What's going with this PT...help?

[ultisimo]

Hey guys,
I just finished my JTM45 build and I must say to Metro's credit, this amp sounds amazing! There's something a little odd looking about the laydown power transformer. There's a wire of some sort visible through one of the small round holes in the end cover. It's about the thickness of buss wire or solder. I contacted Fido and he said maybe a stray winding? That sounds scary. Yikes...defect? I haven't been able to get into it further with him, so I figured I'd open it up here to the experts.

He recommended to take the end cover off and see what's going on. Now, I don't really know if it will just pull off easily as I've never done anything like this before. It appears to be coated in some kind of wax or resin, much like a guitar pickup would be potted. So I don't want to disturb anything, or potentially ruin anything and be responsible for a dead tranny, before I understand what I should be doing. I'm a luthier by trade, so I love to mess with things and take them apart. That being said, I've learned the hard lesson of not going in blind!

Any advice from those in the know would be greatly appreciated. I've attached two pics below for your viewing pleasure. The first shows the "wire" running through the hole. The second is a close up of the side showing how the end cover is pushed up a bit from whatever is under there.

Thanks,
Rob

[arledgsc]

Could be anything from a winding out of position to a short piece of a clipped wire. If it were mine I would pull the top bell housing to see what is going on. If indeed it is a pinched winding or lead wire then I would certainly fix it and may mean tranny replacement. If the only thing between transformer working or not is a thin coating of enamel then it is a potential timebomb waiting to go off. I don't see how it could be a winding out of position unless the transformer was wound on a Monday after the company Christmas party. Also the connections are on the other side of the tranny so a wayward connector wire seems remote as well. But an inspection is relatively easy.

Better safe than sorry though Scott

[axeman]

Why wait for something to happen.

[ultisimo]

Ok, so that cover came off really easy. That feels silly. Here's what I found under the hood. The million dollar question...what is it?

[axeman]

Ground? May be.

[ultisimo]

That's what I thought at first. I just want to be 100% sure before I keep playing the amp. I'm still waiting on a reply from Metro cust svc, but any expert help here is welcomed!
Thanks,
Rob

[ultisimo]

Got an answer, and here it is just in case anyone ever runs across this, you won't have to worry about it...

From Metro cust svc:

Don't be concerned; that wire is called a core drain. It needs to be there, as its purpose is to drain off unwanted eddy currents.

Thanks everyone, now I'm off to shake the walls!

-Rob

[Flames1950]

I was pretty sure I'd seen the same thing on my first Metro JTM45.....but hell, that was four or five years ago now, and I didn't have any notes to tell me for sure........