Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: theundeadelvis on July 15, 2010, 06:39:17 pm
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Hey Guys, I'm building a 15 watt combo with an EF86 preamp tube. I'm wondering what's the best way to mount the socket to cut back on vibration since these are prone to microphonics? I've seen the shock mount socket Weber sells, but I wasn't sure if it's the way to go, or can I mount it on some o-rings? Any other suggestions? Thanks!
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O-rings are the best way.You can get some hi-temp o-rings from an automotive supply store.They use them primarily for air conditioning.They are usually red in color,red being hi-temp.
Usually one around the base of the tube where it contacts the tube socket and two more around the body of the tube.
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Thanks Psychonoodler! That's kind of what I was envisioning. I'll see if I can pick some up tomorrow.
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... otherwise you could compartmentalise the tube/chassis part from the rest of the cab somewhat with extra slabs of timber in between or something like that. I have seen a chassis where the EF86 socket is mounted on a separate piece of metal which is shock-absorbed from the rest of the chassis too.
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O rings is what TopHat does (actually for all their preamp V1 tubes). Seems to work. I have used the shock mount sockets and they work fine as well.
If you are not too far into your design, check out Merlin's book (Valve Wizard). He has some interesting information on the EF86 that can really change is noisy characteristics. He might have the info published on his web site as well.