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

It's been fun reading. I am not surprised at the impressions and that is meant only as a complement to PL. While I have difficulty swallowing Herb Reichert's standard deviations away from objectivity, there can be no doubt the PL gear is solid based upon the favorable comments in S'Phile. I believe that Kevin Deal and I have talked past one another on the issue of preamps but such is neither here nor there. Generally speaking, modern ARC gear tends to be fairly "in the middle" between classic tube and ss sound and I understand PL to be a bit more on the tube side of the spectrum. Prolonged time with the gear (months, not minutes) would likely bear that out. It is always possible that the Focals impedance curve lessened the difference. The critical interplay between speaker characteristics and tube amps has been explained by Ralph Karsten of Atma Sphere here; http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php
Don't get me wrong-the friendly comparison seems fine. For perfectly selfish reasons, I would love to read about a similar comparison between ARC's top gear-let's say the Ref 6 and Ref 150se vs the top PL separates. That would tell us whether PL can claim to be giant-killers-even if they simply pull even-or are instead simply great value. One related issue which brings us back to the OP, I think, has been glossed over-ARC gear has typically used resistors as the "fuse" for malfunctioning tubes but is it because ARC is just lazy/non-caring/behind-the-times or do other options ultimately degrade the signal/sound? Read any reference you wish on tube amp design-this one is good; http://ken-gilbert.com/images/pdf/taste_of_tubes.pdf and you will see that there is nothing new under the tube amp sun. 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? 

@tablejockey 
I used the word “unblinded” as in we could see Kevin’s making the cable swap as opposed to the blind switch where we were "blinded". 

@jbhiller 
"It seems like the takeaway is the Primaluna product is a solid bet with tons of value" I'd agree with that statement.

@upscaleaudio 
I've heard the KT150s in a few amps and always liked the way whatever amp was playing them sounded. I actually preferred the KT150s in the ARC VSi75 and felt the overall sound was very close to the EL34-tubed HP. As jbhiller noted above, there is tons of value in the Primaluna gear and when you have two pieces of gear that essentially perform the same, price should win the day.

Kevin, I also appreciate your transparency in talking about how the smaller driver tubes can make a large and significant affect on sound quality. That lets others experiment in a way that is easier on their audio finances.

Also, experimenting with tubes in Primaluna product is much easier since they have an autobias circuit; this adds to the "tons of value" in PL. -Not everyone wants to be biasing tubes.

Hello Kevin,

Thx for hosting the party and I really enjoyed it.  Glad to meet with other folks with the same interests.  Bob, it was a pleasure to meet you as well.  Let's do that again with other gears in the future, I am sure it will be fun!

I am also impressed with the HP integrated amp.  Let's talk some more when you get back from Europe.

Allan

@fsonicsmith 
Quoting you "Generally speaking, modern ARC gear tends to be fairly "in the middle" between classic tube and ss sound and I understand PL to be a bit more on the tube side of the spectrum." If you'll read my comments above, I thought the EL34-tubed DiaLogue Premium HP sounded very similar to the ARC VSi75 with KT150s. The listening didn't really bear out your assumption. But I do agree that listening over a much longer period of time would show more of the minute differences in these fine integrated amps.

Please see Kevin's post several days back on 07-14-2017 2:06pm, where he has provided a link to the Taste of Tubes document you mention. He also mentioned later on that he hoped the readers of this thread had downloaded that document.

Indeed a comparison between top ARC and PL gear would be fun. Kevin never claimed his gear were giant killers and but in fact he did say "I would be ecstatic with any of them, and would prefer them to a stack of reference solid state separates." 

"But I do agree that listening over a much longer period of time would show more of the minute differences in these fine integrated amps."

Hello pokey77-these amps were so close, that to REALLY discern the differences IMHO,I need to hear just 3-5 second "snippets" and IMMEDIATELY have the ability to switch to the other amp. Even though Kevin did a fine job of switching, it's just not fast enough.

My  sonic memory just isn't that good.

On a side note: I'm discovering the PL HP really does need to be opened up to hear what a fine piece of equipment it is. I listened to that SRV cut  at a very high level-3:00 o'clock, and my speakers really came alive. I played "Tin Pan Alley" from the record I purchased in 1984! WOW