Audio Research VS115 power amp
LDA -- Sat, 01/08/2011 - 12:59
Hello all;
I'm considering buying a new ARC VS115 amp to drive my Proac D28 speakers. I'm using an old Sonic Frontiers Line 2 as the line stage. The listening room is about 40 square meters and I am usually listening to classical, opera, classical jazz, vocal jazz and folk.
If you could give me your ideas about the mentioned amplifier as well as its marriage with Proac I would deeply appreciate.
Best regards,
LDA
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Hello guys;
Unfortunately it seems that my case is not just a tube failure. Yesterday my dealer sent a technician to my house. We tried to swich all the tubes in the left channel with ones in the right but nothing changed.! Still a giant voltage (almost 20 Volts!) was measured. The guy made a lot measurements with great patience and the only finding was that the resistor in front of the V8 tube went bad. Why is that ? We dont know. He took a couple of photos and send them to ARC. Probably thay will replace the bad resistor, but to me the most imprtant thing is to find out the underlying reason of this failure. I hope ARC have an idea about that.
Well, I should say that I am a bit dissapointed about the reliability of ARC products. One of the reason that I decided to go with ARC is their product quality. After only 100 hours of use this kind of fault... But the amp was simply outstanding... Now I returned to my miserable waiting days back. Maybe today the dealer will give me an amp temporarily..
Best wishes to all of you.
LDA
Hi guys;
Could you please give the email address of the ARC technical support? I just wanted to write them about the amp, failure and I will ask the production date of the unit. I know my dealer already contacted with them but I just want to make sure about the repairing process..
Thanks a lot.
LDA
LDA...unfortunately, they do not provide an e-mail address for consumer enquiries. Your dealer will have an email contact so you can try to get it from the dealer. ARC does have a customer service phone number: 1-763-577-9700 (this is if youa re calling from within the US, from the UK, you will have to put the country code first and then dial 763-577-9700). Hope this helps.
cmalak. thank you for your reply. I know that there is no email address provided in their web site but basileM told that he wrote ARC about the failure of his amp. Also in some forums I read that folks write to ARC and ask technical/non-technical questions etc... There may be a secret email address I believe.. What say you guys?
LDA
cmalak. By the way, I know that you too had some problems with a few resistors in your REF110. I read it in another forum site. You only wrote that a couple of resistors went bad. Could you please give a bit more information about your specific case and the cause of the failure since mine may be very similar to yours.
Many thanks..
Regards,
LDA
Hi LDA...I had a 6550 tube fail and it couldn't hold it's bias. One day, as the I was listening to music, I heard a loud pop, and a trail of smoke come out of the amp. So i obviously turned the amplifier off and called my dealer. What had happened was the resistor in front of this tube had literally burst and acted like a fuse. My amp was still under warranty so I took the amp to my dealer. They talked to Audio Research and explained what had happened. Audio Research sent my dealer's Tech a replacement tube for the one that had gone bad and a matching tube for the opposite channel plus a replacement resistor. The Tech made the replacements but when he turned on the amp again a few more resistors blew. At that point, the amp was shipped back to Audio Research and they checked everything and replaced a few of the bad resistors and then retubed all the tubes and rebiased them and tested it and it was fine. It was at that point that they stressed that one should not turn any of their power amps off and then turn them back on without a minimum of 10 minute cool down period as that could cause bias drift and instability in the circuit. I probably had done that a few times before the problem occurred in my Ref 110, so not sure if that was the culprit but I mention it in case you have done so yourself. That was maybe a year and a half ago or so, and I have not had an issue with the amp since. Unfortunately, this is the nature of the beast with tube amps. Tubes go bad and sometimes they take out parts of the circuit with them. In Audio Research's case, they couple resistors to the output tubes to act as fuses so as not to damage the remaining circuit. Hope this helps.
Thank you very much cmalak. Its all clear now.. Thanks again..
Hello friends;
At last, they found the reason of the failure of my REF110. Actually its not a surprise cause. This is exactly what cmalak and basileM mentioned a few days ago. Basically it is a tube failure and in order to protect the rest of the equipment the resistor sacrificed itself... ARC will send a new resistor along with a new tube; this is why they asked the reference number of the tube connected to the failed resistor. Well I am a bit relieved but still passionate..
By the way, they generally recommend the use of a voltage regulator so-called regenerator, with tubed amplifiers as they are pretty sensitive to the voltage alterations. My dealer says that this may be the source of this tube failure. As I mentioned before I only use seperate power conditioners from Systems and Magic for each component to clean the AC supply. They work pretty well and do not compress the dynamic passages. Now I am considering PS Audio Power Plant Premier as an option. Actually this unit is discontinued now but on the other hand it has already been proved to be a very good performer by the reviewers. In addition now they are selling it with a very reasonable price. Could you please share your ideas about it? Have you had any experiences with this unit feeding a power hungry ARC or other amp along with the rest of the system?
Your help would be very much appreciated.
Best wishes.
LDA
Hi all at this forum.
I read you with much interest, as a long run ARC owner.
I experienced a tube failure (V1) at 250 hours on my VS115 (a big shot and a white light): dealer fortunately changed the tube and two resistance for free.
Not anymore problem till now. Anyway, Cmalak's advise is very interesting.
Now the amp is powering a CD5 / LS27 line, and a PH8 will be the next upgrade over the SP9 Mk II phono stage.
As for the cables, Nordost Frey interconnects and speakers cables are on the way.
(Sorry for my bad english).
The one thing that needs to be emphasized here, is that the REF110 is an ultra-high-performance piece of audio gear and should be treated as such.
So..? Could you please be a bit more clear SundayNiagara?..
Any comment on the Power Plant guys?
Hello all;
At last, the amp has recovered from the tube failure. ARC sent a new tube along with three resistors related with it. I have been listening the system again for about 10 days without problems. By the way, I purchased the regenerator I mentioned before and Nordost Heimdall interconnets between my CD player, my pre amp and power amp. I meticulously compared these cables with a lot of cables including the DHLabs Revelations before buying them. With their wide open soundstage, elagantly transparant, delicate and very detailed sound Heimdalls easily outperformed the others. However, the cables I tested were demo versions (fully broken in ) and the dealer gave me the new ones, of course, after the purchase, but now the sound is unbelievably terrible.!! The worst sound I have heard since I had the REF110. The rounded, soft, absolutely non-fatigue sound is totally lost!. Trying to break in the cables for 24 h/d since last Monday but they are still very edgy, bright, harsh etc.. I just could not help my self and connected my old ones!...
Any comment about the break in period of Heimdalls would be much appreciated.
Best wishes to everyone.
LDA
The only thing you can do with the cables is hook them up to a cheap receiver & let them fly.
This is exactly what I did. I am just curious whether of not the sound I liked in the first place will come back. I hope I did not make a wrong choice..
Let them cook for 3-4 days & give them a try. I can't imagine they'll sound different from the demo set.
By the way, the sound is now (190 hours) somewhat lean or thin in the midrange compared to the one roughly 100 hours ago, even with my old interconnects hooked up. Especially violins have lost their body. Is this also a burn issue? cmalak, owner of a REF110, do you have a comment?
LDA...I own the Heimdall interconnects and speaker cables. Nordost cables will sound thin and shrill at first. They do need some time to break-in. Here's a suggestion. Borrow your dealers demo Heimdall cables again and swap them into your system. If you get the sound that you remember from the time you demoed them, then this will support the idea that your new cables need more break-in time. If your system is still sounding thin then the only other thing that has changed is your addition of the PS Audio power reconditioner. It may be that that is the culprit or that that unit itself needs break-in time. In which case both new Heimdalls and PS Audio Premier need time to settle in. If you take both your new cables and PS Audio out of the chain and put in the demo Heimdalls and all is well in the world than you have isolated the problem. If you take the new stuff out and swap in the demo Heimdalls and you are still unhappy with the sound, time to move on from the Nordost cables and get something else. Hope this helps.
cmalak, thank you for the reply.
Just to update the previous post; Yesterday I tried the new cables again after a few days of break-in. It seems that the basic shrilness has gone. Just a bit bright at the "fortissimo" parts of the brasses but it is not a problem. The mids were rounded and bold again with a detailed sounstage and crisp focus. I'll keep breaking in them for a few days more. The amp has just passed 200 hours of run. After 400 hours I will give Heimdall speaker cables a try.
By the way, I made several comparisons with/without PS Audio Power Plant. PPP was not responsible from the shrilness. In adddition, I did not notice any dynamic reduction even in the hardest passages. On the contrary, the bass was tighter and the sounstage was wider with PS. Just my observations... I'll keep making comparisons when I have enough time.
And , if you guys could give a quick look to my new thread (in Universal disc players) I would appreciate.
Regards,
I wonder how will be to matte the arc vs115 with kt120 with martin logan clx?