Yes- if pin 3 is not tied to pin 1, while the RCA is in use, the amplifier will buzz whether the preamp is on or not, and whether its plugged into the wall or not.
Also, FWIW it is not uncommon for a preamp to buzz if it is not powered up. The reason is that the output impedance is usually much higher and can act like an antenna.
If the Aesthetix is really balanced, you should not have any troubles making this work.
Also, FWIW it is not uncommon for a preamp to buzz if it is not powered up. The reason is that the output impedance is usually much higher and can act like an antenna.
If the Aesthetix is really balanced, you should not have any troubles making this work.