OH!! that bieng said this was in response of your 500$ range.This website will be a great place to start and you dont deal with some company over seas they are located in New Jersey and ive used them several times and highly recommend. pacificvalve.com
HEY CHECK OUT THIS SITE pacificvalve.com They have a huge selection of affordable and very decent equipment. I recomend since you have Krell amp and some ML,s you might have some upper midrange grunge or bite (brightness).Not your fault just happens so I recommend some thing a little warm and that may clear up any fatigueing grunge. The Musiland MD-10 DAC has the ability to change its sample rate and thus you can change the sound from warm to all out bright which really helps when you get your next DAC by knowing if you want 192 or 96 because of this DAC. Also it is HARD to beat for the money (375 new).Also audio-gd has the ability to change its sound from warm to neutral to bright so you can adjust to your prefrence. I really hope this helps and post some pics I would like to see what Im helping with! Have a good one! Jay.
Have you given any thought to THETA DIGITAL ? I have owned it for years, different versions of dacs and transports. Stuff sounds killer and Theta is known for having lotsa "slam" and low end detail. I have a Theta DSpro Gen 5a that is 15 years old, been modified twice by the folks at Theta. You could snap one up right here on Audiogon and for cheap! Back in the day, these dacs sold new for 5600.00 bucks and were well worth the money. Of course you could always throw more goodies into it by adding upgrades and new feature mods and such. I got my Theta dac right here on Audiogon, mint condition, for 3000.00....15 years ago. I still see them on this website for as low as 1000.00 bucks. Highend performance at realistic prices.
Well, a good place to start is, how much are you willing to spend? Lots of options out there, but you need a price point. Also, are you set on buying new or will you consider buying used? You'll definitely get much more bang for your buck buying used from a reputable AudiogoN member than you will buying used from a slickster dealer.