HA4700 output into another headphone amp?


Hey all;

I have a Behringer HA4700 as my main headphone amp here in the control room.  I have it connected running from each of the 4 direct outs on the back to the 1/4" plugs on the snake to the breakout box in the tracking room.  Typically, then, I'd plug headphones into the four 1/4" jacks of the snake.  So far so good...

My question....

To get more outputs in the tracking room, I've grabbed another headphone amp from another brand that a friend was getting rid of.  It specifies the maximum input level as +18dBV.

Can I connect the new headphone amp to the snake in the tracking room without wrecking anything?  

I looked in the manual for the HA4700 but it doesn't give any information about the output levels I'd be potentially sending INTO the other headphone amp.