Other Parts Discussed in Thread: TL072
Hello to everybody,
New on this forum, i hope that someone will be able to help me.
So, I meet en issue with that AOP (OPA2134) that i don't understand... it is running hot. I mean, really hot, even on idle state.
Here is the context; i have designed a preamp which uses TL072 AOPs and it works very fine. But i wanted to reduce nose, so I have replaced these TL072 by OPA2134,
The noise is now perfect but the OPAs become hot..slowly buiti surely. In about 5 minutes, they become intouchable with fingers !
Here are the mods i have tried, unsuccessfuly:
- adding of 100nF caps between V+ and GND and between V- and GND for all AOPs, the nearest of the pins
- i thought the problem was about the Power supply (a symmetrical one), so i changed it from linear architecture to Switching architecture, with the good current ouput capability of course
- i have not noticed any oscillation around these AOPs
- I have checked if there was coupling capacitors everywhere between the stages
- the inputs "+" of the AOPs are linked to the GND (that is to says the middle supply because the AOPs are supplied with +/-15 V) with resistors
And nothing works, i mean the sound is very good, professionnal audio, but the AOPs are still running hots...
But not all of them, some are really hot, others are middle hot...
And with TL072 all is ok, nothing's hot.
Does someone have already had that kind of problem?
Thanks for your help !!!
Stef