2. amps-preamps
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Oppo 105 and Power Amplifier Input Sensitivity

Novice here and needing some advice! Yesterday, I picked up an Oppo 105 to use as my pre/pro for a dedicated 2-channel listening setup. Until I get a set of XLRs, I am using the unbalanced RCAs. I was reading that the output on the oppo is 2.1V unbalanced and 4.2V balanced. I am running the Oppo straight to my Krell S-275 which has an input sensitivity selectable, 2.4 V or 4.8 V - stereo. Using the analog volume control, could I experience clipping that could blow tweeters or my amp? I have read about the 15x rule of thumb on input impedance, but what about the input sensitivity? The Krell is powering B&W Nautilus 804S's. I just want to be sure I don't have to worry about watching the volume when I'm tying one on! ;) Again, sorry for the noob questions. I'm usually a safety third type of guy, but not when it comes to my precious equipment, Ha! 
bconman

Showing 1 response by oldears

oldears
386 posts
 
@atmasphere is correct if the output impedance of the Oppo 105 is greater than 2000 ohms, but it is not specified by them in the manual, and it is quite routine to specify 47 Kohms as a suggested input impedance.
It will cost you nothing to try it with the Krell input set to 4.8V. If you don't get enough volume, you can reset to 2.4V. If you are bass shy, then the output impedance of the Oppo is too high for the Krell, confirming the point by atmasphere. (Be sure to use balanced cables.) BTW, I tried the variable volume on my Oppo, but preferred the sound with a quality preamp.
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