I have to disagree w Marakanetz. Check out member Dougdeacon's system. He is driving 803Ds w a 60 wpc tube amp (2 el-34s per channel). The 804Ds are rated at the same 90dB efficiency as your 804Ds, in a smallish living room, maybe 14 x 16 or so. I've heard his system several times and I can tell you that the amp is more than capable of driving those speakers very, very well. I have the same amp and it does quite well w 89 db Merlins in a 14 x 23' room. Whether your amp and upstream components will deliver the undistorted signal that the 8XXd's demand is another question. If you have any HF nasties coming thru, they will reveal them ruthlessly. But as far as power goes, that should not be a problem. IMO, YMMV, etc, etc.