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An Interesting Comparison: Krell vs. Van AlstineRecently we gathered at David's house for a second listening session. The first took place at Herman's house where we compared DAC's.
http://www.audiocircle.com/index.php?topic=117771.msg1236340#msg1236340 This second session was a mishmash of equipment swapping with a little scotch to improve our listening skills. Unfortunately David's Krell pre-amp died a few days before the meet but we went ahead as planned. Herman brought a DIY buffered line stage and I brought the Van Alstine Fet Valve Hybrid pre-amp. Sources were all over the place: a Mac mini, an Oppo 105, and a laptop with external HDD all plugged into the PS Audio PerfectWave MK II.
Amplification was by the Krell Full Power Balanced 200, Van Alstine Synergy 450, bass was supplied by a REL Gibraltar G-2.
Speakers were the amazing Magnapan 3.7's. these 6' tall panels can fill a room with excellent sound but they only go down to 40 Hz (maybe) so a fast sub is a must have. The tweeter panels were set up to the outside for a wider, more diffuse sound stage so I didn't get to hear the pin point imaging these speakers are capable of.
David and Herman's music of choice is classical, mine is everything else but classical so it was a broad mix of clashing styles.
The first go round used Herman's buffered line stage, the sound was OK but we had volume issues. Both the Oppo and PS Audio have volume controls but not enough to suit us, I would have liked it to go louder but not to take any more time to trouble shoot we listened to music instead. Nice but no goose bumps.
The second lash up was the AVA pre along with the AVA Fet Valve Hybrid DAC, now we had volume. Our impressions of the PS Audio and AVA DAC's were exactly the same as before. Their sound is so similar that in a sighted (or blind) test it would be impossible to tell them apart. The Perfect Wave's higher price is justified because it has so many cool features, definitely check it out if you want the Swiss Army Knife of DAC's.
We decided to start the amp comparison with the Van Alstine Synergy 450. My gosh, the sound was so close to what we heard with the Krell that we had to try out a lot of different music to find out if there really were any differences. Bass was a wash because the REL did all the low stuff, turn off the REL and the 3.7's didn't go low enough by themselves to notice any difference.
After a mash-up of music ending with the Dire Straits "Love over Gold", David and I agreed that even though everything sounded excellent, what was missing was the sharp attack of a note. A politeness maybe. The leading edge was ever so slightly attenuated; not even noticeable unless you heard the Krell first. Putting the FPB 200 back in confirmed our impression, but to my ears that was all that changed. The mids, highs, and low level information seemed identical to the Krell.
We think the difference in attack is because the Krell, besides weighing 3 times more than the Synergy, runs in Class A. All of the FPB 200's 400 amps/channel (4 ohms) are ready to go instantly. David said the Krell is not kind to poorly recorded music, though never analytical the quickness and clarity can put an edge to the sound which is where the PS Audio PerfectWave filters can make a marginal recording very listenable.
I think the 3.7's like plenty of power to come alive, even though both amps are over 200 watts per channel the Krell has the braun to back it up, it is one big amp. The Van Alstine Fet Valve 600R Hybrid amp would probably be a better match to the 3.7's and give the Krell a run for it's money.
Back home listening to the Synergy 450 through the Salk HT2-TL's leave little to be desired. The RAAL tweeters are just as revealing as the Magnapan's and if there is any leading edge attenuation it doesn't show up here, but I do have a dedicated 20 amp outlet if David wants to do another comparison.

As a side note one big difference between the amps was the heat they produced. Yes, Class A runs hot, but you have no idea how hot until you spend an afternoon with one, especially during a Tucson summer. The huge Krell amp was too hot to touch all afternoon, that sucker is a full on room heater. A+ for sound but definitely a winter amp.
Wayne