I have an AT822 stereo mic on my camera, and I need a way to take the stereo XLR output and send it to the two mono female XLR ports on my Beachtek. A 6" cable would be too short.

Will this work?: Amazon.com: Monster MCL FX2MX Female XLR to Dual Male XLR Y-Adapter: Marianne Faithfull: Electronics

The specs don't mention "stereo" anywhere, so I'm wondering if it just duplicates the same mono signal to both male xlr's?

If the AT822 XLR has five pins, then this is the cable you want:
Sony 5-Pin XLR Female to 2 3-Pin XLR Male XLR Audio CCXA53//A

Thanks, but it has 3-pin output ...which led me astray until I thought about that a bit more.

On reflection, I'm sure the cable I linked to won't work. The AT822 comes with a stereo 3-pin female XLR to dual male 1/4" phono splitter cable, so my easiest option is probably to buy a couple of phono-to-XLR adapters. It's a rather bulky solution though, especially as the included cable is way longer than I need.

So if anyone has a direct mic XLR to Beachtek XLR suggestion I'd still be interested.

Thanks, but it has 3-pin output ...which led me astray until I thought about that a bit more.

On reflection, I'm sure the cable I linked to won't work. The AT822 comes with a stereo 3-pin female XLR to dual male 1/4" phono splitter cable, so my easiest option is probably to buy a couple of phono-to-XLR adapters. It's a rather bulky solution though, especially as the included cable is way longer than I need.

So if anyone has a direct mic XLR to Beachtek XLR suggestion I'd still be interested.

Careful, it's 1/4" phone, not phono. Phono is an RCA pin connector, a different critter altogether. The 822 comes with two cables stock, one is the XLR-F -> dual 3.5 mono TS mini with 1/4 adapters, but the other is an XLR-F to conventional 3.5 TRS stereo mini. Since the purpose of the Beach is to adapt an XLR mic to plug into a TRS mini mic input, using the Beach for that particular mic is redundant since it already has the appropriate connector on one of its stock cables, no Beach needed.

The purpose of the Beachtek is to provide headphone monitoring and a physical level control dial, both of which my GH2 lacks.

The wiring for the cable you want is quite simple, but it seems likely that it is not sold commercially. It is easy to make if you have soldering skills, I have made 2 or 3 myself. Or you can have a place like Redco make one for you at probably no greater cost than buying a Monster cable at Amazon.

Redco Audio - Custom Audio Cables - Recording Studio Supplies - Custom A/V Panels - Design Your Own Custom Cable (http://www.redco.com/shopdisplayproducts.asp?id=126&cat=Design+Your+Own+Custom+Cable)

Great link - thanks! (Priced it at $36, in case others are interested.)

Just be careful that you never use that mic with a mixer that supplies +24/+48 v phantom power. That mic is powered by an internal 1.5v AA cell, and the manual specifically warns that external phantom voltage wiill damage the mic!

And of course outputs from that mic will always be unbalanced, unless you use some sort of adapter with an inline audio transformer in each channel to convert to balanced.

If you really plan to use that type of mic with a mixer having balanced inputs, the AT-825 would be a better choice. (Although I think both the 822 and 825 are now discontinued.)

Great link - thanks! (Priced it at $36, in case others are interested.)

The price depends on the cable type, length, and connector options you select. I got a price of $23 when I tried a 2-foot cable.

NOTE!: Be sure to tell them how to wire it properly! The "common" wiring for a Y-cable is NOT what you want for this application. As Mr. Miller observes, this is an unbalanced connection because of the microphone. So you want pin 1 on all three connectors tied to the ground/shield/screen. And pin 3 of the two male connectors also ties to pin 1/ground. Then pin 2 of the microphone connector (female XLR) goes to pin 2 of one of the output (male XLR) connectors, and pin 3 of the mic connector goes to pin 2 of the OTHER output connector.

Richard, you're entirely correct. That is the necessary wiring to make this all work.

And Graham, just remember that even that correct cable will NOT protect your mic from phantom power coming from the mixer/recorder.

Greg and Richard, thank you for your replies.

Obviously there was a bit more to this than I first realized, and while I would be fine with the wiring, the risk of unintentionally sending 48V to the mic is making me rethink this plan. AT825's are cheap enough on EBay that I think I will try to get ahold of one of those instead.

If you get an AT825, the standard 5-pin XLR to two 3-pin XLR cable was 5 meters long. You could have a shorter custom cable made, or you could order the standard cable that came with the AT835ST stereo shotgun. That cable was 24-inches long, but as far as I know didn't have its own part number.

That 5-pin variety is very common for most (all?) stereo microphones and other single-XLR balanced stereo applications. I have ~1000 feet of 5-pin mic cable just for applications with stereo mics (and coincident pair discrete mics with my adapter).