@fsonicsmith1 No need to apologize for being critical. I appreciate it. U made some very good points and the tubes had 660 hrs on them. All the tubes were purchased from ARC matched set. I even bought a brand new 2nd matched set from him that he also purchased from ARC. I would never buy these tubes from a middle man. I would rather pay 💰 a lot more for them from ARC knowing they will be the best out there and matched. 1 thing I did not do when they were warmed up for about an hour was check the bias on them. I did ask my seller if I needed to and he told me he checked everything out completely right before he shipped and said they should be totally fine. I also went by the meter that showed they were in normal operating range. I ordered the new KT150 with the exact number written on the tube from ARC and also new fuse and extra resistors. When John Rutan and his service tech comes to my home to do the work I will have him check everything out with them and see if they can check the tubes out and bring a tube tester also. The amps were bought from a member from here and I have spoke to him and texted each other for hours and he is extremely knowledgeable about these Ref 750s and explained everything I had questions about and many more that he brought up. Any questions I had he was always there for me. As a matter of fact he was the first person I contacted when this happened. And he was the first one who said it’s not a big issue. And told me exactly what to do and what to look for about the arching. And said it definitely does not need to be shipped to ARC for repair. As a matter of fact he boxed up all the tubes and made sure to number them and put them all back in there exact valve socket locations. And also told me to make sure there were all securely pushed down in place. I really don’t think there was nothing that he left out for me to do and explained everything I really needed to know and more. We also became friends and text all the time I know he will always be there for me also with any questions or concerns I may have. I even sent him my Straightwire Crescendo quad wired for my B&W Matrix 800s as they were Bi wired for my Krell FPB 600. He reterminated them for me. Changed and soldered the spades to Cardas to the exact size I needed for the binding posts on the REF 750s. Beautifully shrink wrapped the ends. .Custom made beautiful oak blocks that he mounted them too about a foot where they get connected to the 750s. BTW he is amd works as an audio engineer.
Audio Research REF 750 pre July 4 FIRE WORKS. TUBE ARC.
Well I just had time to finally hook up my new Audio Ref 6 se for the first time as I got it back from AR last week. So I waited patiently for my night off from work last night and was also very excited to finally hear that for the first my Audio Research REF 750s. that came with the KT 150s with 660 hrs on them. I was really enjoying the beautiful sound of these phenomenal amps for a few hours and called my wife up to hear how amazing Barbra Streisand sounded playing The way we were. I had all the lights off in my listening room and we were lost in the sound quality as my B&W matrix 800 speakers disappeared and melted also to the beautiful sound of her voice and when all of a sudden there was an explosion as I had first thought. The middle of the top KT150s there was a loud SIZZLE a FIREBALL and a loud POP !!!! And WHITE SMOKE and then cut off. We immediately jumped up and my heart sank as I yelled OMG. I jumped up and ran to my L amp and I pulled the plug while the R amp and speaker was still playing. I said WTF happened?? My heart sank in my stomach as the first thing I thought was now after all the anticipation of that night to finally arrive I was now devastated as I had no idea WTF just happened. I was numb. I finally calmed down some looked over the amp on top. Didn’t see no damage and texted my guy that I bought them from and he told me it sounds like a tube arc. He then told me to take all the top tubes out but u can leave the 2 inside ones in. He then said to carefully take off the top cover as I did. I turned the cover over and saw black underneath as I then turned it over I saw it was V10. He said now look at the resistors by V10 socket. Sure enough the wire leads were gone. He said your V10 tube is shot and u will need to replace the resistors by V10 socket. I said does it have to be sent to ARC ? As I just got delivered the REF 6SE that had been upgraded and just got it back from ARC on Tuesday. I couldn’t think now about packing up the Left Ch REF 750 and shipping it back to ARC. He said nope no need to. Just have the Resistors replaced and get a new V10 tube with the same number on it from ARC. And call your ARC dealer here in NJ to see if his technician can come to my home and replace and solder the new resistors back on. Put the new KT 150 in and you will be back in business. So now I am waiting for my ARC dealer to open this morning and hopefully he will tell me some good news. Just don’t understand how or why this happened? Has anyone else had a similar experience? Wow I will tell ya that it was a very scary thing.BTW I never owned a tube amp except for my REF6 SE pre so this is still very new to me.
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Bringing a tube tester for KT150’s can be an interesting idea. Problem is they require 600 volts at the plate, which almost no tester can deliver! Also, it is a good thing you live in a colder climate, because, as you mentioned the Ref 750’s can do double duty as a space heater if needed! Not trying to be negative here either (like other posters have also mentioned), but I sometimes wonder where ARC come up with these designs??? |
There has been a lot of negativity towards ARC for years on this Board, long before it's recent troubles, and as an ARC fan I have little trouble ignoring the naysayers. All that said, on this I agree. I bought my first ARC amp, a VS110 from what I gathered was a very wealthy and knowledgeable guy who had a collection of ARC amps. Years later after buying the VS110 from him I contacted him to say hello and he mentioned he had another ARC amp to sell. I lost the email and can't remember the model name/number but what I will never forget is looking it up and it looked like a welding machine. It was similarly vertical to the Ref 750 but far more industrial looking. Those of us that follow ARC closely recall some real duds, regardless of looks, in the VT range. They were almost universally panned sound-wise. They also were very difficult to bias without being an expert. I do wish ARC would not mount tube sockets directly to circuit boards. The implementation, finally, of fuses on the tubes as in my Ref 80S is welcome. VAC and others have built and sold monster tube amps with vertical designs but power is useless without reliability and user-serviceability. |
Even the biggest VACs still use only 8 output tubes per side, compared to 16 in each Ref 750! At that point IMO you really need smart audio-bias circuitry to continually monitor & regulate the bias of each tube and shut down problem tubes (hopefully) before they spiral into a smoke show. VAC went that way starting with their "iQ" series. I have 200iQ and Master 300iQ now, and trust them implicitly. I believe ARC also started using their own version in Ref 160 series. But the Ref 750...yeah that’s gonna be a tough one to keep running. The fuses in my Rogue Apollos did NOTHING to prevent the KT90 arc/short problem. I have also heard warnings about KT150 tubes. I would definitely move into KT120 or KT88. You need extremely reliable output tubes if you’re running 32 of them. |
@mulveling You are one of the most knowledgeable regulars on this Board. When you post, particularly in the analogue section, I read what you have to say. I appreciate your input here. |
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