Help replace JRC2068DD with LM4562 on CD Player

[costa23]

Please Help .....
I just trying to modified my onkyo dx 7711 cd player, I've minor changed :

- All diode with Telefunken SF 4007
- put socket for opamp
- Opamp JRC2068DD with LM4562
- JRC2068DD supply cap with Nichicon Muse BP

I think JRC2068DD is as balanced to single ended converter, or may be as I/V Converter (I'm confused).
'cause i'm a newbie n my soldering iron tip was broken some op amp pcb layout broken, and i did some jumper.
After replacing with LM 4562, the results is more open and transparent sound.
But the sound is like cracking especially in my tweeter, (the female voice and piano sounds weird)
I measure the LM4562 DC voltage (both left n right op amp) on pin :
pin 1 : 0.01 volt
pin 2 : 1.56 volt
pin 3 : 1.56 volt
pin 4 : - 15 volt
pin 5 : 1.56 volt
pin 6 : 1.8 volt
pin 7 : - 15 volt
pin 8 : 15 volt

are there DC offset ???

Please help me, I'm newbie and know nothing about op amp.
What's wrong with my cd player ?
Thanks

[abraxalito]

Originally Posted by costa23

...

pin 5 : 1.56 volt
pin 6 : 1.8 volt
pin 7 : - 15 volt

...
are there DC offset ???

There's a problem with this channel. Pin 5 is the +ve input, pin 6 is -ve. The opamp is always trying to make those two inputs the same voltage. There's feedback from the output on pin 7 to pin 6. The reason pin 7 is such a low voltage is the opamp is trying to make pin 6 more negative - unfortunately it doesn't have enough supply voltage to achieve it. So instead its done the best it can, which is the -15V supply. So I suggest you look for ways that pin 6 voltage has become too high - it should be 1.56 volts. Maybe something is feeding current into pin6 which shouldn't be.

[costa23]

okay, i'll try to trace the pin 6 and pin 7 .

Thanks a lot for ur suggestion

[costa23]

thank for ur suggestion, now i've solved that problem.

Thanks a lot