Hallo,

the calculation might look good on the paper but did you measure the real power and the current the amp draws from the transformer ? This is a MUST to make sure that there is no problem with the circuit or the layout and that the amp does not more current than exacted.

Best regards, Dirk

I measured all voltages and bias current, all measures were in the correct range that the original schematic shows (+-5%).
I don't have a oscilloscopic and I can't measure the real clean power before clipping of the amp.
The transformer never get very hot, only when the short happened it get very toasty.
The output tubes are in good condition and nothing else in the circuit looks damage or wrong.

SPAIN?

take care
stay safe

Jochen

We are throught a big drama, thanks for the support.
I think I report your comment by error when I was trying to quote your reply, sorry.

I measured all voltages and bias current, all measures were in the correct range that the original schematic shows (+-5%).
I don't have a oscilloscopic and I can't measure the real clean power before clipping of the amp.

So you do not know if there was any kind of oscillation or the real power consume of the transformer.
Such issues happen from time to time but in most cases the user/customers refuses to take a critical look to his work. Of course a transformer can fail but if it breaks after it has been in use for a while then the eye-catching. The probability of incorrect use is greater the longer the transformer was in use. This is my experience.

Best regards, Dirk

Thanks Kirk,
I thought that the conjuntive filter of the desing filter out all the high frequency and non audible oscillation in that particular circuit, that together with all corrects voltages, no power losses, sag or overheating, ... All this made me think All was running fine. I didn´t can measure any sub-bass oscillation, I don´t feel any lacks in perfomance in this department, but maybe it was the problem.
The transformer only gets hot when it lose power and shorted showing a low output voltage.

Best Regards!

PD. This forums is exciting, a lot of useful info but I am fighting with german google translator extension, hehehe.

My Name is Dirk. I have nothing to do with Star Track  :devil:

Please keep in mind that non audible oscillation must NOT be present all the time !

Best regards, Dirk

Oh, Sorry Dirk for the error. Strak Trek rules, hehehe.
The new TT50Va is different of the old one, the diameter are 74mm in the new one (80mm in the old one) and the height is 34mm (40mm in the old one)
The green wax cover fully  the hole in the new one Vs the old one only cover half of the height.
Maybe this changes could get the transformer more sensitive to the stress?
Do your think the new TT50VA conventional transformer is more robust?

Regards, Daniel.

And a few pics of the clone:

Here:

Maybe this changes could get the transformer more sensitive to the stress?

No, it is just a different manufacturer. You should stop chasing cars.

Best regards, Dirk

Hehehe, ok, the seclusion at home give a lot of time to turn thing around.


Best Regards, Daniel.

Hehehe, ok, the seclusion at home give a lot of time to turn thing around.


Best Regards, Daniel.

Hi Daniel,
you might check your Leaddress - your amp might oscillate.
If you can gain access to an oscilloscope  - i would recommend to use it...

You might also get a simple "Energy Monitor" which can measure effective power consumption... These are cheap. If the amp draws excessive power from the mains - you will see it there...

regards
Jochen

It´s difficult now get any electronic equipment, only online shopping.

What part of  the circuit do you think could oscillate?

Best Regards,

It´s difficult now get any electronic equipment, only online shopping.

What part of  the circuit do you think could oscillate?

Best Regards,

at least here - you won't find such an energy monitor plug in local shopping...
Online - they are are available for >20€

HHmmh - where to look at?

At first glance - sorry - please don't consider me rude - everywehre...

regards
Jochen

The truth is never harsh, hehehe. I am going to find a monitor or a oscilloscopic and check de layout.

Thanks!


Regards!