Hi I am using SONY NW-A105 walkman as my source to play FLAC & stream apple music to my AV receiver...I was going through specs and found that the walkman output power from its 3.5mm jack is 35+35 mW..i.e total of 70mW Whereas the input sensitivity of AVR is 200mV and I have a separate power amp placed in another room which has input sensitivity of 1 volt...My question is am I giving less signal to my AVR?? Also couldnt spot the difference between mW vs mV...Plz help
Hi manish
If the input sensitivity of your AVR is 200 mV. It means a signal of 200 mV when fed to the AVR, will be amplified to result in the AVR's maximum power output. So ideally, the input signal should always be below 200 mV to avoid clipping or damage. Because an amplifier's amplification factor or gain is fixed at anywhere between 27x to 40x of the input signal. So, only the input signal can be varied to be below 200 mV at all times.
This is what preamps do, they take the 2V line level signal, and attenuate it to below 200 mV before being fed into amplification circuit. And if the signal is very low, they can add gain to boost this signal, but at most times they are only attenuating.
However, in your case, since the output from your walkman is 35 mW. This cannot be directly converted to mV without knowing other factors of the circuit, but it is safe to assume that it will never exceed 35 mV at best. This is at 1/5th of your input sensitivity, and even with the volume of the AVR turned up to max, the amp will not reach clipping levels ( Of course Iam assuming the AVR will not add any gain at its preamp section, but I could be wrong ). So, it is safe enough and will not lead to any damage if that is your worry.
So, best to use the walkman at max volume and adjust the volume on your AVR as needed.
Edit : Sorry I didnt check any of the specs you posted as I have very low bandwidth on my net. So Iam only going as per what you have mentioned in your post
Edit 2 : Okay, I managed to check out the specs page. And it is best to plug in the walkman into the tape or line level inputs, as the 35mV is too high for the MM inputs, and too low for the direct power inputs. However, without knowing the gain stage of the preamp section it is impossible to be sure. So best to first try into tape input with walkman volume at max ( and AVR volume at min and gradually turn it up ), and then try the direct power amp inputs with the walkman at min volume and then turn it up gradually. All the best
