You may ask Audiophonics directly why their amp config need 10VRMS of input with bypass.Sorry, but i have only very basic knowledge in technology. Here is a quote from audiophonics:
"The bypass mode is relevant in cases where the Purifi amplifier is used with a strong preamplifier supporting a load of 2 to 4kOhm with a voltage ~ 10V RMS."
Can someone please tell me the relevant output voltage of the Topping Pre90 - i cannot find it. Is it able "to support a load of 2 to 4kOhm with a voltage ~ 10V RMS"?
In case of questions: yes, i will use the Pre90 itogether with the DAC90SE as opposed to the DAC90SE alone.
2.2 and 4.4 kOhm is input impedance of ET400 in single ended and diff modes. Why Audiphonics use word "to" (continious) instead of "and" (discrete)?
It is all about output current of DAC/Pre outputs.