Two tube amps for your consideration please

The Jolida integrated amps are unique in that the volume control on their integrated amps are passive. You can easily use it as a power amp, feeding it from the preamp output of your Denon pre/pro. Just by turning the volume control all the way clockwise will remove this pot from the amplifier circuit. Hope this helps you.

As far as your question of the 502 vs. 302:
The 302 uses EL34 tubes and has the gorgeous midrange magic these tubes are known for.
The 502 uses 6550 which is more dynamic w/ a bit tighter control, but you will loose the magical lushness.
I had the 302 in a 2 channel HT system, from Jolida's owner, Mike's recommendation. There was a 3D human quality to music and movies that will simply stunning. As far as HT as you will use it dialogue in movies was absolutely inteligable at any volume level and music in movies was like being at a concert., and sound effect surounded you w/o 5.1. It was amazing!

Old texas dog,

I commented earlier on your request for Jolida 502/302 comparison. I see you are taking requests on other brands. One of the best deals out there is from a "Made in the USA" company. Cary Audio Design from NC has a budget line designed and made in the good ol' USA. Audio Electronics is made in the same facility w/ much of the same design and parts as their high end Cary line.

I have the Super Amp Mk II and it is a stunning performer and should be on your short list for consideration. Excellent build, superb customer service, and that Cary sound. I've had 3 of their products and the new Superamp is amazing. It comes stock w/ EL34 but you can roll KT66, KT77, KT88, KT90, 6550 and others w/o changing any bias resistors. They will ship it direct from their factory to your door w/o a middle man too. Yes they will be glad to take your phone calls too. Now that is service.

http://www.audioelectronicsupply.com/cgi-bin/audioelectronicsupply.com/view_services.cgi?request=detail&dept_id=2&aisle_id=21∏_num=superamp_mk2

http://www.stereomojo.com/AES%20Super%20Amp%20and%20AE-3%20preamplifier%20review/AESSuperAmpMk2andAESAE3Preampreview.htm