Originally Posted by
YeuEmMaiMai 
OK here goes...... I am going to have to seriously question Yamaha here.
I just replaced a HTR-5635 with a RX-V667 and I am having doubts to the new receivers power claims that are nearly
double what the old one is
HTR 5635 weighs in at 21.3lbs and produces (per manual page 57)
* Minimum RMS Output Power for Main, Center, Rear
20Hz to 20kHz, 0.06% THD, 8 Ohm 75W
1kHZ, 0.09%THD, 8 Ohm 85W
/scrolls down to
General*
*Power consumption
[USA model].......................210W
[Canada model]...................210W/260VA
so the HTR model by marketing claims can effectively put out 75w*5 or 375W
lets move on to the RX-V667
RX-V667 Manual (page 117)
*Audio Section
* Minimum RMS Output Power for Front, Center Surround
(20-20kHz, 0.08% THD, 8 Ohm)
FRONT L/R......................................90W + 90W
CENTER..........................................90W
SOURROUND L/R.............................90W + 90W
SOURROUND BACK..........................90W + 90W
/scrolls down to
General section (page 118)
*Power consumption
[USA and Canada Models.................400W/500VA
weight 23.1 lbs
Now something just does NOT add up here and If I had to take an educated guess I would conclude that the increase in heft would be able to account for the slight output increase for 2 channel operation (the additional 15WPC).
Having had the cover off of the RX-V667 to replace the face plate I could see that the transformer did not appear to be significatly larger than the one in the HTR-5635, matter of fact they are very close in size. Also the amp sections appear to be very similar in layout with the RX-V having 4 more power transistors than the HTR-5635 (you know those things attached to the wavy sheet metal used as a heat sink)
so, Yamaha, what gives? did you change how you measure stuff or were you really conservative with the receivers in the old days?