warmer and better bass sounding tube,please

I noticed at the UpscaleAudio site the list some of the Ah upgrades and they mentioned that the I/U opamps are in sockets that will make them as easy to change as the tubes. The opamps in the player are BB opa604's which can definately be improved upon here is a link to the LCAudio page at DIYCable.com for the AD 825 modules you should contact them to see if they have a replacement option. I replaced four opamps in my Sony DVP 9000es and it made a big difference

http://www.diycable.com/LC_audio_ad825.htm

Have Fun

The Mullard E88CC is the tube for a warm and detailed sound.

I think way many other things contribute to bass than the tubes in one's pre.