DAC line & headphone very loud (high gain / output)

Volumio Information

Volumio Version: 2.882
Hardware: pi 4
DAC: iquadio dac+ hat

Hi, thanks for making this awesome thing and the community around it. I searched the board and only found the a similar issue below. Not sure if this is related to the build or it’s always been this way - I can’t raise volume over 20 if I connect my DAC to power amp or head phone.

With a receiver things behave better, I can set volume moderately on the receiver and raise volume to 100 no problem. Things also behave as expected if I use the receiver as preamp and connect power amp to it’s preout.

Is it possible to connect the DAC directly to power amp or headphone, without a preamp? Is there volume scaling config setting I can alter so the DAC output isn’t so high? Do I need to change the scale from natural to linear? Would like to stay with hardware volume control.

TIA

It might be relevant to understand the maximum output of the DAC for a fully modulated signal. This is commonly around 2V rms on the RCA output and twice this if you have XLR balanced output. Then compare this with the input sensitivity of the power amplifier, if you’re using a power amp rather than integrated amp or receiver with a separate volume control.
If the power amp is very sensitive, say 200mV, then there is a risk of overdrive and perhaps a passive attenuator between the DAC output is a solution.

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