warwickhunt

His thinking is that a component in the preamp is failing but only when its been on a while and gets properly warmed up. This fault then loads the TX (transformer) to the point that it overheats and damages one of the windings... seems reasonable. He's ordering a replacement transformer free of charge and he's going to run tests with the amp operating under load for extended periods. Fingers crossed.

When I have the amp back in my possession I'll try. <edit/update> I forwarded the image to the Tech that did the last transformer and it just so happens that he felt bad that his work had failed so he was looking at what he could do. He thought there should at least be a fuse on the HT side that would prevent the transformer cooking again (his transformer was rated 50% higher than the original). He is also going through every component to see what could have generated the fault, there wasn't any obvious cause and the amp operated as per normal when he replaced the original failed transformer).

Dang! Transformer is no longer in production but I was forwarded this...

In layman's terms can anything in the power section/output affect what happens before it? Could the output / power section be the cause of the transformer burn out?

I alluded to that earlier but don't have enough tech education to know how that works. Could it be that the power module is too big for the front end to power... am I simplifying the language?

2 x 500 watts 4 ohms / 1 x 1000 watts 8 ohms bridged... confusing labelling on the amp itself as it says 2/4 ohms but never run bridged and never below 4 ohms. Bear in mind the power section is class D and transformer is just for preamp valves.

I'm very much at the mercy of you guys as I've no tech knowledge. However, I'd suspect it is custom which would account for the stock replacement burning out. Briefly spoke to someone in the UK office and I've fired off those pics to them but I suspect it'll not have the important info that they'd need to identify it.

Blimey good find!

I did. I've had it repaired once... with a basic component and it worked flawlessly for <5 hours!

I agree or (and I don't have sufficient knowledge but applying common sense) something 'after' the preamp is causing some form of feedback/reverse issue. It could also be a case of the 17 year old transformer had failed but that the new one wasn't the correct spec.

No warning leading to either transformer failing (oddly it never exhibited any of the issues you had, when I used it). I'm waiting to get the amp back from the Tech but the faint whiff of smoke when it died on me leads me to assume it is the same issue... which means there is an underlying problem. I'd like to hope it is a fault and not a design oversight! The Tech who fitted the last transformer has offered a full refund but as he couldn't identify what lead to the failure he hasn't taken up the job of fitting the next transformer (if I can find a suitable one).

Guess what I found; I forgot I'd photographed it first time!

Sadly the original was fritzed (no visible 'useful' info) and the replacement wasn't up to the job so I'm back to square one.

Yes I believe the transformer is purely for the preamp / valves.

Lots of room around the offending article!

Thomas Eich went from Tech Sound to Tecamp to Eich! The guy who did the last work said that he was finding it hard to source the part as it was dual core (that might be my recall of what he said) and ended up getting it from Eastern Europe as a special order... for what good it did! Possibly the part wasn't genuinely compatible but without finding a competent repair guy who won't end up charging more than the amp is worth even after the repair, I want to get all the info I can to support the repair.

Mike at Zoot hasn't any info. No reply from Eich re. schematic... I'll give it another week though.

You've all clearly missed the biggest joke. It says Fender on the headstock... and we know Fender only make 4 string basses!

Fired off messages to Eich Amps and Mike... fingers crossed.

You'd think so but whatever the issue is, I'd rather not have to buy and have a 3rd transformer fitted and have it fry on me.

Cheers folks. Yes I tried Tecamp but they basically said it was old/obsolete and they didn't carry spares. I may well try Tecamp again and as @Bill Fitzmaurice has suggested try and get a schematic. Both repair guys said it was a straightforward job as the transformer was only for the 3 valve front end (class D output) but clearly not!

I owned this amp from new, sold it on BC and bought it back but sadly it looks like it is now destined for the bin as the transformer which delivers voltage to the valve front end has died for the 2nd time. The guy who first replaced the original transformer binned the dead unit (despite me asking him to keep it), when it died the 2nd time I used a different repair guy who had to source a unit from Eastern Europe... but this is fried. I hasten to add that the amp is my back up and when it died the 2nd time it had 5 hours use in the house! There is obviously a secondary issue here but neither tech found anything to indicate why they are dying. IF I can get a replacement I'll be sure that some form of diagnosis is followed up to see what, if any, is the issue It is a long shot but does anyone have one of these amps and can give me info from their original transformer or even better, does anyone have an amp that has other issues that they'd sell 'spares/repairs'?

C'mon... it's tongue firmly in cheek!