I have a Steinberg UR-22 with two inputs, Input 1 and Input 2. There is a switch on the back panel that can turn on phantom power for both inputs. Unfortunately it’s not possible to turn on phantom power for just one input.
I connected an XLR cable to Input 2 and it gives phantom power between pins 1-3 and 1-2, and of course nothing between 2-3. There is another switch (button) on the front panel that can turn on high-impedance for Input 2. The phantom power stays on Input 2 if I turn on high-impedance. I don’t really understand why. Is there even any high-impedance input device that requires phantom power?
So I would like to record from the microphone while playing on the guitar. I would like to know is if I can plug in my unbalanced, high-impedance guitar and my condenser microphone together by turning on phantom power.
Theoretically this should work using a standard TS cable for the guitar, the PhP should not appear across the tip and sleeve. I have heard however, esp. with regard to the UR22 that this can result in a hum or buzzing in one of the channels. It probably depends on the specific mic, guitar, cable quality etc. so best to try it and see.
Meanwhile I measured the phantom power connecting a 6.3 balanced jack to Input 2. Balanced to be able to measure all the pins. The other end of the balanced cable was XLR. No phantom power I could measure between any pins. So it seems that UR-22 doesn’t give phantom power to non-XLR connectors. I’ll measure Input 1 as well.
Fine, I have measured Input 1 as well. UR-22 has hybrid input connectors which means you can plug either an XLR or a 6.3 mm jack into them. No phantom power is present on any of the jack inputs, regardless of the state of the phantom power switch or the high-impedance button. So it is safe to use a guitar while phantom power is on if you connect it via jack.
What still bugs me a little bit is that it has its phantom power switch is on the back panel while the user manual tells me to keep it off when I don’t use an input device that requires it. It’s pretty inconvenient to reach at the back of the unit and then find the switch. On the front panel there would have been enough room to place it there, for example at the bottom-right corner where there is a steinberg logo now. I don’t see the logic why the phantom switch had to go to the back. Although this is “fixed” on UR-44, not everyone needs four inputs who would need a convenient phantom power switch.
