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


Hello everyone, I have question that I hope some of you either can answer or have an opinion on. Ever since I was 17, I have always wanted to own Audio Research equipment. I’m 56 now, and finally was able to fulfill my life long dream. My first acquisition was an ARC LS15 pre-amp bought here used in mint condition. I paired it with a Vincent 331MK hybrid amp also bought here used in mint condition. The resulting sound was impressive. After that, I started looking for an ARC amp I could afford. The resulting search found me an ARC VS115 amp also here in used, awesome condition. This is where my problems and my doubts started. Upon hooking up the amp to my system, a tube in the left channel arced and blew a resistor. I had to take the amp to an ARC dealer and he installed a new resistor and suggested I buy all new tubes from ARC for the amp. I did and when I got back home, I again hooked up the amp and immediately upon turning the amp on, I started to hear thumping sounds coming from my left speaker, then, two left channel output tubes started to glow a very bright orange, and then white smoke started to rise from one of the tube sockets. I immediately turned the amp off. I called the dealer and he suggested I mail the unit back to ARC. I did and I am now waiting to see what they say.

During this time, I started to search out other brands and came across one called PrimaLuna. I have watched their videos and seen them compared to ARC equipment. Their build quality seems to be superior to ARC and the reviews are over the top. I am looking at their Dialogue Premium HP amp and their Dialogue Premium pre-amp. For what they cost, considering how they are built and supposedly sound compared to units costing 3 to 4 times their price, they almost seem too good to be true. Anyway, my bubble has been burst, and in simple terms, I am considering jumping ship and going with another company instead of ARC, despite all those years of drooling and waiting.

My main question is this, is there anyone out there that either owns PrimaLuna or has had experience with the equipment and can give me their opinion on owning and using it. Then, my second question is how does PrimaLuna really compare to other high end equipment such as ARC. Kevin Deal in his videos on PrimaLuna makes a very compelling case for the equipment. In one video, he compares an ARC LS17SE to the PrimaLuna pre-amp.

My last question is in regards to my ARC VS115 amp problems. Anyone have an opinion on what is going on with my amp or a VS115 in general. For those of you who want to know what else is in my system, I am using KEF 104ab speakers, a Cambridge Azur 752BD Blu-ray player as my CD player, Morrow Audio Cables and I am considering getting the Sony HAP-Z1ES music player for my digital files.

I greatly appreciate all who take the time to comment and give their opinions. I will be glad to answer any questions you may ask or provide additional. Thanks for your help. Steve.


128x128skyhawk51

Kevin you keep bringing up the Cary AE-3DJH. Since when was it ever a standard-bearer?


That review was the wrong preamp. The AE-3MKII was OK, but not nearly as good as the AE-3 DJH, which stood for Dennis J Had because he felt it was his best design. And at $1500. I never said it was a standard bearer. It’s an example of how simple it is to make a decent tube preamp cheap. Some would put it in a big empty box with a nice faceplate and charge $5k for it.

This comment about an amp “regulating AC to DC” is like…I don’t agree, respectfully. Tube amps also handle small signals. But that’s when it gets complex. Because of the power needs of the tubes, you need a massive power transformer unlike a preamp, then you need good regulation, which is easier on a preamp, then the driver section to drive the grids of the power tubes, then the biggest key: Output transformers. Expensive, and you need two of them. No matter what else you do, if you don’t have great output transformers, it all means nothing. Preamps don’t use them except for a small number of transformer coupled preamps like BAT’s top models.


PL has taken traditional but dated basic circuit designs, added some user-friendly features, built them to tank-like standards, and at great prices

This is true, but it’s about SOUND not just being user-friendly.

Adaptive AutoBias is ADAPTIVE. There have been auto bias circuits before. Even from Golden Tube Audio. AAB is about sound quality when tubes have many hours on them, or when they are pushed to their limit and experience pinch-off. It also allows the amp to run in Triode or Ultra-linear at the push of a button on the remote. And it’s how you can flip a switch to fine-tune performance between smaller dissipation tubes like EL34/KT66 and larger dissipation tubes like KT88/KT120/KT150. And finally, it protects the amp instantly in the event of a tube short, which would have helped the guy that started this thread, and would have told him which tube was the culprit and eliminate drama.

It was engineered by the Chief Designer for Goldmund in Switzerland, who was credited with penning some of their most iconic products.

A REAL engineer. Who also designed the output transformers and created other PrimaLuna designs you won’t find elsewhere like the AC Offset Killer to help make the power transformer dead quiet, the circuit on each input that provides a solid input impedance to source components, a proprietary cross coupled feedback on the power amps to add control without the negative feedback nasties, power transformer and output transformer protection in case of customer mistakes, and also created the Tjoebclock vacuum tube to address jitter in PrimaLuna CD players and the upcoming DAC. All performance. All exclusive to PrimaLuna.

As to “dated basic circuit designs”, there are no new designs. In preamps or amps. Most every push-pull amp uses a twist of Ultra-linear (ARC has their version) or Pentode (Mac and Quad have their versions). Ultra-linear was invented in 1938 and made famous in the 50’s. Not a lot has changed.

There is a booklet written about this by Scott Frankland for Sonic Frontiers many years ago that is FABULOUS. Download it here

http://ken-gilbert.com/images/pdf/taste_of_tubes.pdf


See you guys at 11.  I will get there at 10:30.  The phone number is 909-931-9686.

Cheers!

Kevin
Kevin, it was great talking with you yesterday. Say Hi to everyone there today from me. Hope it goes well. Have a good vacation.
It was a fun time. We had six people in attendance. I had the $8500 VSI75 set up, a DiaLogue Premium integrated ($3399) with KT150 tubes (add about $400) and an HP integrated ($4399). All of them had been on for days, all had tubes that test new. All of them sounded fabulous.

At first we listened unblinded, and I think everybody liked all of them, but no real conclusions were made. I had a feeling people were being effected by what they THOUGHT should sound best.

So I decided to make it a blind comparison by blocking the amps from view with cardboard and when I switched from one amp to another I asked that people look away so they could not "figure it out". I played the DiaLogue w/KT150’s first, the HP second, then the VSI75, and asked them to pick their favorite. The votes were as follows:

DiaLogue Premium w/KT150’s 4 votes
HP with stock EL34’s 2 votes
VSI75 0 votes

But don’t read too much into that. This is not to say it’s night and day between any of them. The VSI75 is fabulous...especially if you leave it on a lot and it’s hot.   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.  
   
I would be ecstatic with any of them, and would prefer them to a stack of reference solid state separates.


I want to thank all those that attended including Bob Levi from the LA Orange County Audiophile society.
Kevin,

Just wanted to thank you again for your hospitality and openness to organizing this shoot out. I will put together some thoughts and post in a while.