Considering switching from Audio Research to PrimaLuna, troube with VS115 amp

Thanks Kevin and enjoy your trip.  I appreciate your throwing this together and also for changing up some of your approach at some of the suggestions.  I think you really got a more interesting set of results than you might have otherwise (great call on the 3rd amp). 

And for those who participated, thanks very much for your reports on your impressions...very interesting.

At the risk of sounding like a total KT150 fanboy (I may be!), I was interested to see how that variable might shake things out.  I truly think it's a special combo with the PL amps AND the ARC amps...the PL HP in my case really went to another level.

However, I realize it's been a while since I've had the PL-provided EL34s in the amp, so I'm going to do my own comparison and go back to the EL34s that shipped with my HP for a few days and see how they sound again.

@parsons
here are Kevins comments on EL34 vs. kt150 from Page 4 of this thread. "I use an HP at home with KT150's and it's amazing.  But it's not night and day from a stock one with EL34's.  It's a small nudge."

So why is it that at the very same time, PL makes it sound as though it's auto-biasing and protection circuits are revolutionary? Even evolutionary?

The nexus of PrimaLuna is a man not happy with what's being made, who is very good at gathering engineering talent and looking at problems.  Herman van den Dungen is that man.  He also is the man created Kiseki, and created the Ah! Tjoeb CD player both of which have near cult status.  

My input come from being the complaint department  for most every brand of tube audio made.  When a poorly designed tube preamp with 27dB of gain goes through tubes, it's the tube dealer that has to explain it more than the company that made preamp.    And we've re-tubed over 70,000 components since Upscale Audio opened over 20 years ago.  Hence my involvement.  Whether it's evolutionary or revolutionary..I can't say.  I CAN say it's careful consideration of what IS possible.  

You are buying a fabulous statement product that will serve you well.  Both the preamp and amp are beauties.  I don't know if you said what you plan to do about speakers?  

pokey77--agreed, that comment and the Saturday event results prompted me to put the EL34s I had neatly foam wrapped in the cabinet back into my PL HP last night for a couple more hours of listening, and I have them playing right now again as I verbosely type.

Quite lovely, actually.  I bought my PL HP used and don't really know if it was fully broken in when I was first listening to it, if my system synergy has changed, etc., I don't know...perhaps it sounded this good with EL34s from the beginning.  My system hasn't changed that drastically in the 2 or so years, but I concur that the difference in sound is not that great (probably not as great as I imagined).  The EL34s are even better than I remembered, and it's not that they weren't great when I got it, I just had the itch to try KT88s, KT120s, and KT150s because the amp let me, and they all sounded good to great to greater.  The move up the KT "line" to 150s was fun (expensive, in retrospect) and each move removed a bit of things I didn't love with each move, and gave me more of the things I did love.

I think the EL34s simply feel a little softer in the lowest register, but not weak, and there is maybe the slightest loss of ultimate sparkle in cymbals, etc., with maybe the slightest shrinkage in soundstage.  But overall they are a really lovely tube, with more drive and immediacy than I had remembered.  And the tones and texture are absolutely gorgeous.  I can see why people love this tube and see why it still ships in a number of the PL products--it's really a great sound.

I'm going to keep them in for a week or so before I go back to the 150s and see if my opinion changes again, but I agree that the changes are more subtle than I had originally remembered.

It just struck me that in some part of that driver tube upgrade journey I also swapped out the 12AU7s for something that was reported to be a better-sounding-than-shipped tube set (and were)--but that sends me back to this unfounded conclusion...as Kevin astutely called out earlier, the sound can change a lot with the two amplification pre-tubes.  Perhaps that contributed as much to my improvements at the time as the upgrade to KT150s, and now going back to the EL34s that difference alone isn't that big?

I do maintain that the pre-section of the integrated, while great, is actually holding back the last ounces of amazingness that this amp alone is capable of.  Put a really, really, really nice and transparent pre-amp in front of it through the HT bypass inputs and you will get more of what it's capable of.  In my experience...YMMV.  I make that point merely to suggest more experimentation in your own system.

The headphone amp is rarely mentioned, and that is a phenomenal addition to this amazing amp that probably doesn't get enough praise by itself.

fsonicsmith, I agree that it would be very interesting to see the PL HP (or non-HP) against some of ARC's references and other brands', including the separates stacks obviously (in the reference lines).

I don't have an easy way to get my hands on really expensive amps other than buying them, so while I own a lot of very good to great amps, I'm in the territory where moving up in quality is a used car like investment...not an "experiment" I can make any longer.  My local ARC dealer doesn't seem to have a way to get their reference amps and pres in for demo, oddly, even though I've expressed an interest and means to buy them if they are that much better.