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Tightening Tube Sockets

9/1/2005 10:46 PM
Scott Tightening Tube Sockets
What is the best method to tighten power tube sockets? I just got new amp, but I noticed that one of the power tube sockets tends to wiggle just a bit when I was changing power tubes. The amp works fine and sounds good, I was just thinking about preventive maintenance.  
Is it worth fixing?  
What the best way to go about it?  
9/2/2005 1:32 AM

There are two things going on here.  
The tube has to make good electrical contact, and the tube has to be held in place securely.  
If you ever inspected a tube socket sitting out in your hand, you often notice the pins are free to move around while still held captive in their slots. As long as they maintain a good grip on the pins, it doesn't matter of they can move about. The tube wiggles, but the pins never lose onctact.  
There are any number of different socket constructions. SOme have the pins slipped in and a small catch retains them, while others have the pins permanently molded into the plastic. Obviously the second type will be less likely to let the tube move around.  
So determine what exactly you are wanting to do here. When we talk of tightening tube sockets, we generally mean crimping the pin contacts tighter to improve contact, we generally are not referring to the natural sloppiness of the pins within the socket body of some sockets.  
It works, it sounds good, don't mess with it.
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9/2/2005 2:14 AM
Steve A.

Enzo said:  
It works, it sounds good, don't mess with it.  
My father always said: "If its not broken don't mess with it!"  
    It is usually the older amps that need their pins tightened. My old 1965 Pro Reverb project amp would have itermittent problems like the sound cutting out every now and then; retentioning the tube pins cured that particular problem. If the sound would fade out gradually I would double-check the cathode connections; I believe that problems with the plate pins would be noisy... or not. :(  
Steve Ahola
9/2/2005 11:16 AM
Mark Black

This does bring up a question of interest (to me at least):  
What is your favorite tool or method for tube socket retensioning?  
I have been favoring a large-ish pin with a big teardrop handle (hat pin?) for most power tube sockets and a suitable jeweler screwdriver for most preamp types. These of course inserted down along the backsides of the contacts to force them in a bit.
9/2/2005 5:14 PM
Thanks for all the great info eveyrone!  
Basically I'm not talking about the individual pin sockets, but the actual white plastic socket itself.  
If you check out this link:  
Pictured above is the type of socket I'm talking about. The white plastic base that sits in the metal retainer, is what is moving around. It looks to me that the white base just sort of sits in the metal base, and maybe there isn't a way to tighten it up more? The white base tends to shift just a bit from side to side when I put pressure on it. The lugs on the back side are securely soldered, and the pins of the socket appear to be making good contact with the tube pins and it's holding the power tube securely in place. It's just that since this is new amp, I'm wondering if this was something not caught at the factory and what (if anything) I should do about it?  
Just to be clear, I'm talking about the white plastic base shifting/moving around in the metal bracket... not the individual pins.  
9/2/2005 6:09 PM
Mark Lavelle

Sounds like a job for a tube retainer:  
I like the type on the left...
9/2/2005 5:49 PM

The plastic housing is usually kept in the mounting ring by crimps. The ring is bent in to keep the socket base from falling out. You might be able to crimp it tighter with plyers. It would have to be out of the chassis for that.  
It might be possible to take a relatively wide pin punch - 1/8 maybe - and a mallet and tamp the ring down on the socket somewhat to the same purpose.  
On the other hand, aside from the fact that it bugs you, what exactly is the problem it causes? I'd ignore it.  
I use several things to get between the walls of the pin holes and the pins themselves. We mentioned the dental exlorers and my o-ring seal pick from the autoparts store. But I also use a large safety pin - a diaper pin really - folded out. Those are the safety pins a couple inches long. Tiny jewller's screwdrivers also work often as not.  
Anything pointy.
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