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Comment by pvinis | Hacker News Reader

Genuine question. Aren't most mics now USB anyway? At least any mic that is better that a 5 euro one?

There are entry level mics that are USB, but professional mics have XLR outs with a hot, cold, and ground out, i.e. balanced output. You then need some sort of an audio interface like a Scarlet 2i2 to convert and connect it to your computer. An interface can also provide things like phantom power which condensers (a type of mic) require.

Generally speaking sound cards for regular computers aren't very good, so I'd bet the pi's is probably close to non-existent. You'd want some sort of DAC/ADC anyway. For listening purposes I've used a Fiio E9(or 7?) dac, and now I use a schiit stack.

Most professional mics have XLR connectors. Condenser mics require phantom power as well (unless they are battery-powered) which a "normal" 3.5mm audio jack will not provide.

The poster can't possibly expect the RPi people to include an XLR input.

Agreed, I'm not sure what they want out of the rpi.

If it's only 1-2 (xlr) mics, I would use a Scarlet 2i2 audio interface if possible and connect via its usb out. Although I have no idea how well it works with raspbian / ARM operating systems. There may be another type of interface that works with the rpi.

Either way, this is rather niche and goes beyond the rpi is intended for. You can still achieve rather good sound on a budget with a usb microphone depending on the room setup, etc.

It's strange how since the Raspberry Pi is so capable now, people expect them to build in all kinds of professional features into a $35 educational computer (PXE boot, pro audio, etc.).

The Pi can network boot.

I think maybe the 4 dropped that feature or maybe they're adding it via firmware? I remember reading a story about a company hosting dedicated servers on Raspberry Pis and complaining how they couldn't network boot on the 4, which is just ridiculous.

It's not implemented at launch, but the boot loader code is no longer in ROM so can be changed, and they said they will bring network booting later this year.

https://www.raspberrypi.org/documentation/hardware/raspberry...

"Support for these additional bootmodes will be added in the future via optional bootloader updates. The current schedule is to release PXE boot first, then USB boot."

They released the 4 without netboot and USB boot. The rough timeline that I read regarding firmware updates indicates that network boot will be done in a couple of weeks and USB boot will be done in about six weeks.

PC 3.5 millimeter jacks do have a DC bias similar to phantom power, it’s just lower.

Not exactly. XLR mics, as mentioned above, have a balanced output which needs to be connected to a balanced input. The 3.5mm "plug-in power" mics are unbalanced.

Phantom power is usually 48V, sometimes 12V, and rarely some voltage in between.

Apparently there's a HAT for that...

https://www.hifiberry.com/shop/boards/hifiberry-dac-pro-xlr/

Most profesionnal microphone uses XLR connectors. USB microphones alreaded proces the raw signal somewhat (at least an analog to digital conversion step); usually you want dedicated hardware for that.

There are good quality USB soundcards to be had these days - most with connectors for external mics. This allows you to control the a/d step completely.

I use and recommend the Samsun Q2U, a SM58-clone which has both XLR and USB. (There's an AudioTechnica version of it too I believe.)

Most microphones used in audio production are passive with usually an XLR out, so you either need an active amplifier on the device or a usb audio interface in between

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