[Starburp701]

I bought a used Hifiman EF-5 Hybrid Tube Amp as my first Tube Amp a little over a month ago and the tube socket is shot! It's always been unusually tight but it's gotten to the point where it won't seat properly and the left channel will go in and out if it's moved at all. I've rendered it useless and ordered myself a soldering kit I've pieced together through the outstanding DIY Begginers tread on here. Only problem is that I can't seem to find a tutorial or video on replacing PCB Sockets. There's plenty on guitar amps and what not but nothing for headphone amps.

If anyone can give me a little direction it would go a long way! I've already tried Deoxit5, toothpicks, tube amp socket cleaning kit, anything and everything to avoid surgery on the poor thing.

P.S. - I've also ordered an Alps Blue Velvet volume potentiometer to replace the current one. I got the idea from an old Hifiman EF-5 DIY thread and it has pictures of the wiring so I should be okay with that.

TL;DR
I am a beginner DIYer looking for advice/direction on changing out the 12AU7 tube socket out on a Hifiman EF-5. THANK YOU!!!

 

[tomb]

There are a couple of ways you can do this -
 
1. Use a hot-air rework station to heat the tube socket pin joints on the bottom of the PCB.  When the solder melts, it should fall out.
Clean up the holes with de-soldering braid.
 
2. If you think the socket is bad anyway, and want to replace it, then use some flush cutters to cut the PCB pins from the socket.  Then go back and remove each pin as you melt the solder joint (pull them out with a pair of needle nose pliers while applying heat with a soldering iron to melt the solder. 
Clean up the holes with de-soldering braid.

 

[Starburp701]

Thank you, tomb. I hit the off switch on the power box and left the stand switch on to drain it. Do you think that will be enough to safetly work on it without having to worry about getting zapped?

 

[tomb]

Thank you, tomb. I hit the off switch on the power box and left the stand switch on to drain it. Do you think that will be enough to safetly work on it without having to worry about getting zapped?

 
The amp section is fed with 18V.  You're not going to experience any discomfort from taking apart the amp section and working on it.
 
Yes, you probably need to be cautious with the power supply, since that plugs into the wall (110V).  There could be a couple of capacitors you might need to steer clear of, but I doubt that, too.  Anyway, the power supply is not the component that has the tube sockets.

 

[Starburp701]

The amp section is fed with 18V.  You're not going to experience any discomfort from taking apart the amp section and working on it.

Yes, you probably need to be cautious with the power supply, since that plugs into the wall (110V).  There could be a couple of capacitors you might need to steer clear of, but I doubt that, too.  Anyway, the power supply is not the component that has the tube sockets.

Right, I just remember reading you can discharge the amp by turning off the power block and leaving the amp standby on. I'm not worried about the DY-1.

The socket is split in half horizontally.. the top will wiggle and shows signs of being able to detatch but it definitely doesn't want to come off. I'm not gonna mess with it anymore

The socket doesn't come in until next week unfortunately but the Alps pot. comes in tomorrow. That should be simple.

Thanks for your help and have a great New Year!

 

[Starburp701]

[/IMG]

A few of these copper rings came off the pcb on the top and bottom... can I use a piece of solder wire to link the new pins to the place they need to go?

 

[tomb]

[attach]1784807[/attach]

A few of these copper rings came off the pcb on the top and bottom... can I use a piece of solder wire to link the new pins to the place they need to go?[/quote]

 
Yes, but I doubt that those copper rings are actually gone.  Even if they are, you probably have through-hole plating that will still work.  Try soldering a new socket in there first, and deal with it later if it turns out the circuit is not contiguous.  You can check this by reading -zero- ohms between one of the tube socket pins and the next part on the PCB that the PCB-trace from that pin connects to.
 
When you remove a solder joint, it can often leave a dull finish that may appear as if the copper pad was ripped off.  It can simply be the dull interior of the solder that's left.
 
If it turns out that you cannot solder one of the socket pins to the pads (your "copper ring") and the metal really is gone, the proper thing to do is use a spent resistor lead.  Solder it to the pin and then use a knife or file to scrape away the solder mask from the trace nearby so that real copper is showing.  Solder the other end of the spent lead to that.  Any PCB with ripped traces or torn up soldering pads can be fixed this way.
 
 
P.S. All ceramic tube sockets are two-piece and give the impression that they can come apart.  They do not unless the center pin is force-ably removed.  Plugging in an actual tube expands the pin grips between the two halves of the socket so that everything becomes rock-solid.  This is the normal way they work.

 

[kevin gilmore]

pin 1 on the top side of the board is definitely missing and will have to be jumpered

 

[pureangus62]

I think you lifted most of your pads. This was probably done by having the iron touching the pad for too long or having too hot an iron (if its adjustable).
 
If you are planning to jumper from the socket pins to the traces on the PCB, be very careful. I'd imagine a short in the area would leave the amp unusable. Also, it doesn't take much to scrape the coating off of the traces so be patient and take your time.

 

[tomb]

  pin 1 on the top side of the board is definitely missing and will have to be jumpered

 
Well, now that you sharp-eyed experts are discouraging, maybe I should mention that the opamp and one of the capacitors next to it looks burned through, too.

 
You are definitely right about pin 1 - it looks like it took half the trace with it, too.

 

[pureangus62]

   
Well, now that you sharp-eyed experts are discouraging, maybe I should mention that the opamp and one of the capacitors next to it looks burned through, too.

 
You are definitely right about pin 1 - it looks like it took half the trace with it, too.

 
Wow youre right. At first glance I thought that was flux residue or something. Im guessing that cap got grazed by part of the soldering iron

 

[Starburp701]

Well, now that you sharp-eyed experts are discouraging, maybe I should mention that the opamp and one of the capacitors next to it looks burned through, too.

You are definitely right about pin 1 - it looks like it took half the trace with it, too.

Oh, NO NO NO!! That's actually some black goo stuff that was used on the underside of the board to stack the other PCB. I noticed it on the OP275 first and it cleaned off really well... just peeled off. Not sure how it got there but it was def there before I bought the thing.

 

[Starburp701]

Okay, so I just soldered it in. I don't think it looks too bad. It's not as level as I thought it was going to be which sucks because the tube is going to be halfway in the chassis.

[/IMG]

I bought a random multimeter off amazon. I've never used it and not quite sure how. Im just gonna wait for a little guidance before I plug her in.

 

[Starburp701]

I think it could definitely be worse.

 

[Starburp701]

Good news... my tube is firing up!!

While I was at it I attempted to swap out the atock pot with an Alps Blue 10k... the blue light that usually flicks on after 5 seconds isn't coming on and im not getting sound. I think im just confused as to where the silver wire (that leads to the hp jack) goes on the back of the pot.