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Problem with Ref 5SE

I recently purchased a 5se and took delivery the other day. Did not get a chance to open it up until last night. Upon installing it into system I switched it on and after it warmed up, I was very much interested in hearing how it sounded against my current 27. After listening to several tracks with the 27 I switched pre's and after a couple of minutes playing a CD I got some noise, almost a loud static sound coming from the right channel. It was not effected by changing volume controls or input selector. It went away after 10-15 seconds and then returned. At that point, as it was late, I shut everything down and figured I would take another look in the morning.

This morning I removed the top cover and pulled and reset the output tubes and then the power tubes. I fired it back up and still had the 'static' sound but now it also had a humm, like an impedance type hum and constant. I do not believe that the humm was present last night as it is quite noticeable. 

The static type load noise seemed to have abated after the unit warmed up after maybe 15-30 minutes.

Can I assume that perhaps a tube was damaged during shipping? Do you ARC guys think a new set of tubes will fix this issue or am I looking at something more severe? Any additional suggestions to try and pin this down?

I rerouted the IC going to the amps to get them further away from source IC's and no help...

I am a little bummed, as my initial impression it that it is a leap from the LS27, my current...
stevea11757
stevea11757's avatar
stevea11757 OP
130 posts
 
I tried plugging the amps into wall and the pre into my PS Powerplant and then the opposite, amps into PP and pre into wall. The 5se is replacing a LS 27, also a tube unit and I had no issues with that set up.

Ordered a full set of tubes and will be trying that out in a couple of days. While at the moment I do not have any other power cords to swap out as it is a 20a but will look today and see the cost to replace with another power cord. This is turning out to be a costly endeavor...
testpilot
991 posts
 
I assume that you bough the 5SE used.  Did you contact the previous owner and ask him if he had the same issues?  There will always be a bit of tube rush noise coming from speakers, but nothing should be heard from the listening position. 
ghasley
2,544 posts
 
Ive had several ref 5se’s, running into multiple different amps (arc, pass, even a shindo) and they were always dead quiet with my 96db speakers. You need to send it to Arc for service.
larryi
4,344 posts
 
Have you tried all of the various grounding options?  Have you tried a cheater plug on the main power cord, etc.?  Hum is usually a grounding issue.  Hum, particularly hum in both channels can be caused by a filter capacitor in the power supply going bad.  Both the 6550 and 6h30 tubes are in the power supply part of the linestage, so they are suspect as well.

The static type noise that goes away after the unit is on for a while can also be a capacitor issue or an issue with tube sockets.  Sometimes poor connection in a socket goes away when the unit is heated.  Your re-seating of the tube curing part of the problem suggests that this might be the case.  I would try cleaning the socket and pins of your tubes.  If noise problems aren't completely cured (good tube linestages  are dead quiet), you should send it in for a check up.
stevea1298's avatar
stevea1298
48 posts
 
ghasley

That is a definite possibility, but will wait until the new tubes come in and try that, if sound remains I guess in it will go.

I did go back up late last night to see if it was something that I can live with, from listening position, once the music starts the 'noise' disappears and only reappears between tracks, even soft passages it is really not noticeable.  My speakers Shahinian Hawks are 87db with a nominal impedance of 6 ohms.

Previous owner has said it was dead quiet in his system.

I am going to hold off judgement until I get new power plant installed, then new tubes and then considering a aftermarket power cable, although the factory seems pretty substantial. 

Hopefully one of these will quiet the beast.

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