Finally upgrading my amp

I do believe an integrated amplifier is the way to go at your budget.

I assume you are using the phonostage within the Denon receiver and the CD player as a stand alone.  If this is true you will need a new phonostage as well. Also, if the CD player is working well you might want to consider the purchase of a new DAC and use the CD player as a transport via the coax digital output on the player.  

One consideration is that Integrated amplifiers can be purchased as line level (amplification only) or with either an internal DAC and phonostage, or with both.

Another consideration is how much power you feel you need. Does the 50wpc Denon suffice? 

Your thoughts on the above would help us help you.

Great suggestions here: Rogue, Peachtree, Hegel.

Shopping at The Music Room will net you a great, checked out piece. Here's a search result with a bunch of good options selected.

Here's the  CERTIFIED PRE-OWNED list I chose from what is currently available:

• Linear Tube Audio MicroZOTL MZ3 Tube Headphone Amplifier; Integrated; LPS+ $2,549.00 
• Hegel H120 Stereo Integrated Amplifier (1/2) $2,249.00 
• Hegel H120 Stereo Integrated Amplifier (1/3) $2,099.00 
• Hegel H120 Stereo Integrated Amplifier $1,979.01 
• Cary Audio CAD-300 SEI Stereo Tube Integrated Amplifier $3,999.00 
• Jolida Audio DJ1000 RC Stereo Tube Integrated Amplifier $1,175.14 
• Peachtree Carina GaN Stereo Integrated Amplifier; Gloss Mocha; MM Phono (Unused) $2,771.01 
• Peachtree Nova 300 Stereo Integrated Amplifier; MM Phono $1,066.36 
• Cary Audio AiOS Wireless Stereo Integrated Amplifier; Roon Ready; BT $1,425.54 
• Lyngdorf TDAI-2170 Stereo Integrated Amplifier $2,823.50 
• PrimaLuna ProLogue Premium Stereo Tube Integrated Amplifier; (No Remote) $1,551.51 
• PrimaLuna EVO 100 Stereo Tube Integrated Amplifier; EVO100 (No Phono) $1,835.10 

The Rogue Sphinx V3 integrated around $1700 with a good phono stage.

I support all the suggestions so far. Used gear is the way to go unless you have a big wallet or want the security of "New". In addition, the amount of functioning used gear is almost unlimited. If you enjoy the hunt, CL and MPlace in your area is a great place to start. No shipping and prices can be amazingly low and most sellers are not getting enough traffic that they eventually just want it out of the house. Upgrading your current Denon to newer main stream brands like Denon, Yamaha, Marantz, Pioneer etc can be rewarding and may meet your desired enjoyment needs. Then you can continue to swap for better and better gear. Add a Streamer like a $219 "Wiim Pro Plus" so you can evaluate your next upgrades and features that you would like to add to you system. As you can tell I am frugal because I have to be but the system I have put together on a frugal budget that provides me with enjoyment that I believe is an audiophile experience. Good luck hunting and have fun!!!!