Best 5 channel amp under 4k

Without a doubt, I think the best 5 channel amp in your price range is the Krell KAV 1500. 300 pristine watts into each of the 5 channels. This is really a very impressive amplifier. Retail was $8500, but can be found on audiogon in excellent condition for around $4500. I don't think anything can come close to it's performance and sound in that price range.

Bryston 9BST is without a doubt the best 5 channel amp out ther under $5000.00. It can be purchased second hand for between 2500-2800 dollars. Bryston has 20 year transferrable warranty as well.

You can usually find a pristine, pre-owned EAD PowerMaster 2000 for well within your price range. You won't find many 2-CHANNEL amps that will sound better than the PM2000 and the PM2000 has the 5 channels you are looking for. The others mentioned a great too though.

Used/Demo BAT 6200 5ch. amp could be found for that money.

POWERMASTER 2000