Amplificateur de casque à 4 canaux, audio plus propre, 4 sorties TRS

The output of the amplifier is low. For example, when the line out on my mixer is run into the PHA40 it is too low to listen to on the headsets. I have a cheap little USB powered headphone amplifier that does a sufficient job on most audio. When I run the headphone output of that cheap amp into the line in on the PHA40 (to simulate using the PHA40 as a headphone line distributor), the audio level actually gets reduced! Is that as loud as the PHA40 gets or did I get a defective unit? BTW, before sending this question, I did some research and found that some 'low output' PHA40 actually had a 470 ohm isolation resistor instead of the 47ohm the circuit was designed to use. (the 470 markings on a PC board is 47 x 10^0 meaning 47 not 470 ohms) I used to do electronic repair, so I do understand the problem and how easy a mistake would be if you changed the people that populate the boards. I was tempted to repair mine, but I came to my senses. I will probably send these back to Amazon and get my $19 plus tax back.

You can take the Headphone-out jack of the mixer going into the PHA40

How big or how many watts can this item be plug with speakers

These are intended for headphones only

My mic and headphones are mini plugs (3.5mm). If I use adapters to connect with the 1/4 inch will that affect performance?

No it does not.