Integrated Amp to bypass HT receiver?

Looking for a good integrated amp for music listening. At the time I own a Harman Kardon AVR520 receiver which works very well for HT and it is not that bad for music but I would like it to be better. I will be driving a pair of the new Silver 8 series Monitor Audio speakers. These speakers sound very good at the time but I think they can be optimized with a good tube or SS/hybrid integrated amp. I would like the amp to have a bypass loop so I can use my HK for home theater and the integrated for music. Not sure if this makes much sense. I am not interested in opinions about interconects so please limit the discussion to amps or other similar products. I would like to keep the price under 1500, preferably under 1K and used is fine. Any suggestions on what I should look for would be greatly appreciated.