Lowpass filter design

[01795584233]

I have designed a low pass butterworth flter(4th order) for a cut off freq. of 10Hz. Taking care that the gain of the filter should be -80db/decade.I am using a JFET opamp TL064. The problem is, I get the gain in postive and the signal isn't attenuated.I have designed also the passive components according to the specifications. Can any one give suggestions on this..
Thanks in advance
Senthil

 

[AlanTheWoo]

can you upload your design to a server? i would suggest that if you're trying to make a filter with -80dB/dec, you should consider a passive filter instead of an active. without evaluating your design, i would also suggest confirming that the +/- terminals of the op-amp are wired according to the proper schematic.

AlanTheWoo

 

[Lewish]

What are the voltages on pins 4 and 8 of the opamp?

What is the Vpp of the input signal?

 

[01795584233]

Hi lewish,
The 4th pin is the VCC of +12V and the 8th pin is the output of the opamp.4th order butterworth filter

 

[Lewish]

Oops, between the ears I had a misfire. I meant to ask the voltages on pins 4 and 11.
Please advise on those.