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?
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?
Showing 3 responses by pinwa
I've replaced all the tubes in the 5SE including Electro Harmonix 6H30PI in place of the 6N6P that I personally think sound better. I'll post here again if the problem recurs. It might take a few weeks to be sure it is fixed. If I don't post again you can assume the problem was with the tubes. And thanks for all the suggestions. |
@mulveling I did put the stock tubes back in the 5SE, a matched quad of Electro-Harmonix 6H30's plus one in the rectifier position along with a Tung-Sol 6550. That did fix my problem (so far fingers crossed) with the 5SE triggering the Fault Protection mode on the PS Audio BHK 300s. So that was great advice. However, my system sounded flat and less dynamic after that change. I thought the tubes simply might need more burn in but a couple of weeks later I just wasn't happy with the sound. I put a new set of 6N6P tubes and like magic the sound I wanted and love was back. I've now stockpiled 4 sets of 6N6P tubes and will plan on swapping them out around $1600 hours. They are cheap enough that is no big deal. I've never read about switching in a KT88 or KT90 instead of the 6550. Does it make a sonic difference? I have an Allnic H3000 phono stage and rolling the rectifier tube makes a pretty big difference in the H300. |