2. amps-preamps
  3. 156912-146134

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 4 responses by bconman

bconman OP
5 posts
 
That's part of what I'm trying to figure out as well...would I be better off with a pre-amp with a lower output sensitivity? Also, the Oppo recommends 47K Ohms on the input impedance. My Krell only has 20K Ohms... what am I losing in this combination? 
bconman OP
5 posts
 
Well, shoot. I thought I was being sly and budget conscious to use the Oppo as a pre/pro for the Sabre DAC... If I get a true preamp, that renders the oppo DAC useless right?  Thank you, btw, for helping me understand how this works!
bconman OP
5 posts
 
So, the input sensitivity only changes based on the cables you are running. XLR vs RCA. Still only using RCAs (2.4v) while I try to find a decent set of used XLRs, but when listening I immediately thought that it lacked the bass it had before the Oppo... I thought it was the crossover on the Oppo (not running a sub right now) so I lowered it down from 80hz to 50hz but still thought it was lacking something. From the metrics I gave in my OP, how did y'all know it was going to be bass shy? Still trying to understand the relationship of the mathematics. 

GAIN Selectable, 25.8 or 19.8 dB - stereo Selectable, 31.8 or 25.8 dB - mono INPUT SENSITIVITY Selectable, 2.4 V or 4.8 V - stereo Selectable, 1.7 V or 3.4 V - mono INPUT IMPEDANCE 20 kOhms single-ended 20 kOhms balanced
bconman OP
5 posts
 
The Krell input is 2.4V unbalanced and 4.8V balanced. The Oppo is 2.1V and 4.2V respectively. I was just reading about spikes that could cause clipping at high volumes. People were talking about using attenuators to reduce the Oppo's output Vrms...??
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