Do I need a phantom power box?

I just got a Roland Juno-DS88 keyboard which has a a built-in interface that can be used with a dynamic microphone. Should I get a phantom power box and plug in my condenser (since condensers need phantom power) or should I just buy a separate interface for the condenser?

A dynamic microphone is just a coil of wire conveniently close to a magnet. Yell at it and it makes a sound signal, so it doesn’t need anything. A condenser microphone has electronics in there and it has to get power from somewhere. Many condensers have batteries. Field news gathering shotguns work this way and the ones that don’t typically demand phantom power.

It’s called Phantom Power because the power goes from the mixer or phantom generator up to the microphone while the sound goes the other way on the same wires without bumping into each other.

You should group all your music onto one “thing” because Audacity will only recognize one device at a time.

This is me looking at the keyboard.


That’s a red flag.

The Mic-In is barely mentioned at all in the product info and the connector seems to be 1/4" and not an XLR. If the keyboard is expecting a dynamic microphone wired as a rock band microphone this may not work so well with a condenser. The IN and the OUT of phantom generators tends to both be XLR. It’s part of the phantom electrical dance.

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And that brings you up to trying to connect the keyboard and microphone as two different devices. I don’t think you can do that. Other elves will correct me.

I connect my condenser microphones with a Behringer UM2. It boosts the volume, supplies phantom power and connects it to the computer. I have sound mixers which will do that, too.

But not connect two different USB devices at once.


Windows or Mac? I think my Mac has the ability to create a Composite Device and mix two USB connections. But that’s not a Get Out Of Jail Card. Sound sync between the two will drift off.

You never said whether you were going to perform live or record the performances.


Although the Juno-DS88 manual does mention “USB audio” once, it is unnervingly vague about it. Have you tested recording the Juno via USB to see if it works?

I would expect that even if the built-in USB allows you to record the microphone, it will at most allow you to record a mix of microphone and keyboard, not on separate channels. If this is the case, then that is quite restrictive because you will have to get the keyboard / vocal mix exactly right before you start recording, with no chance to adjust the level of (or Eq) the vocals later.

I suspect that the main reason that Roland added the mic input was to provide stage performers the convenience of being able to use a keyboard “combo” for keyboard and mic.

The Juno manual does say that the keyboard does NOT support condenser mics.

How are you intending to use the mic and keyboard? Choice of equipment depends on what you want to do with it.

manual does mention “USB audio” once

It also says MIDI support, but only has one USB connection. How do they do that?

There are ways to force your microphone to work. Use a third party Phantom Adapter and then on to a passive direct box for the conversion to your Mic-In.

That’s not recommended because of the possibility of sound damage through multiple adapters.