2. amps-preamps
  3. 153086-109191

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...
128x128stevea11757
Ag insider logo xs@2x
cleeds
5,944 posts
 
motorheadflash

I would love to hear from other ref 5 and ref 6 owners and see if they have burn marks or melting marks over their 6550 tubes. Has anyone had a similar problem with the static, or the 6550 tube burning out?
The 6550 will wear faster than the preamp’s other tubes. Burn marks, melting marks, and a deformed plastic top are all signs that the preamplifier was not properly ventilated. I’ve had no such problems with my Ref 5SE, which I bought new. It sits on top of my rack, so airflow is unrestricted.
bdp24's avatar
bdp24
9,788 posts
 

Speaking of Roger, he recommended three feet of space above his RM-200 amp, which ran 6550 (or KT88) tubes.

But ARC has a new option for you. Right on schedule, the New! Improved! REF 6SE is now available. Step right up ;-) .

motorheadflash
10 posts
 
My pre amp and amp both sit on the top of a cabinet. They get plenty of ventilation. Same thing at my dealer. Both of his demos are on the top of a cabinet and not in a rack. When my pre amp has been on for an hour or so the area directly on top of the 6550 tube gets so hot you cant put your hand on it. With the brand new tubes from ARC the amp is dead quiet and sounds fantastic. It just runs hot. The demo at the dealer seems to run just as hot. The dealer has sold many ref 5 and 6's and experienced no problems created by the heat. 
I'm surprised that your 5 se has no signs of heat distortion on top of the 6550 tube. When you put your hand on top of the 6550 is it hot?
stevea1298's avatar
stevea1298
48 posts
 
I have not checked how hot the tube had been running, currently the top cover is unscrewed (so I was able to access tubes). If I get home early enough I will take a look around the tube and see if there is any evidence of prolonged high heat exposure.

Just got word that tubes are shipping today so I should have them on Thursday and be able to answer a lot of questions Thursday night.
Ag insider logo xs@2x
cleeds
5,944 posts
 
motorheadflash
I'm surprised that your 5 se has no signs of heat distortion on top of the 6550 tube. When you put your hand on top of the 6550 is it hot?
Yes, it gets quite hot, as all the Ref preamps do. But the plastic top does not deform - it has plenty of ventilation.
More to discover