Joey T. writes in and says this ART USB Dual Preamp works well for adding XLR Phantom power to your DSLR. Although it's designed with some old school USB 1.1 and interfaces with a computer, it's also a portable PreAmp with XLR and 1/4" inputs. It can run completely portable with a simple 9 Volt battery or power it with a variety of external power sources. There's also headphone monitoring available too, which makes it even more functional with DSLR audio. He's currently running it directly into a Canon T2i with Magic Lantern to disable the AGC, but for 60D owners you should be all set with Manual levels. Preamp boxes not only power your microphones, but can boost gain with very little noise. This one claims to boost signals up to 48dB, but up to what point is super clean only real tests will tell. If you've been looking for a very inexpensive preamp box to power fancy microphones and clean up audio hiss, this little thing runs under $70 bucks. It would be interesting to see a real video test, but here's more specs.
From BHPHOTOVIDEO.com
Combination portable preamplifier and computer interface, housed in a compact rugged case. The unit is suitable for a wide variety of applications including remote field work to desktop/studio recording. The 2 input channels can accept either a microphone or line input and provide up to 48dB of gain.
Phantom power is available for use with condenser microphones even when running from the USB bus or any of the other powering options. Those include using an optional external power supply, or an optional internal 9V battery. When running off the battery, operational hours are in excess of 50 hours with phantom power off.
A stereo mini headphone jack is provided for monitoring and the rear level and monitor mix controls allow for latency-free recording. The monitor mix is also routed to the main outputs. The USB interface is fully compliant with the USB 1.1 specification and uses USB adaptive mode for playback and USB asynchronous mode for record.
• Portable USB interface with dual microphone preamps
• Low-noise, fully balanced XLR and 1/4" TRS combi inputs
• Preamps provide up to 48dB of gain and feature independent gain controls
• Built-in, low-noise phantom power supply
• Signal present and clip LED indicators
• Latency free monitoring with mix and level controls
• Includes Audacity recording and production software
• 3-way powering options - via the USB bus, an optional external power supply, or with an optional 9V battery
ART USB Dual Pre - USB 1.1 Audio Interface with Dual Mic Preamps