<font color='#000000'>I have checked the volume output on my Z9 and it registers + 12.5 db. at full open. My ears start to object to the loudness of a DVD/CD source at -7 db, so if you are considering listening to any source at +6 db you better be prepared to do the following:
(1) Replace the tweeters in your speakers.
(2) Replace the rail fuses in your amps ( a qualified service center repair required).
(3) Start a savings account at a financial institution for hearing aids, cause you are going to need them at a very young age!
Without (I hope) trying to sound like some sort of smart-butt know-it-all, perhaps an explanation of the volume control use is in order, so here it goes:
If you open a water tap (volume control) slowly, the water reservoir and pump (your transformer and storage caps) will continue to supply pure water (sound) to your sink (speakers). The reservoir is being supplied by a steady flowing creek (110 volt power outlet). As the tap is opened more and more, the reservoir and the pump are under stress trying to supply the evercreasing demand for pure water to your sink. So let's crank that tap wide open. The pump quicky drains the resevoir of pure water and begins to draw muck, sand and other polluted materials and sends this crap out the tap to your sink, eventually plugging it ( i.e. clipping the amps resulting in blown fuses and fried voice coils in the tweeters). A volume control is a very crucial part of a receiver, and must be used with care!!
Even a tweeter as small as 3/4" will take an enormous amount of short-burst wattage (1000 watts and up), as long as the signal is clean and free of distortion. A tweeter goes into heart arrest trying to play a clipped square wave (distortion) it cannot follow and dies. Likewise, your power supply will overheat and put your receiver into a protection mode ( shutdown and/or fuse blowing). This partially explains why the Yamaha Z9 and the Denon AVR5803 are pushing 70lbs. in weight, while the one at Costco claiming 200 watts a channel can be lifted with one hand. Large storage capacity ( transformers and caps) are expensive and very heavy!! It is this storage capacity that gives you solid, clean sound while the lightweight receiver chokes on it's own vomit. Storage supplies in receivers are taxed to the limits by fast transients and by sudden shifts in dynamic range - the rim-shot on a drum, a soaring voice, a roaring piano, a rocket launch ( a good example of the last one mentioned is from the Imax LD/DVD "The Dream is Alive"-the crackling of the hot exhaust gases colliding with the air are tweeter friers, and the powerful low bass at the same time is an storage capacity drainer!).
I remember reading an article years ago where a prominent amp designer was trying to develop a power supply that would not clip. And what was he using as a sound source to conduct his research and that was constantly fustrating him by putting his amp into overload.?? Why, a live mike of someone cutting paper with scissors!!!
Maybe you have a genuine complaint about the volume on your 2400 that no amount of fiddling will address. I suggest you take it back to the dealer and have it tested by their repair department that will check the volume output to see if it specs out.
Al</font>
