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

Would I gain anything by exchanging my Krell KAV-250a for a Pass Labs X350? I am not dissatisfied with the Krell. It seems to be a pretty good match for my Dynaudio 1.3 Se�s. But yet I do not know what something else would sound like. I do know that these speakers like a chunck of power and they tend to be easy to get good sound out of. If the Pass amps will not be a vast improvement, what would be a good choice? I generally listen to jazz and a bit of rock and classical so my demands are not huge. I am using a NAD Silverline S-100 preamp and I have a Velodyne HGS-15 sub for when I want to rock but for the lighter jazz and classical it is not necessary. The only other upgrade that I am considering is moving to the Harmonic Technology Magic interconnect and speaker cables. I would appreciate some education on what would be the best amp for this set up. Dale
Dale: r you sure the Krell is the culprit (if culprit there is)? Can you try another pre -- just for the experience (just a suggestion, pls don't go into sudden pre upgrade mode...:-)

I personally like the Pass X better than the Krell KAVs -- but so what? I listen to classical, blues & jazz and have not heard your amp-speaker combo, to boot! Also, I'm sure the NAD's a great machine, but how's the chemistry w/ your Krell?

What's your source, BTW?
I agree with Gregm: the Pass is probably the better sounding amp, and IMO, if its available to you for the ease of a swap, I'd do it. However, I'd guess you'll notice a bigger difference by upgrading your preamp. NAD is ok but not in the same league with Pass/Krell and Dynaudio.
Yes, that is the pendulum Gregm. I do not know yet. But the general consensus is that the Krell may be a bit sterile or have a sound. I am just looking for my next upgrade path if I need one. I have tried a number of preamps, tubes and SS, and I have landed with the NAD Silverline but I also restrict my self to a budget. So I am looking for people who might say, Yea, I know quite a few people who have had that problem or this with that and they changed to ?
My sources are the Silverline S-500 CD and a Project Perspective with a Blue Point Special. Dale
Mg123, I do not think that your statement about the NAD Silverline preamp not being in the same level as the Krell, Pass, or Dynaudio is in fact. The S-500 is a different animal than the regular NAD equipment. The Silverline is NAD's bid at the highend. I chose it over the Krell KAV-250p and others. It had a much more balanced sound and it's build qulaity was a notch better. It's Danish heritage was very evident. I don't know why the Silverline suffers from PR problems but it could have something to do with NAD not giving free samples to the American audio media. They make them buy the samples. Go figure. But after going through a few preamps to buy the NAD was the winner in overall sound quality so I was not focusing on it. Dale
Would you borrow the Pass amp from a local dealer? Try a Pass X series pre-amp first. They are truly balanced - like the X 350. I think the KAV-250a is truly balanced?! You might want to try an Adcom GFP750 pre-amp also. It has single ended & truly balanced inputs & outputs, & was designed by Nelson Pass, who founded Pass Labs. I use the GFP750 with my Rowland Model 2 in balanced mode & it works quite well.
I've seen the NAD pre amp at a local dealer, I believe it is "psuedo balanced" which means although it may have "balanced" inputs or outputs, they are coverted inside the pre-amp to single ended anyway. Check the input & output impedance numbers. The Adcom input impedance measures 94k ohms balanced, 47k ohms unbalanced. Output impedance 1200 ohms balanced, 600 ohms unbalanced. When the balanced value is double the unbalanced value, the component is "fully balanced" or "truly balanced".
I also own a Pass Aleph 3 amp, it is single ended only, when I use it I run the variable out from my SONY XA7ES directly into it.
If I were you I'd give the Krell another chance with a better pre-amp.
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!

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

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
It is indead a tough question ....

I have heard several pieces of krell gear and it is always very good, but one of the most musical adutions I have ever had was thru a Pass pre and an X350. It was truly magical. Remember that this was my experience and your mileage may vary. Chris
I have listed to both x-350's and Krell's. I bought an x-150 and an pass labs x-1 pre-amp. I like the match between the x-1 and x150 the best. The preamp makes a larger difference than an amp. I also own Harm Tech cables. Try the Pro Silway II's and 9's before the magic. I could not tell them apart.
I already own the Pro Silways ( balanced from pre to amp and single-ended from CD to pre ) and the Pro-11 and I am very happy with them. But if there is more to be had by a simple cable change then I am willing. I am surprised that you didn't find any increase in detail and delicacy with the Magic. The system that I listened to at a local audio hut displayed a significant difference in the two cables. But I guess that just goes to prove that it is all about synergy. Dale