Power Amp Question

I do not post much, but - the NAD should be powerful enough to give you hearing damage in under 10 minutes with that setup. Before you go and spend a bunch of money, in my opinion it would be a good idea to verify all your components are working according to specification.

I took a look at your picture of your listening room - it is not very large, and the NAD with those speakers at 92db 1w/1m, according to the specs should be able to drive  them to 110db at 64 watts at 1m, and depending on where you are sitting (you will lose 6db at double the distance); so - 104db at 2m. 104-110 db is quite loud - as in, rock concert - hearing damage loud (supposedly hearing loss will start in about 7 minutes at those levels). You need 128 watts to get to 107-113+ db (Double the Power Rule-When you double the power, there will be a 3db gain in SPL)  and you would need a 256 watt amp to get to 110-116db.

The NAD has 220watts of dynamic power at 4 ohms, so I am surprised it is not powerful enough, especially in that small room.

This makes me wonder if your input to the NAD is high enough to allow you to get to full output (the NAD specs says its sensitivity is 500mv). Is the NAD loud enough when using the CD player? If it is, and your analog setup is not loud enough, then something is not right with your analog setup. The AT-OC9XL is a 0.4mv output, so into the Aria at 63db gain at the MC inputs, should get you to 400-500mv into the NAD, which should be enough to get the NAD to full output.

I suggest you download the Decibel X app for your phone (or a similar decibel meter for your phone) and find out how loud your system is now when using the CD player in your room. If it is not at 104db or better when the NAD is maxed out, something is not right. 

Hi George -

A couple of things - 

1. I think @sgreg1 is absolutely correct - not all amps are created equal. If you are turning up the knob to super high sound levels to get the full sound stage, then I think something is not working well for that 'first watt' as sgreg1 put it. A "better" amp, or better synergy between components will give you that full sound stage at lower levels.

2. The position of the volume control with an analog potentiometer like the NAD has, is an attenuator for the source (eg: the CD player or the turntable) - the preamp itself may have gain too, but I have found that at the 12 to 1 o'clock position is usually where unity gain is (meaning no gain, no reduction to the input signal); so, if the input signal is below the amplifier sensitivity level, you will not get full amp output at that point. Then there are digital volume controls which have no 12  o'clock necessarily - they just spin a number representing the attenuation - sometimes in db.

I think this video does a pretty good job of explaining the "volume control" -