I got myself some of these sockets. They look nice and high quality, I was hoping for them to be better than the usual cheap loose wobbly kind.
It turns out they are on the other extreme. I only have 2 types of octal tubes, a Sovtek 5AR4, and a pair of Guiguang KT88. I can get the 5AR4 to sit all the way in, but I need tool to remove it afterwards. The Chinese KT88 I can't even get them all the way in.
I was hoping to to remove the nuts on the pin to loosen the jaw. I tried with a small plier but it won't do. I don't have (and never seen) a wrench that tiny
Any tips to loosen them up? I was pushing the tubes in and out but I think I will eventually break something.
Anyone have experience with them? Will they eventually loosen up? Or am I better off with the cheap wobbly kind?
It turns out they are on the other extreme. I only have 2 types of octal tubes, a Sovtek 5AR4, and a pair of Guiguang KT88. I can get the 5AR4 to sit all the way in, but I need tool to remove it afterwards. The Chinese KT88 I can't even get them all the way in.
I was hoping to to remove the nuts on the pin to loosen the jaw. I tried with a small plier but it won't do. I don't have (and never seen) a wrench that tiny
Any tips to loosen them up? I was pushing the tubes in and out but I think I will eventually break something.
Anyone have experience with them? Will they eventually loosen up? Or am I better off with the cheap wobbly kind?
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Tube socket contacts all need some "flexibility" to accomidate tube insertion due to tolerences in the pins.
Those sockets pictured are not something I'd want to use.
Bad design.
Those sockets pictured are not something I'd want to use.
Bad design.
Actually the design is too good 😀
You might have some luck using something like an ice pick to bend the contacts slightly so they don't grip as tight. A small nut driver should work to loosen the nuts.
You might have some luck using something like an ice pick to bend the contacts slightly so they don't grip as tight. A small nut driver should work to loosen the nuts.
"Ignition wrench set". Amazon easily finds down to 4mm and 5/32", even 2.5mm.
Craftsman 20 Piece Standard SAE & Metric MM Midget Ignition Wrench Set
Moody Tools 57-0122 16-Piece English / Metric Mini Open End Wrench Set
SPEEDWOX Mini Wrench Set Metric SAE Ignition Wrench Set Open End and Box End
Lichamp Precision Socket and Open-End Wrench Set, 27-Piece
Mini Wrench Set, 5 Piece Set
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I used a soldering iron tip to poke them. Individually the tension on each socket isn't too bad, but 5 of them can grip the 5AR4 real tight. The 7 pins on the KT88 made it impossible.
These don't fit real tubes well, but they fit each other well like lego. Right now I have them stacked in a column and heated in oven on 60-70 deg C for an hour or so. We'll see what happen.
These don't fit real tubes well, but they fit each other well like lego. Right now I have them stacked in a column and heated in oven on 60-70 deg C for an hour or so. We'll see what happen.
Those are actually meant to be adjustable to deal with octal base tolerances (and there are some, given the 85 years of production all over the world)
After the oven, an unexpected outcome was I was able to loosen the nuts holding the metal contact. It turns out the tension is perfect. The problem is the center guide hole is too small.
I tried a needle file it seems to take forever to do anything. I don't have a bench vice to hold the socket in place to drill it, also I suspect I need the ceramic tiles bits. I might have to chuck this if there is no way to enlarge the hole.
I tried a needle file it seems to take forever to do anything. I don't have a bench vice to hold the socket in place to drill it, also I suspect I need the ceramic tiles bits. I might have to chuck this if there is no way to enlarge the hole.
With all that bothering and fussing, I'd toss those damn things in the trash and get something more traditional.
It's not normal to have to go through all that stuff.
It's not normal to have to go through all that stuff.
After more bothering and fussing, I have a better understanding now.
With regard to the center hole, I'm not sure it is the socket's fault now. With the Sovtek tube, it actually fits perfectly. It might be the Chinese tubes that have the center pin too fat. I only have these 2 octal tubes to try so it is difficult for me to draw any conclusion.
But I acted a little impulsively, I have a 12mm ceramic drill bit and shaved off a few mm of the entrance of the center pin. Now the Chinese tubes go in almost completely save for an mm or so.
With regards to jaw tension, it is actually very tight, at least with the Sovtek tube. With the Chinese tube it is almost perfect. I have read that at least some Chinese tubes have metal pins that are a hair too thin (metric/imperial thing), causing contact problem in some amp, I guess it is true. After more rocking and twisting they appear to loosen up a little. Now I need a lot of wiggling to remove the tubes, but no tool is needed and I consider the socket usable. A very secure fit is not a bad thing to have.
With regard to the center hole, I'm not sure it is the socket's fault now. With the Sovtek tube, it actually fits perfectly. It might be the Chinese tubes that have the center pin too fat. I only have these 2 octal tubes to try so it is difficult for me to draw any conclusion.
But I acted a little impulsively, I have a 12mm ceramic drill bit and shaved off a few mm of the entrance of the center pin. Now the Chinese tubes go in almost completely save for an mm or so.
With regards to jaw tension, it is actually very tight, at least with the Sovtek tube. With the Chinese tube it is almost perfect. I have read that at least some Chinese tubes have metal pins that are a hair too thin (metric/imperial thing), causing contact problem in some amp, I guess it is true. After more rocking and twisting they appear to loosen up a little. Now I need a lot of wiggling to remove the tubes, but no tool is needed and I consider the socket usable. A very secure fit is not a bad thing to have.
Secure contacts are good, yes.
Floating terminals are good, yes, they allow for small variances in tubes.
Chinese tubes, I don't ever use them.
Floating terminals are good, yes, they allow for small variances in tubes.
Chinese tubes, I don't ever use them.
I bought some cheap B9A sockets off ebay and they were so tight as to be useless. i got an ebay refund and told to bin them.
Eagle model for those sockets.
If anyone needs the models for these CMC sockets let me know, i can send you a eagle library that i made for them.
If anyone needs the models for these CMC sockets let me know, i can send you a eagle library that i made for them.
to loosen such type of sockets i use a metal envelope tube, takes a few insertions to loosen up....
but what annoyed me no end are those ceramic sockets that have a tendency to break the center guide plastic pin....that is also an issue not talked about much...
but what annoyed me no end are those ceramic sockets that have a tendency to break the center guide plastic pin....that is also an issue not talked about much...
With all the labor going into making a tube chassis, its rediculous to even have to fool with messing around with tube sockets.
I simply get mine from here Vacuum Tube Accessories - Sockets | Antique Electronic Supply
and never had an issue with them.
I simply get mine from here Vacuum Tube Accessories - Sockets | Antique Electronic Supply
and never had an issue with them.
i prefer to use surplus Cinch octal connectors pulled out from old surplus military equipment....where i can get them, much better than most china jobs...
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Indeed, Belton is what I meant!
BELTON Engineering
Affordable, solder really well and have the play that I consider fundamental to avoid any stress on the valves!