[neep]

This "Key" will make sense later:




I bought a Rogue Perseus Tube Preamp about 8 months ago and it came with JJ ECC802S (12AU7) tubes. Being new to tubes, I decided to pick up a few quad sets and begin tube rolling. And that's where the story begins... (my apologies for the added drama)

This is a very bizarre issue so please bear with me as I try to explain what's going on. I actually gave Rogue a call and they weren't much help in troubleshooting which is why I've come here to give you fine people a crack at it before I send it back to Rogue.

**********
Here are the following tubes that I ordered from eBay as described by the sellers:

1. RCA 12AU7A PLATINUM GRADE Clear Top Tubes Matched Pair =E CC82 6189 5814A (bought a quad set)
2. Sylvania 12AU7A PLATINUM GRADE Tubes Matched Pair = (ECC82 5814A 6189) BALDWIN (bought a quad set)
3. GE- JG-5814A/12AU7- Grey plate- Horseshoe getter- made in the 50's (bought a quad set)

Here is the manual for my preamp:

http://www.rogueaudio.com/manuals/Perseus_manual.pdf

**********

When the new tubes came in, you could imagine my excitement. I installed quad set #1, powered on the preamp, and got an extremely loud buzz from the speakers (much louder in the left) with the volume all the way down on my preamp. What is even stranger is that with the new tubes installed, the volume knob AND balance knobs on my preamp became extremely noisy/scratchy when moved or even slightly wiggled, very much like a dirty potentiometer in a vintage receiver but LOUD. When I touched either of them, I could see the woofers going crazy popping in and out. And again, this would happen with the volume all the way down. I'm assuming this is a big indicator of something going very wrong.

At this point I thought, "bummer, must be a bad tube in the batch." But the problem occurred again with the next two quad sets. When a set would be installed, I'd get an alarming buzz out of speakers with the volume all the way down. I changed interconnects, triple checked my cables on both ends, and the problem remained.

The problem completely went away after installing the JJ tubes that came with the preamp. I mean GONE.

Curiosity got the best of me so I decided to install quad set #1 again, except this time I left a single JJ tube in position "1" (refer to key above). Guess what? Played completely fine. No buzz. Now I've tried every combination in each slot with a mixture of JJ's and the new tubes and my unscientific conclusion is that slot "1" is the culprit. When I say unscientific, I mean that whole-heartedly. My conclusion could mean absolutely nothing, but when I insert a JJ into slot 1 with any combination of the new tubes, the preamp is buzz free. Move the JJ to slot 2, 3, or 4, with any of the new tubes and the buzz comes back.

The holidays are here and I'm already tapped out on "me" money so avoiding sending it in would obviously be a huge help. What Mark said from Rogue is that sometimes the older tubes have less beefy pins so I should try and "tin" them with solder to make them a little thicker. This did not solve the problem. Another forum member said that proper contact isn't being made in the socket so try bending the tubes pins ever so slightly to create a more snug connection. This did not work either.

Any ideas guys? Help would be more than appreciated!

[Ericus Rex]

Have you cleaned the pins on the old stock tubes?

[rpf]

What Eric said.

I don't remember where I found this but it's useful:

"I use a soft brass bristle brush, and carefully "scrub" the pins. I then spray them with DeOxit D5, allow it to sit for 10 seconds or so, then wipe the pins with a paper towel. It works VERY well, the evidence can be clearly seen on a white paper towel. And it does reduce noise problems caused by dirty tube pins/poor socket contact."

Alternately, I've used an Exacto knife to gently scrap the pins.


Also, if the pre-amp is used, this advice from Jim McShane could help as it may be the tube socket (No. 1) that is primarily the problem:

http://www.audioasylum.com/audio/tubes/messages/25/253369.html



 

[geowak]

I purchased some bad NOS tubes once. Also I have read, but have not encountered, that there exists a fair amount of unsavory sellers who sell bad tubes or counterfeit tubes... I hope that is not your problem here.

[neep]

What Eric said.

I don't remember where I found this but it's useful:

"I use a soft brass bristle brush, and carefully "scrub" the pins. I then spray them with DeOxit D5, allow it to sit for 10 seconds or so, then wipe the pins with a paper towel. It works VERY well, the evidence can be clearly seen on a white paper towel. And it does reduce noise problems caused by dirty tube pins/poor socket contact."

Alternately, I've used an Exacto knife to gently scrap the pins.


Also, if the pre-amp is used, this advice from Jim McShane could help as it may be the tube socket (No. 1) that is primarily the problem:

http://www.audioasylum.com/audio/tubes/messages/25/253369.html

This is great advice. I appreciate all the help and it has lead me to believe that it is indeed the tube socket. Rogue recommended I try "socket savers" so I have some on the way. I'll be sure to check in and update this thread in case anybody else runs into the same problem. Thanks again fellas.

[mav52]

I think the key here is the OP's comment

The problem completely went away after installing the JJ tubes that came with the preamp.

  So to me it's not the tube sockets but the tubes he got from ebay.    I don't buy tubes from ebay since as a poster noted, there are some people out there selling fake and poor tubes.    I get my tubes from Kevin at http://www.upscaleaudio.com/

Me thinks you got some poor or old tubes

[Early B.]

You guys didn't fully read the OP's message. He said all of the tubes work fine, except in one slot, so the tubes are not the problem.

[mav52]

You guys didn't fully read the OP's message. He said all of the tubes work fine, except in one slot, so the tubes are not the problem.

Interesting then why do the original tubes work in all slots ?   

[Early B.]

Interesting then why do the original tubes work in all slots ?

Like you said, it's "bizarre." If the folks at Rogue can't explain it...

[neep]

I followed Rogues advice and bought some "socket savers" because they believe that poor contact is being made with the vintage tubes.

I bought 4 socket savers and used them in all positions with the SAME RESULTS. No change.

This to me means it's not a socket issue, right? If Rogue believes the problem was a poor connection with the vintage tubes, then installing the brand new socket savers should have fixed that issue... unless ANOTHER poor connection is being made between the socket savers and vintage tubes.

 

[Tomy2Tone]

I just put my Rogue Perseus back into my system after being boxed up for a while which included moving to a different house. I had some Tung Sol tubes that I left in the sockets during the move and when I began to plug everything back up I was getting a lot of static/hiss coming out of just the left channel.

I had some newer Psvane tubes still in their boxes and popped those in and it's all quiet now. I'm interested to find out what is causing the problem for you. Please let us when you do.

I'm sending mine in to Rogue in a couple of weeks to get the magnum upgrade. Did you buy yours already the magnum edition?

Wish you luck finding a solution!

[neep]

I just put my Rogue Perseus back into my system after being boxed up for a while which included moving to a different house. I had some Tung Sol tubes that I left in the sockets during the move and when I began to plug everything back up I was getting a lot of static/hiss coming out of just the left channel.

I had some newer Psvane tubes still in their boxes and popped those in and it's all quiet now. I'm interested to find out what is causing the problem for you. Please let us when you do.

I'm sending mine in to Rogue in a couple of weeks to get the magnum upgrade. Did you buy yours already the magnum edition?

Wish you luck finding a solution!

Hey Tomy, it's such a shame that I can't swap better tubes in because it's a great sounding pre even with very average JJ tubes. I think I'll send mine in and have the upgrades done, as well as make sure they take a look at this problem. I'll keep this thread updated.

[screener]

I had the upgrades done a few months back and it's definitely worth the wait. I'm running some 1950s Tung Sol tubes with no issues. I believe what Jim McShane said is good advice. Have Rouge take care of the volume control also.

Good luck and hope it all works out.

[Tomy2Tone]

I had the upgrades done a few months back and it's definitely worth the wait. I'm running some 1950s Tung Sol tubes with no issues. I believe what Jim McShane said is good advice. Have Rouge take care of the volume control also.

Good luck and hope it all works out.

That's great to hear screener!
My Perseus is currently at Rogue and should be getting its magnum upgrade and volume control this week.

Mind me asking what the rest of your system consists of? And if you've ever experimented with tubes besides the Tung Sols?

I'm always interested in knowing what works for people. I have a pair Salk SS8's that have the Raal ribbon tweeter and Accuton mid, currently using a DSPeaker dual core as a dac and some modded Crown xls 1500's amps in mono that have their own gain adjustment.

I've ordered some Mullards from Upscale Audio and some RCA's from Andy at Vintage Tube Services to try when the Perseus gets back. So far I've used Psvane and they seem to sound good but looking for something different.