My question concerns the output from the DVD player, I am concerned that since the system is 20 years old that maybe the CD inputs on the pre-amp are not designed for the output levels for todays CD/DVD players. Does anybody have any thoughts, ideas, or recommendations? The amp get's warm, but does not get hot by any means.
I have the same P-304 / M-504 set up since 1988 at which time I paid 649 for the amp and 369 for the pre amp. I purchased the EQ-35 and some other Onkyo components at the same time. Still use the tuner and the EQ. Great system with little issues over 26 years.
I thought you might have used the phono input instead of the CD input; therefore, making the phono preamp for moving magnet cartridges come into play - selector button on front of pre amp MM/MC. Not likely though as you would obviously be using the CD switch to control the DVD player. The one thought that might be helpful - does your DVD player have an output adjustment knob on the back permitting you to adjust the output to match other components? I hear no difference in volume when switching from stereo to mono on any component. Not sure why your's increases volume?
The only change I would have liked are the speaker connection posts on the amp. They are not as functional as should be.