[DingoSmuggler]

Quote:

I'm sorry about that tube socket.  The quality control is not so good sometimes.  They're wrapped in that wax paper stuff when I get them from China and I don't have time to check them all.  Every once in a great while, the ceramic gets molded badly and the tube pin holes get covered up, as you stated.  I would recommend the tip of a sharp knife such as an X-acto.  Ream the hole out by twirling the tip of the knife in the hole.  You have to be careful, though, if it's bad enough you could crack the entire top half of the socket.  If it's unsuitable, let me know and I'll send you another.
 
 

Cheers for the offer, but i think it will be ok. I can still plug a tube in, so I'll just leave as is.
 

 

[DingoSmuggler]

 
Got everything soldered up, cleaned, pre turn on checks....
....switch her on and nice glow from tubes, no glow from LEDs
checked B+ and no voltage. turn it off and waited 20 minutes
came back, measured a few things, the high volt secondary of the power transformer is reading about a meg ohm resistance  
 
i'll desolder it and see if reflowing the terminations on the lead-outs fixes things, but i fear the worst for this tranny
 

 

[jdkJake]

 
Quote:

 
Got everything soldered up, cleaned, pre turn on checks....
....switch her on and nice glow from tubes, no glow from LEDs
checked B+ and no voltage. turn it off and waited 20 minutes
came back, measured a few things, the high volt secondary of the power transformer is reading about a meg ohm resistance  
 
i'll desolder it and see if reflowing the terminations on the lead-outs fixes things, but i fear the worst for this tranny
 

I would be surprised if the tranny itself is damaged. They are pretty robust.
 
Measure the resistance between B+ and ground. The ground pad next to B+ is nice and handy. I would be surprised if you did not have a short.
 
Any pics? 
 
 

 

[DingoSmuggler]

Quote:

 

I would be surprised if the tranny itself is damaged. They are pretty robust.
 
Measure the resistance between B+ and ground. The ground pad next to B+ is nice and handy. I would be surprised if you did not have a short.
 
Any pics? 
 
 

B+ to ground is 238k ohms, which seems to be right to me.
 
The secondary winding of the tranny at my guess should easily be under 1k ohm, 1meg ohm is definitely not right
 
i can't get pics tonight, will have to be tomorrow for those
 
 
i managed to reflow the lead-out connections for the high volt secondaries on the transformer without desoldering it, but this didn't help things. 
 
 

 

[jdkJake]

Quote:

B+ to ground is 238k ohms, which seems to be right to me.
 
The secondary winding of the tranny at my guess should easily be under 1k ohm, 1meg ohm is definitely not right

True. I am measuring ~256 ohm across the high voltage secondary.
 
While hard to verify once solder into the board, you should be able to visually verify the wires coming out of the transformer and wrapping onto the pins.

 

[dsavitsk]

I bet that there is a cold solder joint on the transformer itself. The wire they use to wind transformers is enamel covered, and if the manufacturer did not do a good enough job stripping the enamel, then the wire could be "soldered" to the pins, but not actually connected. If this is indeed what happened, repairing it will be a pain, but much less of a pain than trying to desolder the whole transformer -- ask me how I know that

So, take a look at the pins and see how good that solder connection is.

 

[DingoSmuggler]

Quote:

I bet that there is a cold solder joint on the transformer itself. The wire they use to wind transformers is enamel covered, and if the manufacturer did not do a good enough job stripping the enamel, then the wire could be "soldered" to the pins, but not actually connected. If this is indeed what happened, repairing it will be a pain, but much less of a pain than trying to desolder the whole transformer -- ask me how I know that

So, take a look at the pins and see how good that solder connection is.
 

I'm not going to ask 

 
Yes this was one of my suspicions, and what i meant by "reflowing the lead-out wires" - but of all the joins on the transformer, these ones are the most obscured by other components, so I couldn't really see how bad the factory solder job was, or how much my reflowing of the joins was helping...
 
I had made an attempt at desoldering the transformer, and was left humbled. I think i will have better success removing the choke and C1 to give me some room to play, and try to fix the transformer in situ as you suggest.
 

 

[tomb]

I was waiting for Dsavitsk to respond - he is the authority, including/especially about the transformers.  It sounds like he has a good suggestion and we appreciate it if you are willing to work with it.  This is especially true because you're international and shipping won't be cheap or quick.  So, many thanks if you can try what Dsavitsk suggests.  However, don't keep trying long enough to get frustrated or even damage the transformer.  Of course, I will send you another one if it comes to that, but we'll need yours back to return to Edcor (I'll pay for shipping).

 

[dsavitsk]

I had made an attempt at desoldering the transformer, and was left humbled.

The trick seem to be to add a ton of flux the joint and add some to your desoldering braid, then suck out the solder from each pin in turn. It is also a good idea to do the ones connected to traces first as then the excess weight will be on the pins that don't matter so much.

Also, I find it helpful to use a flat heat screw driver to pop each pin once all the solder that can be is removed.

but we'll need yours back to return to Edcor (I'll pay for shipping).

Bah -- don't bother. I am sure Edcor will replace it, and if not, I'd rather eat the cost than force you to ship a bad part half way around the world.

 

[DingoSmuggler]

OK, I've got a plan of action now.
Given the time zone differences, should hopefully provide an update while you're all happily sleeping 

 

[liamstrain]

Quote:

Bah -- don't bother. I am sure Edcor will replace it, and if not, I'd rather eat the cost than force you to ship a bad part half way around the world.

I just needed to comment here. Classy. Seriously. Big points to all of you for being willing to get this right for him. 
 

 

[glenda]

You could try gently sanding the enameled wire with a file then solder a jumper down to the pin.

 

[DingoSmuggler]

So i removed C1 and the choke which gave me room to work, so i decided to get desoldering braid in there so i could se how much winding wire was there. There was about 2 or 3 turns of winding wire wrapped on each post and it was definitely well tinned. Soldered them back up and it still reads open circuit.
 

 

[tomb]

I will do my best to get a transformer in the mail to you tomorrow.  I'm pretty sure I know who you are, but PM me your address, just in case.

 
EDIT: Shipped yesterday.

 

[looser101]

Don't know what it is about my build that may be different, but I can't detect any hum.  Had it out to a mini meet last night and no one could hear any either.  Sounds great with Grados, and can drive a K340 even though it could use a bit more gain (for quiet recordings).  Thanks to Tom and Doug for making it easy to build, by providing us with a kit.