[ferencvaros]

I have following problem - I completed my Pimeta (ad8610, ad8620, buf634RL x2, class A bias, STEPS 25,5V), until yesterday everything was fine, but today I turned my Pimeta on and heard only very quiet sound from background and some clicks .. So I measured it and realized, that TLE2426 does not split voltage at all - chips were powered with 25,5 volts, not 12,7 - so I resoldered it, turned it on, measured - everything was fine ... when I connected my headphones, again the same story - quiet sound from background and clicks - I measured TLE2426 again - and is burned again !!!

can somebody help me ?

 

[nikongod]

does your PSU (wallwart, steps, whatever) connect V- to earth ground? if so, you will bust the TLE_2426 every time you plug the amp into something that puts signal ground at earth ground.

consider yourself lucky, i once blew-up my soundcard that way. i would have sacrificed 100 TLE-2426 chips for that soundcard.

 

[Vadi]

I too have a problem I guess but I can't explain why:
I use an isolated power jack. The power supply is a linear wall wart and a Tread. The case is metal (and powdercoated). There is a plastic sheet under the amp-board
The amp worked until I rewired everything and changed the input jacks from isolated to unisolated. I also changed the position of the power-switch (before it was wired to the pads on the board).
AFAIK as long you use an isolated power jack, all other connectors are no problem?

When I switched on, voltages rose from normal to full PSU voltages at the DIP-8 sockets. The TLE was hot and fried I guess.

 

[tangent]

Quote:

Originally Posted by Vadi /img/forum/go_quote.gif The amp worked until I rewired everything and changed the input jacks from isolated to unisolated.

This ties the case to virtual ground, which means that any time you touch the case and give it a static shock, it goes right into the TLE's output. Not saying this is it for sure, but it would explain it.

 

[Vadi]

I tried again and when I connect the LED, the voltages double.

I use a 100K RLED now and it should be fine I think (it glows). Before there was a 7K5 RLED but that was too bright.