Issue with Audio Research 5SE Preamp


For a couple of months now I have had a problem with my system that I have now narrowed down to my ARC 5SE Preamp.  The issue is intermittent and not reproducible and I'm not sure how I would describe it in a way that I could search for a solution.  Every so often, but not frequently, so lets say every 3-7 days, while I am playing music there will be a loud thump from my subwoofers and my PS Audio BHK 300 Monoblocks will go into Fault Mode as the protection circuit is triggered.  This issue has occurred with multiple different DACs and streamers so my conclusion is the problem is with the 5SE preamp.  Once I turn the PS Audios back on playback will resume normally and it may be many days before it happens again.  I assume if the BHK 300's didn't automatically turn off whatever is happening might blow up my speakers but the only sound is the loud thump from the subwoofers.

My full system is Eversolo A8 streaming Roon to an Holo May KTE connected by XLR to the ARC 5SE connected by XLR to the PS Audio BHK 300 Monoblocks connected to Magnepan 20.7s.  I also have a DBX Driverack PA2 connected to the second set of outputs on the 5SE and the subs are connected to the Driverack PA2.  I have a phono stage connected to the 5SE but it normally isn't powered on and the problem has never occurred when I am playing a record but that doesn't necessarily mean anything since I mostly stream.

Since the problem has occurred with other DACs and both of the BHK 300s are overloaded at the same time it seems like it must mean there is a problem with the 5SEs but I have no idea what they would be.  In general, the system sounds fantastic.

Has anybody run into anything like this before?

pinwa

I owned this pre-amp a few years ago, and one thing that is not mentioned in the owners manual is that the 6550 tube must be changed at 2500 hours, not 4000 hours indicated for the 6H30 tubes. I would suggest checking the hours and removing the cover and inspect the circuit board. I had let my 6550 go beyond the 2500 hours and it burnt certain areas of the board. Which I returned to AR to be repaired. I hope this isn't the case for you but I do recommend taking these measures, if anything to just check it off the list. 

 

 

OK.  Switching out the 6550 sounds like a good place to start.  The tubes have 1670 hours on them.  I am actually using 6N6P tubes instead of the 6H30 tubes that are standard.  I liked they way they sounded more but I wonder if they have a short life?  

 

I would call PS Audio and ask them what would cause the amp to shut down. Then I would have the pre-amp checked to see if it's passing DC to the inputs of the amp.

As others have suggested, Audio Research tends to run their tubes hard, shortening their life-expectancy.