Anyone has STR-DE597 receiver (this one is CEL code). I have a few questions: 1. The volume scale on my receiver is from 0 to 74. In which units is this expresed? Decibels or smth? 2. May I keep volume on the receiver on the maximum and for how long (before damaging it from the heat that bulids up)? 3. In specification of the receiver is written: rated power output at stereo mode(8 ohms 1 kHz, THD 0,7%) 100 W + 100W, measured under 230 V AC, 50 Hz. Is this RMS power or what? If not, how much approximately is RMS?
The volume control in this case meanse very little. Other that "0" is no sound and "74" is loud and distorting badly.
You have to use your own judgement on "how long" you can play it at maximum. I would think that the clipping/distortion from that amp would destroy your speakers before the amp fried, but who knows. If it gets tooo hot, it will go into protect mode.
That power specification tells you little. Note that they rate the amp at 1khz, not from 20 to 20,000 hz. 1khz is an easy load and that kind of measure does not tell you what the amp will deliver when it is pushing a 20hz load.(assuming it even goes that low, I seem to recall the 595/597 only went down to 40hz). It takes substantially more power to drive below 1khz than at or above it. I doubt seriously that you will be getting 100watts RMS. Many companies are rating their HT receivers this way now, sadly, even Yamaha is rating their HT receivers (the kind at Best Buy) with this 1khz worthless rating.
Note also, that they also rate it at stereo mode, not all channels driven. You will get appreciably less power when driving all speakers.
Thanks Shan Tao. I am using this receiver with sony tower speakers SS-MF450H, maximum input power 150 W. What is their RMS aproximately? Am I risking to damage my speakers when I keep my receiver at max (74)for a couple of hours? Are mission speakers better than sony?I am thinking to by them.
Why do you always want to turn the volume knob all the way up? Just because we can turn it all the way up doesn't mean we really want to turn it to its max. When the volume control goes pass its halfway, distortion begins to appear more and more. If your receiver puts out too much power for the speakers to handle, you'll likely damage the woofer(s) and if your amp doesn't have enough power for your needs, when you increase the volume beyond its capability, clipping will eventually occur, which will destroy the tweeter(s) on your speakers. As someone in the other thread of yours suggested, increase the volume to the point you start to hear distortion from the speakers then you must turn the volume control back down. It doesn't matter how much power your receiver can provide and how much power your speaker system can handle, you never want to turn the volume control to the max. The receivers, speakers and the type of music you're listening to have their own characteristics so it's hard to tell from 0 to 74, what should be the proper volume setting for your system. For each type of music, you need to do some experiments to find out for yourself. Remember music with lots of bass will require much more power from your amp.