Hello,
how do I trim the input level,as I can`t find anything in the manual.
thx in advance
Peter
Welcome to AudioCircle, Jean Luc!
The manual describes a feature called "input trim" (at the bottom of this page:)
https://manuals.anthemav.com/mrx-avm/en/107#/Unfortunately, there is no real input trim, as Neo proved. A real input trim matches the signal voltage to the sensitivity of the input stage. In MRX, there is analog input stage which can handle 5V signal without distortion, but it's followed directly by ADC which can't handle hot signals. There is no analog attenuator between them.
The actual max input voltage above which causes digital "over" in the ADC is not specified by Anthem. 2V is the industry standard consumer level (RCA) signal, and Anthem wants to maximize the S/N ratio of the digital signal for their internal DSP so they set the full scale digital level closer to 2V.
This "input trim" is actually an output trim, which is adjusted separately by each input to match the output volume levels across all of the different inputs. This adjustment happens AFTER the analog signal is already converted to and a hot signal is already ruined.
There is no analog attenuation to prevent digital overs, so you have to limit the input voltage externally.
