Rattling Transformer Trace Elliot Commando 1001

[ByrdyBass]

Hey everyone,

New here to this forum and relatively new to amp repairs. I have a late 90s Trace Elliot 1001 100w head that works and sounds great except for one issue: there's a rattling sound that I can hear physically from inside the head, and also through the signal a little. This is really noticeable in my old apartment where there isn't a square foot of level flooring, so nothing is ever solidly sitting on the ground. I pulled it open and listened around while jiggling it slightly, and I believe the sound is coming from the transformer. Poked around and nothing appears to be loose at all. Cables are all solidly plugged in and the housing is mounted to the chassis really tightly. Not sure if this helps, but after putting it all back together and plugging it in again, I noticed sometimes the "rattling" speeds up. Like, if I jiggle it a little, it'll start slow and speed up until it eventually stops. Has anyone had a similar problem and figured out how to repair it without replacing the entire transformer? Can post pics of the inside if needed. Thanks!

 

[Wood and Wire]

That description sounds more like it would be related to the fan.

@agedhorse might be able to point you in the right direction for that era Trace Elliot, as well as caution you about some of the dangers.

 

[agedhorse]

That doesn't sound like a transformer issue at all.

 

[ByrdyBass]

It's perplexing for sure. This unit doesn't have a fan so unfortunately it can't be that. Everything inside seems very tight; nothing seems loose. The only thing I can hear moving at all when I have it open seems to be coming from inside the transformer housing. That's really all I know. I'll poke around a little more to triple check. Also unfortunate I think the housing is riveted to the chassis so I can't pull it and make sure that's where the sound is coming from...

 

[agedhorse]

It’s possible that the transformer was incorrectly manufactured and the VPI treatment was missed or done incorrectly. Not common but possible. There is no practical fix for this defect.

 

[ByrdyBass]

Hey guys. I think I figured out what's wrong. The transformer is not securely attached to the housing. I had never looked closely, but the two sides of the housing/mount, are being held to each other with zipties, and I can move the transformer a little bit back and forth, up and down inside the mounts. Also looks like there are some holes in the corners of the transformer that line up with holes in the mounts, with nothing in them. It's a little hard to get great pictures but I attached a few. Anyone have any ideas how all this is supposed to all be attached and secured? Any help is appreciated.

 

[ByrdyBass]

*Update: I saw a picture of a similar transformer from a Commando 12 and it looks like there might need to be a screw/bolt in the center hole, just under the lip of the bracket. Perhaps there should be one in the bottom center hole as well. Not sure what size screw/bolt though, and I don't know if I should find one that fits pretty snug or that just fits through and tightens the brackets to each other. Attached picture from the other amp and a clearer picture of mine. Thanks for any info!

 

[agedhorse]

There needs to be nylon shoulder washers on each side of the through bolts to avoid a magnetic short circuit and excessive lamination losses.

This may be why someone used zip ties instead.

 

[ByrdyBass]

Gotcha gotcha. Could I just add another ziptie to try and tighten it up so it doesn't move around? Like maybe through that hole where the screw should be? Or should I find a thin screw that doesn't touch the metal sheets of the transformer and some shoulder washers like you said to bolt it together?

 

[agedhorse]

Gotcha gotcha. Could I just add another ziptie to try and tighten it up so it doesn't move around? Like maybe through that hole where the screw should be? Or should I find a thin screw that doesn't touch the metal sheets of the transformer and some shoulder washers like you said to bolt it together?

Either way.

They aren't always necessary, it depends on a lot of materials and surface treatment variables, but it's best practice IMO.

Here is an example of the types of shoulder washers used on transformers:

 

[ByrdyBass]

Awesome!!! Thank you so much. I'm gonna try and find something like that. I really appreciate your help!!