Problem using a pair of AD8066 at I/V stage

[Noak]

hi all,

I was working on a DIY CD player based on PCM1794. The differential signals are input to a pair of dual opamps at I/V, then going to the buffer stage via a single opamp at each channel. The supply voltage is +/- 9V. The i/V stage uses a 2200pf cap and 820ohm resistor for each signal path. The power supply pins are decoupled by 100nf caps.

I have no problems using AD8620 and AD8599 or a pair of op627 at the I/V stage but once I place in a pair of AD8066, there will be no sound at the output.

However, if I were to place only one AD8066 at either channel, I will have output signal. If I were to place one AD8066 while I use any other opamps at the other channel, I will have output signal as well. However, it will never work with a pair of AD8066. I have tried 4 known working AD8066 but to no avail.

What am I missing here?

 

[Mooly]

Circuit

 

[Extreme_Boky]

I use 8066 almost exclusively for I to V and haven't had any problems... without a diagram I suggest you check the input (current in) pins for any oscillations.... but definitely try to obtain and show us a circuit diagram.
Boky

 

[Noak]

Will definitely post the circuit once I've got it drawn out.

 

[Noak]

I have attached the schematic.

 

[analog_sa]

My guess is oscillations due to insufficient PS decoupling. Try placing elecrtolytic caps close to the PS pins of each IC and play with bypass values.

 

[Noak]

hi analog_sa,

Thanks for the prompt advice! I will proceed to try that out!