Empirical audio off ramp turbo I2S noise


Recently I install in my system a passive preamp that Im really happy with. The problem that I have is that if I use my off ramp turbo to convert usb to I2S that goes to my PT P3A, the preamp is picking up some noise from the off ramp, as soon as I unplug the I2S cable from the P3A noise disapears. If I use m2tech hiface usb to digital and the the P3A there is no noise at all.
Would like to know if other people found same issues or if someone have an explanation for that.
jorsan
Have you contacted Empirical Audio? Seems like they would be the most qualified to answer that question...
The stock P-3A is not properly terminated on the I2S input. This may be the reason. For most customers, I modded the P-3A to fix this, as well as a lot of other improvements. Did I mod your P-3A?

What kind of I2S cable are you using?

Steve N.
Empirical Audio
Yes Steve is the turbo mod. The problem is only there if I use a passive amp, not a regular one, in that case is dead silence. The I2S cable is the one that you provides me with the package.
You may have a ground-loop problem when you use the passive linestage. Make sure that the AC power for the P-3A, the Off-Ramp and the amp is all from the same AC circuit.

Steve N.
Empirical Audio
Thanks Steve. Yes, all are connected to the same circuit. One thing that maybe is usefull is that the noise is not volume dependant: doesnt matter if I rise or lower the volume the noise is always at the same level.
Yesterday I have tried in different circuits in my home and happnes the same in all of them.