Boiling power transformer

edenfield99

I’ve had a Louis Electric Tremoverb amp for a few months. I’ve not used it a massive amount, probably less than 25 hours in total, and worked fine until rehearsal on Friday. The sound dropped off quickly while playing and smoke started coming out of the back. Turned it off, sulked a bit and brought it home. I’ve had the back off this afternoon and powered it up on standby and it sounds like the power transformer is boiling...it’s getting very warm very quickly and I don’t really want to leave it on very long like that. I can’t see anything obviously wrong (loose wires or damage). Can anyone help identify what this might be? I will return it to Coda as it should still be under warranty but that’ll be a pain in the arse as I haven’t got the box anymore (and it’s heavy) but if anyone knows anything that it might be worth checking as a way of fixing it that would be appreciated.

gringopig

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ICBM

Remove all the large valves - power valves and rectifier(s) if it has them - but *not* the preamp valves. Power it up. If the transformer still gets hot it needs to go back, since it's most likely that the transformer is faulty.

ecc83

Could be a short on a secondary winding but in any case, smoke indicates replacement is highly likely.

Do not worry about the box. Contact the supplier, it is THEIR responsibilty. Because it is heavy and expensive to ship they might ask you to take it to a local tech and they supply the parts.  Let us know what they say. I thought we had a consumer lawyer type on the forum?

Dave.

DJH83004

Looking at an image of the back of a Louis Electric Tremoverb, it does have a GZ34 rectifier valve, so you could just take that out, which would isolate the HT side and the 5v rectifier heater supply, but as already stated if the PT has been smoking, then it should be returned for a replacement transformer under the manufacturer's warranty.

prlgmnr

I kind of think "smoke is coming out of it" is a good time to stop home troubleshooting and take it to a tech.

edenfield99

Thanks everyone, I’m going to contact Coda tomorrow and see what they suggest. The large amount of alcohol I’ve consumed has made any further probing into an electric device inadvisable tonight. 

Fenderish

shorted rectifier tube is common with GZ34. What's less common is that the mains fuse didn't blow before the PT

It's either bad design or bad luck (if the rectifier tube shorted "strangely" enough to make the PT really hot but not enough to blow the fuse...)

If you saw smoke from the PT it's likely the PT is dead or soon to be, I wouldn't use it anymore...

oh and filter caps have a good chance to be dead too, sorry

Van_Hayden

If it sounds like a hissing boiling noise from the transformer send it back if it is under warranty. That and magic smoke is the death of a transformer. 

edenfield99

So a bit of a follow up on this...

The amp was returned to Coda. It was returned to their tech who reported the power transformer failed due to faulty valve. Now, 10 weeks after I returned it, the replacement transformer has still not been supplied by Louis Electric even after a number of attempts from Peach/their tech to get one. The tech is now suggesting getting one from the UK and using that.

What are your thoughts on this? My issue is that even though it is only the power transformer and should not affect the sound it is not an OEM part and could devalue the amp if I choose to sell it on. I bought the amp new in January and through no fault of my own I will no longer have a 100% original product (I can understand if the issue was just replacement tubes as that is normal but the power transformer shouldn't need changing).

I am just being fussy or should I demand replacement or refund? I've pretty much lost faith in Louis Electric as this is the second amp I've had issues with.

I would like to make 100% clear that Coda have been great through all this and I have absolutely nothing bad to say about them. Marc has kept in touch and let me know what is going on and when I have chased has got back to me straight away. The issue is with Louis Electric and very poor customer service. 

jpfamps

edenfield99 said:

So a bit of a follow up on this...

The amp was returned to Coda. It was returned to their tech who reported the power transformer failed due to faulty valve. Now, 10 weeks after I returned it, the replacement transformer has still not been supplied by Louis Electric even after a number of attempts from Peach/their tech to get one. The tech is now suggesting getting one from the UK and using that.

What are your thoughts on this? My issue is that even though it is only the power transformer and should not affect the sound it is not an OEM part and could devalue the amp if I choose to sell it on. I bought the amp new in January and through no fault of my own I will no longer have a 100% original product (I can understand if the issue was just replacement tubes as that is normal but the power transformer shouldn't need changing).

I am just being fussy or should I demand replacement or refund? I've pretty much lost faith in Louis Electric as this is the second amp I've had issues with.

I would like to make 100% clear that Coda have been great through all this and I have absolutely nothing bad to say about them. Marc has kept in touch and let me know what is going on and when I have chased has got back to me straight away. The issue is with Louis Electric and very poor customer service. 

This is the big problem with small builders selling kit overseas. 

Myself and a colleague often deal with these sort of issues and it can be a real pain getting original spares.

One US builder (whose work would pass NO safety standard) simply said use a Hammond off-the-shelf for a blown output transformer rather than try to supply a replacement. They paid us to do this, but that's hardly the point.

edenfield99

Just as an update it will be like-for-like so maybe I'm being a bit fussy!

Lebarque

edenfield99 said:

Just as an update it will be like-for-like so maybe I'm being a bit fussy!

I was going to say... Surely they just use one of the good transformer manufacturers, such as Heyboer or Mercury Magnetics anyway? A good amp tech should be able to get and install one and it will be as good as new.

Like you say, Coda provide top notch service and I would assume they're pretty naffed off at Louis Electric too. Not good. It's got to be said that it's not the first time I've heard reliability issues with them - even one in Coda I tried had something wrong with it! They do sound deliciously 'old' though.

edenfield99

Lebarque said:

edenfield99 said:

Just as an update it will be like-for-like so maybe I'm being a bit fussy!

I was going to say... Surely they just use one of the good transformer manufacturers, such as Heyboer or Mercury Magnetics anyway? A good amp tech should be able to get and install one and it will be as good as new.

Like you say, Coda provide top notch service and I would assume they're pretty naffed off at Louis Electric too. Not good. It's got to be said that it's not the first time I've heard reliability issues with them - even one in Coda I tried had something wrong with it! They do sound deliciously 'old' though.

Ou're right, I have a Buster already and it sounds awesome...so did the Tremoverb while it worked.

RiftAmps

Every LE amp I've seen has had standard off-the-shelf Heyboers. Nothing wrong with that but getting a replacement shouldn't be difficult.

OP - happy to help in any way that I can

ecc83

In theory any transformer made to the same spec' should perfom equally well. In practice not always so.

One of my most common jobs was to evaluate transformers from various sources (you don't get all your eggs from one farmer!)

Most of the time the traffs were fine and delivered the right voltages/ratios but I well recall an OPT that lasted less than an hour on the torture rig in an HT-60.  Fortunately fuse(s) prevented any collateral damage.

It is not the OP's fault that the design was so poor that the transformer was not protected but it IS the retailer's responsibility to effect a proper repair or a full refund in a timely manner.

Dave.

Modulus_Amps

ecc83 said:

It is not the OP's fault that the design was so poor that the transformer was not protected but it IS the retailer's responsibility to effect a proper repair or a full refund in a timely manner.

Dave.

Who determines what a "proper repair" is?

To the OP, have you tried contacting LE yourself so you can get the story straight from the horses mouth?

2 months later and you don't have your amp back or any sign of when you will get it back, that is not acceptable really

merlin

Just saying.... I've bought two Louis Electric amps (a KR12 and a Columbia reverb) and both ended up going back to Coda. The KR12 motor-boated like crazy and the Columbia's main transformer burned out, filling my room with stinky black smoke. Coda were very good about it, accepted all shipping costs although they had to send to Louis in the States to get a new transformer and it took a long time. 

edenfield99

Cheers everyone. Peach have said if it’s not fixed by early next week I can have my money back or new items. Let’s see how it goes

Budwiser

At least you are spare parts if they send a replacement amp out..

Just a bit odd that the output tx should cook like that. 

ecc83

Modulus_Amps said:

ecc83 said:

It is not the OP's fault that the design was so poor that the transformer was not protected but it IS the retailer's responsibility to effect a proper repair or a full refund in a timely manner.

Dave.

Who determines what a "proper repair" is?

To the OP, have you tried contacting LE yourself so you can get the story straight from the horses mouth?

2 months later and you don't have your amp back or any sign of when you will get it back, that is not acceptable really

I would think a "proper" repair was fairly oviously a new transformer and a return of the amplifier to as new specification?

Dave.