camera you use and if you use ML (Magic Lantern) and if so do you use latest version.
So if you turn off all the preamps (I guess you need to use something like ML to do this) does the Beachtek push out enough signal. I have been told by Beatchteck it can do 15dB and Jucedlink site mentions '30dB low-noise typ max gain (single ended, stereo)', what is single ended stereo?
Secondly how long does the battery last in the Jucedlink (with 1/2 phantom powered mics)?
Lastly, Beatchteck bloke said 'I believe that this (Magic Lantern) firmware upgrade may be reducing the gain of the camera severely which is why you are not getting enough level.', does this make any sense?
I don't know if this will help you or not, because I don't use the 550D or Magic Lantern... but I use the Juicedlink DT454 and I get plenty of amplification. I usually only have to turn the gain halfway up on the Juicedlink to max out the audio meters on my GH2. The GH2 does not allow the internal preamp to be turned all the way off, but I do turn the gain down to the lowest it will go. I'm very happy with the audio I have recorded in-camera using the DT454. I not sure on battery life because my mic has it's own battery, so I don't use phantom power on the DT454. My guess is that power consumption would be about the same, though. I do wish the Juicedlink had an AC adapter.