We are not liable for damage in transit. Read that last bit again. We bear a due diligence responsibility to pack your gear properly when we ship it out and will insure the shipment for the value of the gear. In cases where we're returning gear that you shipped to us, our due diligence is limited to packing the gear only as well as you packed it when you sent it to us.
The problem is that amplifiers are both heavy and fragile combined with a tendency for shippers to employ troglodytes to handle packages. No matter how well you pack your EV loaded combo, if the shipper throws it on the ground the speakers are going to break loose from the baffle. After that, it's wonton destruction as the speaker bounces around the back of the amp. There are horror stories aplenty on the web discussing shippers destroying stuff.
Now that you're nervous I should also add that as of July 2007 we've never had an amplifier damaged in transit. Not one. If you're planning to ship something to us for service give us a call and we can help you get the package properly packed and marked as well as advise you of which shippers have the best track record.