$1.47 magic rings

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  • 02-06-2011, 01:43 PM
    phileserver39
    $1.47 magic rings
    Hey All,

    Happy Superbowl Sunday! Go Packers.

    Just wanted to share the most cost efficient improvement to my system (by a country mile). I was having issues with every set of tubes that I have used in my YS Audio Symphonies Plus pre. Sovtek LP & WA, "Groovetubes" (pieces of crap), Tung Sols and my newest set of JJ 803's. My pre has a 6x4 rectifier and 3 12ax7 tubes. Nothing ever sounded as good as I had hoped and I am confident that I have had realistic expectations taking in consideration the relatively little bit of money invested in said tubes. I always experienced a little too much noise, mildly sloppy imaging, and mushy bass. Oh, and I have always used the cheap metal, springed tube covers that never seemed to lock in place very well.

    So I discovered recently that there are things called "tube dampeners" which, some claimed, could improve all of my previous complaints concerning my preamp and it's tubes. I also discovered that all I had to pay was $15 for somebody's version of a tube dampener. $60 for a set of tube dampeners? Naw....I can do better than that....can't I?

    I went down to Lowes and picked up 4 heavy-duty grommets from the hardware section (NOT the plumbing section) and I must say that I guessed perfectly as to which two different sizes I needed (.79 cm for the 12ax7s and .95 cm for the 6x4 rectifier).
    They fit most perfectly- nice and tight without fear of cracking the tube.

    So far after 1 hour there is no burning rubber smell or smoke (this is why you don't want the plumbing version of the grommet). I only put two screws into the cover just in case I needed to quickly stop my pre from going up in a blaze of glory.

    Wow- tighter bass, imaging that starts to really "paint an audible picture" and much less noise. I can really crank my pre before I hear the faintest tube noise. There also seems to be less grain(?). BTW, I am coming into the pre from my new PS Audio Digilink 3 DAC which I freaking LOVE!

    Highly recommended mod for those with tube equipment.

    J
  • 02-07-2011, 08:51 AM
    E-Stat
    Quote:

    Originally Posted by phileserver39
    So I discovered recently that there are things called "tube dampeners" which, some claimed, could improve all of my previous complaints concerning my preamp and it's tubes.

    Glad you found out about them. Dampers have been found in Audio Research gear for around twenty years. Indeed, they reduce tube microphonics.

    Quote:

    Originally Posted by phileserver39
    I also discovered that all I had to pay was $15 for somebody's version of a tube dampener. $60 for a set of tube dampeners? Naw....I can do better than that....can't I?

    Not if you're comparing apples and apples. Some, like Herbie's Dampers are more than merely a grommet and work better than the ones I've used before. Here is how they appear.

    rw
  • 02-07-2011, 09:16 AM
    Feanor
    Coolers
    As a matter of interest, on my Sonic Frontiers pre I use Pearl Tube Coolers. They mainly claim to extend tube live -- up to three times(!), and they will have some damping effect too.

    They are available from Parts ConneXion, here, and possibly elsewhere. I was able to get mine on sale a couple of years ago for $5 each; I need six for the 6922s in the Sonic Frontiers, but $30 plus tax and shipping wasn't bad.

    http://www.partsconnexion.com/media/...cess_62445.jpg
  • 02-07-2011, 10:18 AM
    Mash
    $25 Heat Solution
    Tubes that are a little too hot can have subtle problems.

    I use AC-powered laptop chillers underneath my tube pre's. They switch on with the pre, .....and I do not sit real close.

    Alternatively you could fit a larger slow-turning fan & a duct. The chillers are simpler.

    I have found no problems that suggest I need "tube dampers".
  • 02-07-2011, 10:33 AM
    E-Stat
    Quote:

    Originally Posted by Feanor
    They mainly claim to extend tube live -- up to three times(!), and they will have some damping effect too.

    What kind of small signal tube life do you get? I leave my Manley DAC on 24/7 and replace the two 12AU7s once a year. The 6922/7308s in my preamp typically last about 6000 hours. As for damping effect, I'm not convinced that thin hollow metal is the optimum material for damping vibration and microphonics.

    rw
  • 02-07-2011, 12:47 PM
    Feanor
    Quote:

    Originally Posted by E-Stat
    What kind of small signal tube life do you get? I leave my Manley DAC on 24/7 and replace the two 12AU7s once a year. The 6922/7308s in my preamp typically last about 6000 hours. As for damping effect, I'm not convinced that thin hollow metal is the optimum material for damping vibration and microphonics.

    rw

    I don't know -- I only run the SF about 2-3 hours a day on average, (although the it keeps a trickle voltage through the tubes at all time). I've had the SF preamp for less than 3 years so I've only logged 2500 hours or so of actual play time. I've had the the Pearl Coolers all but the first month or so. Most of the tubes I'm using I've had 2 1/2 years or longer and I've never had a frank failure nor any obvious deterioration. Also, my gain tubes were used, not NOS, and I don't know how much use they had before I got them.

    Pearl insists their coolers deliver at least twice the life even with cool-running tubes, (like the 6922). They make no particular claims about damping but the coolers are folded copper and fairly substantial in weight; they held in place by compression bands. So I would expect that there is some damping effect; in any case I haven't noticed anything like microphonic symptoms.
  • 02-07-2011, 01:06 PM
    E-Stat
    Quote:

    Originally Posted by Feanor
    I don't know. I've had the SF preamp for almost 3 years and the Pearl Coolers except for the first month or two. Most of the tubes I'm using I've had 2.5+ years and I've never had a frank failure of any tube nor any obvious deterioration.

    I too, have never had a small tube failure in 30 years' worth of experience. Most small signal tubes just don't generate much heat. I have, however, had two 6550s go supernova on me over the years!

    rw