CD player suggestions under $700

mahler123, you are correct that part of my interest in a new CD player is seeing what the new onboard DAC can do. I am currently running both my CD player and Node 2i through the DAC in my PS Audio Gain Cell Preamp that to my ears sounds better than the DAC's in the two devises. My original interest in the Music Hall C-DAC 15.3 was that it has a Burr- Brown DAC for the CD player and a second Wolfson DAC for digital inputs that I could try with the Node 2i. With that I could compare the DAC's in the Music Hall to the DAC in the PS Audio to see what I prefer. 
The suggestion from johnss about a new standalone DAC with a less expensive transport would take me down a similar route. 
I'm not sure what is causing the hum in the Nakamichi CD player but I've tried it with both the analog and digital outputs and with a few different cables and also on a different amplifier and the hum is unfortunately still there. It's been a great CD transport.

Likely needs recapped - power supply. Take it to a shop and see what it would cost as it will be a simple affair, mostly will be labor. CDP with a really good DAC with input for other sources is the Cambridge 851C. Great player and will punch way higher with a good power cord and change out both fuses. The DAC in the Cambridge will destroy the one in any Bluesound player... I own both as well.

adg101.. Thanks for the diagnosis on the Nakamichi CDP. I'll have to check into repair shops. 
That Cambridge 851C looks like a great CDP and with all of the additional digital inputs and balanced inputs and outputs also. Fully loaded.
Must be built like a tank at 22 lbs. Thank you.