This is a pretty system dependent question. I suppose too many tubes could impart excessive warmth, but I also think it depends on what those tube components are. In my system, I decided against a tube digital front end, since I was already running a tube amp and preamp, made by the same manufacturer, that is known for a fat and warm house sound. I tried a couple tube CDPs and did find that the music was a bit too fat and warm for my tastes. Might the result have been different if my tube amp and/or preamp were from a different manufacturer, possibly, but at the time that is all I had to go on.
If possible you should get the Njoe Tjoeb on a trial basis and check it out for yourself. Upscale Audio offers a trial period with a 10% restocking fee. A small price to pay to guarantee system compatibility. Also, I noticed Upscale has a used Cary 308 (not the 308T which is the tubed version) for $899. Not a bad deal for an excellent CDP. I have also heard good things about the Onix CDP which is in your price range. I believe Underwood Wally sells them and I think he also provides a trial period. The only way to truly find out what is best in your system is to sit and listen.
If possible you should get the Njoe Tjoeb on a trial basis and check it out for yourself. Upscale Audio offers a trial period with a 10% restocking fee. A small price to pay to guarantee system compatibility. Also, I noticed Upscale has a used Cary 308 (not the 308T which is the tubed version) for $899. Not a bad deal for an excellent CDP. I have also heard good things about the Onix CDP which is in your price range. I believe Underwood Wally sells them and I think he also provides a trial period. The only way to truly find out what is best in your system is to sit and listen.