Warranty question

I am buying a 6 month old used amp unit from an authorized dealer. Warranty on a new product is usually two years. Normally, if buy used (from a consumer), with most companies the warranty becomes void. However, I am being told that since I am buying used directly from an authorized dealer and they are providing a sales slip, I will in fact have warranty on my product. How does this sound? Is it correct? Sound OK since I have sales slip? Just a local dealer work-around of big company rules? Thnx.