Exchange Krell KAV-250a for a Pass Labs X-350?

Dale, you mention "sterile": to me this sounds like you're questioning the KAVs tonal balance & musicality in yr system. IMO, try the X-350 on this system; listen to light jazz & classical, and check out the X's tonal balance vs. the KAV. You want to be drawn into the music -- i.e. does the Pass render subtle musical details more realistically to your ears? Do the little sounds "make sense", are they indispensable to the musical piece -- or could you have dispensed with them? If they do and are, and didn't and were'nt before, keep the Pass!

Three people I know (who found the KAVs a tad "dry" to their taste) ultimately chose Pass, YBA, Atma-sphere. Pls note, however: COMPLETELY different systems!

Cheers!

Danielk141 You are starting to get into realms that I don't deal with but here but here is the statement for the S-100 manual.
From input to output, the S100's circuits are engineered for very-low-distortion Class-A operation, with a vanishingly low output impedance (long an NAD hallmark) that reduces the sonic impact of cable impedance to near insignificance. And it provides a choice of primary outputs: conventional, unbalanced RCA jacks, and fully balanced XLR jacks. Unlike those in many consumer products, the latter are true "pro-audio" outputs capable of delivering up to 20 volts to 600-ohm loads while significantly reducing susceptibility to external hum and noise.
Maybe you can interpret that. I listened extensively to the Adcom GTP-750 since I owned Adcom equipment before this system. I felt that the NAD was just much more smooth and balanced to my ear. I also discovered during testing different gear that I like the balanced connections between the preamp and amplifier but the single ended connectors between the CD player and the preamp just sounded better.
So what I am getting from most is that there may be a difference in amplifiers but the real difference is in the preamp in my system. I have been listening to a Sim Audio Moon P-5 and was thinking about taking it home soon but I have not heard that much from it that would make me think that I am lacking at home.
GregM, when I am speaking of sterile due to a lack of tonal balalnce, I am repeating what I am hearing from some. I am not stating that I hear that. But I am wondering if I am missing something since I don't know any better. You don't know what you are missing until hear it in something or some where else. I tend to like my listening a but more analytical (favor SS ) than smoothed out (tubular) so I will favor towards something that seems to sound more accurate than something that may sound more musical but lacking detail. So I have to like the sound. My mileage does vary obviously. Dale

Most pre amps with a balanced input and output will have impedance specs simular to the ones mentioned. In a balanced output stage the designer will put protection resistors on the outputs and the value doubles because now ther is two of them in a balanced configuration.

The input and outputs being balanced will quite often double the impedance specs but that does not mean that the input stage did not convert the signal to single ended. The signal then gets processed just like any other pre amp and then gets converted back to differental in the output stage. A fully balanced design has a four gang volume control vs a dual unit for a single ended design. There must be twice the gain stages in the fully balanced design. I hope this clears up some confusion. Chris

Dale,

Ok, you got me there.... I didn't realize the Silverline was a different product line. I've owned other NAD products in the past (cd player, amp, receiver) and found them to be good values, but not "high-end". now I know something new.

Thanks Sqjudge, I am getting some great lessons in balanced circuitry. I just knew how good this preamp was at sonic reproduction so I had to inquire. I did not understand the explanation Of Danelk141 so I had to start investigating. You hit it right on the head of the information that I was reading. The deal of adding four more gangs to the volume control was the reason that NAD stated for not adding balanced inputs to this preamp. Only outputs. Still, I guess that specs don't mean anything unless you can interpret them and understand their value. This thread has been very educational for me. But I am afraid that I have asked an impossible question that can only be answered by experience in listening with the desired upgrade in my own set up. Dale