Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: yorgle on October 21, 2020, 02:59:15 pm
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On all of my builds so far, I've used #4-40 machine screws and nuts to bolt tube sockets to the chassis. Once I'm satisfied that I don't need to take things apart again, I put a dab of superglue on the exposed threads/nut and that has worked well for my limited, living room use. But I wonder how that would hold up if the amp were being dragged/banged/kicked/dropped about to and from gigs. What do the grey-beards here use?
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I use 4-40 but I just tap the chassis. I don't use a nut. And I don't abuse my amps by playing them! :l2:
But, if the amp were being dragged/banged/kicked/dropped about to and from gigs, I would put a drop of Loctite thread-locker on the screw threads then put a kep nut on the screw. Probably a good idea for every screw in the amp, especially on transformers.
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I have a big grey beard so I guess I have to answer - I use kep nuts throughout the chassis. #4s for 9 pin sockets and 4s or 6s for octals, 8s for trannies. My amps stay home, but if I did tote them around I'd prefer the Loctite. I've used that on bicycles and motorcycles for years with good success. One of my bikes is a vintage Triumph - that thing needs lots of Loctite. :icon_biggrin:
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I use 4-40 but I just tap the chassis. I don't use a nut. And I don't abuse my amps by playing them! :l2:
But, if the amp were being dragged/banged/kicked/dropped about to and from gigs, I would put a drop of Loctite thread-locker on the screw threads then put a kep nut on the screw. Probably a good idea for every screw in the amp, especially on transformers.
I thought you used rivets. Maybe my memory is gone.
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Oh no. Never used any rivets.
http://sluckeyamps.com/supro/supro_02_big.jpg
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I use bolt, lock washer and nut,
Never rivets.
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I started with nuts n bolts n washers....bought rivets, gives it that '40s feel :icon_biggrin:
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...I use kep nuts...
+1.
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Kep nuts here also.
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It's include kep nut in my answer 'cause they are nut with lock washer.
In other word, bolt and nut is not enough to stay tight over years
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I use a lock washer, and locknuts. No loctite, and always worked great.
I started doing this after I read a document from Rod Elliot about earthing:
https://sound-au.com/earthing.htm
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I use a lock washer, and locknuts.
For tube socket, wich is the subject ;
It's like using a belt and suspenders to hold your pants no ?
If you want to use locknut, regular flat washer is enough to hold any mechanical stuff.
Teeth or lock washer is a must for electrical connection to "bite" into the metal and ensure a good contact and to hold nut always tight.
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It's like using a belt and suspenders to hold your pants no ?
Regular flat washer is enough.
hehe Yes, I guess you are probably right. I connect my mains safety earths like this, see attachment, so I guess I got used to use both locknuts and lock washers.
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Your pic looks like a locknut and flat washer?
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Too much hardware for small job,
If you built a bridge this way it would cost so much that no country could afford it and it would be so heavy it would collapse.... :l2:
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Your pic looks like a locknut and flat washer?
Yes, it looks like flat but it's a lock washer. See how it's not flat touching the chassis, but stays somewhat above while the teeth are biting it
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Hahaha, yeah too much hardware for a tube socket I suppose.
Safety earth connection is another story, though, and regulations vary from country to country.
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for the 7 & 9 pin miniature sockets, i use 4-40 hardware with keps (k-lock) nuts and an internal tooth washer on the bolt head end.
for octal i use 6-32 with the same washer/keps nut/ compliment.
--pete
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Your pic looks like a locknut and flat washer?
Yes, Elliot recommends just that while acknowledging this earth ground setup as overkill. But FranciscoPerez is off topic: Elliot says this ONLY for the ground connection and not to be used for components such as a a tube socket, the topic under discussion: "Do not use the earth connection as mounting for any other panel or component - it must be dedicated to the task of providing a safety earth point. If a component mounting bolt is used, at some stage it may be disconnected by a service (or other) person, which means that the apparatus is unsafe until everything is (hopefully) put back where it belongs - this does not always happen."
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I use M3 fasteners for most all my 9-pin sockets, and standoffs.
It may seem a bit pedantic, but I think its far superior to 4-40. Im an American, and I think all metric threads are for the most part.
For small insulated turrets and terminals, they often have 2-56 threads, so I’ll usually tap the chassis to mount them directly using thread locker.
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+1 with Sluckey
When I have had to repair/replace sockets, and they have been riveted, can be a pain to drill out the rivet neatly. It was a common practice in Australia for a couple of manufacturers in the 60's and 70's to use rivets.
We're Metric in Aussie so I use an M3x6 with Locknut but it's fiddly. Don't mind the screws in Noval Skts as long as the chassis thickness is sensible.
Soulfetish "Pedantic" is good :laugh: :l2:
Regards
Mirek