Lightning-to-30pin adapter compatibility questions

Question

I'm thinking of upgrading my iPhone 4S to a 5 or 5S.  I own two docks and would like to keep them.  The product description for the adapter states:
Supports analogue audio output, USB audio, as well as syncing and charging.
One of the docks takes the line-out audio and amplifies it; the other receives the digital audio and processes it in its own DAC.  Can someone confirm for me that these two functions would be covered by the adapter?
Cheers.

Answer 1

@Peter Gillespie: I know you're not going to want to accept this, but your reply was pretty condescending.  Why am I telling you this?  Because such attitudes are rife amongst users on forums, including this one, and encountering them is unpleasant.  I may only be a level 3 but it's mostly as a result of having better things to do.  Here's what you got wrong:
The adapter purely continues the function that already exists  instead of sitting a device on the 30 pin that is part of the dock
the adapter allows a device with a lightning socket to sit there instead and still work as if a 30 pin device is in situ
Not true.  Apple themselves admit this in the product description, which continues after the section I quoted to indicate that video output is not supported.  I merely omitted that portion as it wasn't relevant.
You are attempting to make a simple item complex ,unneccessary
Actually, Apple have made the situation complex.  Did you know that the adapter contains a DAC?  That's why it's so expensive.  It exists because without it certain audio functions, such as the Analogue Audio Output I mention, wouldn't be available.
So, Lightning to 30-pin connector adapters are both complex and functionally incomplete.  I hope you can admit that you were wrong on both of your main assertions.  I'm not sure why you spoke about third-party connectors, so I'll ignore the content of that aspect of your post.
@Phil0124: None of my above reproach applies to you.  Thank you for being civil and informative.  I wasn't referring to the headphone socket, but the line-out that is available through the 30-pin connector and which supplies the audio to connected docks.  I was able to confirm officially that the audio line-out portion will function through the adapter, and later also ascertained that the digital output should also be fine (though this was based on anecdotal evidence concerning a 5S, but the similarities between that and the 5 seem sufficient for me).
Best of the season to you both!