Tube Socket help, I'm looking at a few, but not sure which material to buy?

[Pioneer621]

Hello,

I have a question for the knowledgeable tube socket people out there!

I found a few cheap sockets that look like they will do the job, but which one is best?

I need to replace a tube socket in a Fender Vibro Champ guitar amplifier. The original tube socket over heated in a spot and the insulation is now conductive creating a resistive short from the output pin to the heater pin on a 6V6 tube. I scraped a groove out of the burnt part until I got into a good portion of the socket insulation, & could not read any resistance with my ohm-meter afterwards, & the amp works fine, but I want to replace the tube socket since it was heated to that extent & I believe it is no longer reliable. I am thinking a previous output tube shorted and caused it to overheat & that’s what led to the problem, as everything else in the amp seems fine & sounds good after I separated the short circuit. (the amp was missing the rectifier tube & output tube when brought to me so I can't test any tube for shorts).

Here are the sockets I found on ebay that I will probably be buying, but I would like to know which one is a better quality or are they about the same (the price is the same). I know one is ceramic, but I am unsure of the other, & one says Micalex. Can someone tell me which is better for my application? Seems like the ceramic would be a good choice, but I really don’t know.

I don’t work on much tube equipment (still learning as I get the stuff brought to me for repair) so my knowledge is limited on tube sockets, the ceramic ones look good, but the black ones look almost the same as the original ones, the brown ones look really close too. I think the ceramic (white) ones would withstand more heat, but I don’t know for sure, if the ceramic is better I will use them.

Both the output tube (6V6) & rectifier tube (5Y3) use the same socket, I think I may change them both so they match, but the rectifier socket still looks great.

Here are the ebay item numbers to the sockets I am looking at getting (I could not seem to get the links to work, so if you can, the item numbers can be copy & pasted into the ebay search):

Here is the white ceramic socket:
8 pin ceramic octal tube socket bottom mnt 6L6 6V6 EL34
Item number: 150383787642

or

Here is the black one that looks very similar to the original brown socket in the amp (I don’t know the material of this one, maybe bakelite or something):
8 pin octal tube socket 1 1/16" top mount 6SN7 6V6 EL34
Item number: 150383787634

or

I seen this one as well, it says its made out of Micalex (not sure what that is or if it’s a good insulator) although it may be a tight fit, but I already figured I may have to make the chassis hole slightly larger to accommodate the new sockets anyway, so I guess that’s not a big issue:
8 pin Micalex octal tube socket for 6V6 6L6 EL34 6SN7
Item number: 150383787638


There all the same price so whichever is best for my application I will get. I hope someone with knowledge on this can help! I do appreciate it! Thank you all & I hope to get some info on this. Take care! Pioneer621

[Geek]

Hi,

Honestly, any of those will likely outlive you.

We're not takling 6146B's in a VHF transmitter... just a 6V6 class guitar amp

Cheers!

[Ty_Bower]

I've used the Belton sockets, which are made of Micalex. They're not too expensive and I've been extremely happy with how nice they are. They seem better than the slightly less expensive generic ceramic sockets.

[wrenchone]

One thing to remember is to be careful when you're soldering on any of those sockets. I had to steal a contact from a spare socket to fix a place where the solder got into the pin contact in one position, preventing the tube from being inserted (too much solder/cooking the connection too long). It was easy to fix, but I hated having to rob Peter to pay Paul, as it were. Now I have a spare Belton 9-pin that's good for nothing but supplying contacts to fix future screw-ups.

[Ty_Bower]

Originally Posted by wrenchone

One thing to remember is to be careful when you're soldering on any of those sockets. I had to steal a contact from a spare socket to fix a place where the solder got into the pin contact in one position, preventing the tube from being inserted (too much solder/cooking the connection too long).

I've found that giving up on my cheapo Radio Shack $5 soldering iron has improved the quality of my work considerably. It always ran too hot, scorching circuit boards and oxidizing the tip. The burnt tip was nearly impossible to keep wetted with solder, resulting in lousy connections.

I discovered this Aoyue 936 soldering station for less than $45 shipped. It's so much nicer to use, and was well worth the price. It is a real temperature controlled station, so it is much easier to avoid cooking the thing you are trying to solder.



http://s69.photobucket.com/albums/i4...o/aoyue936.jpg

[tubelab.com]

The original tube socket over heated in a spot and the insulation is now conductive creating a resistive short from the output pin to the heater pin on a 6V6 tube.

This is a common failure in a guitar amp and it is usually caused by operating the amplifier with out a speaker, with the wrong impedance speaker, or unplugging the speaker while playing. This is less likely in a Vibro Champ since the speaker is built in. It can also be caused by dirt and humidity build up. The plate voltage (pin 3) can swing to almost 800 volts when the amp is cranked into clipping, and the heater (pin 2) is grounded.

I try to use the old style white creamic sockets in guitar amps since they are immune to being carbonized (burnt, what happened to your socket).

[Sendy]

Aspects of the exchange of slots:
1. mechanical compatibility
2. quality insulating and temperature resistance - for power tubes is very good ceramics, glazed ceramics better
3. quality and lifetime of contacts, must be flexible and not brittle, the shape of contact, material, plating, etc..

[wrenchone]

Ty, I'm using a Weller WTPC temperature controlled iron. The problem was too much solder applied to the lug, and it wicked down into the socket contact. Working on the chassis all the time with it tilted on its side and all the lugs in the horizontal plane would have helped prevent the mishap. Anyway, it's fixed, and the amp is working. More about that in the "Kingfisher" thread.

[richwalters]

In my opinion the worst oct sockets in the business; top mounted chinese octal with flange. NoWay can 6550 /6L6 types stand straight inthese sockets unsupported without a champagne or jock strap.

[Pioneer621]

Thanks for the responses everyone!

Hi,

Honestly, any of those will likely outlive you.

We're not takling 6146B's in a VHF transmitter... just a 6V6 class guitar amp

Cheers!

Geek, yeah I figured they were not too critical in a small guitar amp such as this, but was curious as to which one would be best. Yeah, high frequency transmitters would probably be more critical.

I've used the Belton sockets, which are made of Micalex. They're not too expensive and I've been extremely happy with how nice they are. They seem better than the slightly less expensive generic ceramic sockets.

Ty_Bower, I did see those Belton sockets but was unsure if they were what I needed, they look very similar to the factory ones in the amp, so my guess is they would work fine. The Belton sockets actually look very much like the brown ones I was looking at on ebay, but not sure if they are Belton, but they do say Micalex, not sure if they are the same quality though.

One thing to remember is to be careful when you're soldering on any of those sockets. I had to steal a contact from a spare socket to fix a place where the solder got into the pin contact in one position, preventing the tube from being inserted (too much solder/cooking the connection too long). It was easy to fix, but I hated having to rob Peter to pay Paul, as it were. Now I have a spare Belton 9-pin that's good for nothing but supplying contacts to fix future screw-ups.

wrenchbone, I will definitely be careful while soldering to the connection pins, I have seen the solder wick down into other connectors & the stuff would not plug in! So I understand what you are saying. At least you have a spare socket for parts incase you need it, so it will not go to waste, never hurts having spare parts around!

This is a common failure in a guitar amp and it is usually caused by operating the amplifier with out a speaker, with the wrong impedance speaker, or unplugging the speaker while playing. This is less likely in a Vibro Champ since the speaker is built in. It can also be caused by dirt and humidity build up. The plate voltage (pin 3) can swing to almost 800 volts when the amp is cranked into clipping, and the heater (pin 2) is grounded.

I try to use the old style white creamic sockets in guitar amps since they are immune to being carbonized (burnt, what happened to your socket).

Tubelab.com, good info to know! The amplifier is not mine & the owner if I am not mistaken purchased it in this condition, so I am not sure how it was previously operated, could have been used without a speaker or with wrong impedance and such, I don’t know, it was brought to me like this so I could take a look at it and repair what was needed.

I was thinking the ceramic socket would work ok in this amp, so I am leaning towards that one, but still not sure yet. If it will help prevent this problem in the future, it might not hurt going with ceramic.

Aspects of the exchange of slots:
1. mechanical compatibility
2. quality insulating and temperature resistance - for power tubes is very good ceramics, glazed ceramics better
3. quality and lifetime of contacts, must be flexible and not brittle, the shape of contact, material, plating, etc..

Sendy, I am trying to find one with similar mechanical dimensions so it will fit, but if I have to make the chassis hole slightly larger I don’t think that will be a problem, but I would like to find one that will fit. The ceramic one I am looking at seems to be very close to the diameter of the one I will be replacing.

I think the ceramic one would be a good choice & I think I may go with that.

As for quality I am not sure with the ones I am watching on ebay. They are low cost so I assume quality is not the greatest, but will it be good enough for the guitar amp I am putting them in?

In my opinion the worst oct sockets in the business; top mounted chinese octal with flange. NoWay can 6550 /6L6 types stand straight inthese sockets unsupported without a champagne or jock strap.

richwalters, are you saying the sockets I am watching on ebay are the worst sockets to get? They are low cost so I am sure quality is not the highest, but will they work for my application? I am thinking of going with the ceramic one, as it looks like it will fit fine & the insulating should be good & will be fine with heat. If the one I am looking at on ebay (Item number: 150383787642) is not a very good quality socket & may not hold the tube in well, do you know of a good socket I could get for this amp that is not too expensive?



I was going to order a couple today, was going to go with the ceramic as it seems they are a good choice for the power tubes & should not have any problems, but after reading richwalters post it got me wondering if they are going to hold the tubes in place without any trouble, I would hate to find out the tube slipped out of the socket, the tubes seem to fit nice and snug in the factory sockets, hopefully these sockets on ebay will hold them in equally well?

I think I am going to go with the ceramic ones on ebay (Item number: 150383787642); they seem cheap enough to try out. Anybody have experience with these particular sockets? Hopefully they will work ok, I think they will.

I thank you all for the information & it definitely helps! I guess it kind of comes down to quality & hopefully the ceramic one will be good enough. I think I will wait until later today to buy them so I can maybe get some more info, but if not, the price is pretty low so I may just grab two & see what I think after they get here.

Again, I thank you all very much!