Unregistered said:
1. When I crank up the volume on my 601, to about 85 (on the absolute scale), the receiver shuts down , going into protect mode. Does this indicate a problem, or am I just asking too much of the amp? It is connected to 8 ohm speakers.
It's possible that your 8ohm speakers actually dip well below 4 ohms and thus present a load that is too much for the amp. Could also be that you have a short somewhere - make sure that no speaker wires touch each other. Normally, the 601 will play fine at very loud levels without trouble. Could also happen when playing very dynamic material with huge transients (eg Classical). Any of the above count as pushing the amp too hard; I doubt the amp itself is defective.
Unregistered said:
2. What is the difference between the "relative and absolute" volume scales?
The absolute scale goes from 0 to some number (79 on my 502, I think 100 on the 601). The relative scale goes from -infinity to +10, with "0" being the designated "reference" setting (equivalent to 82 on the absolute scale, per Onkyo manual). For the relative scale, everything is relative to the reference setting. Thus, if you calibrate so that 0 on the volume scale results in 85dB at the listening position, then a volume setting of -10 represents 10dB below reference.
Unregistered said:
3. What is "reference level" - i.e. the "0" point of the relative volume scale?
The reference level is simply the level from which everything else is relative. To match Dolby reference standards one should calibrate so that 0 on the volume scale (or 82 on the absolute scale) yields 85dB SPL at the listening position (or any other value you choose - after all it is your idea of reference that matters). Search in the Beginners section for the topic - I discussed this at length
