1176 Gyraf: Vu Meter Null position troubles

[Fandangoita]

Hello. I have successfully built several 1176 Gyraf/Mnats version. For the first time I get this trouble with the vu meter: When I switch the unit on, after several hours been off, the vu meter needle doesn't respect the zero null previously setted and it jumps few db over. The gain reduction behave is the same, only starting from a different higher point. Keeping the unit on, the needle slow by slow goes down back to the right position. Otherwise, if I apply on the Null trimmer setting the position to 0db again, after few hours I find the needle few db's below zero. I have already changed the get and the IC in the vu meter section but the problem still persists. Any idea? Thanks a lot. (I am getting mad..)

 

[jensenmann]

It´s not a bug, it´s a feature  ;D
Don´t worry too much, most 1176 I´ve seen behave like that more or less.

 

[Fandangoita]

I agree, but this time it seems to be  too much..

 

[Stagefright13]

Trust me that is completey normal for an 1176. Needs to  be on 2 to 3  hours before calibration.

John

 

[Gustav]

I agree, but this time it seems to be  too much..

If you think its more than usual, you could try swapping the FET!?

Gustav