RME User Forum — Fireface 400 doesn't retain 48V "on" setting in standalone mode

Re: Fireface 400 doesn't retain 48V "on" setting in standalone mode

null@example.com (MC) — Tue, 09 Nov 2021 12:38:26 +0000

We checked. The Fireface 400 stores and loads the Phantom power state, with both driver 3.391 and 3.40.

Also with this state active, removing the FW cable does not switch off Phantom power.

Storing this state and switching the unit back on in stand-alone mode the Phantom power is turned on immediately.

It looks like your unit is faulty, maybe its internal memory fails somehow due to its age.

Re: Fireface 400 doesn't retain 48V "on" setting in standalone mode

null@example.com (MC) — Mon, 08 Nov 2021 03:02:43 +0000

Might be a driver problem, we'll check.

Fireface 400 doesn't retain 48V "on" setting in standalone mode

null@example.com (midwayfair) — Sun, 07 Nov 2021 23:09:58 +0000

Problem description:
I can activate 48V and adjust the settings for the gain etc. from Fireface Settings. When I click "Store" and disconnect from my computer, the gain settings are retained, but phantom power is turned off immediately.

It also appears that I have to have the phantom power *off* in the Fireface Settings dialog when I reconnect the device to the computer to be able to reactivate phantom power, but I haven't fully confirmed that this works every time. Sometimes I need to turn the device off and on to get it to turn phantom back on.

Some prior forum posts seem to indicate that this should work, and the manual doesn't mention a limitation, but I'm just trying to confirm whether this is expected behavior, as the unit works in all other ways the way it's supposed to.

I'm using a Mac on Big Sur; I have the September 2021 driver update and the most recent firmware (which appears to be 2012). I'm connecting through a Firewire > Thunderbolt converter and running off the power supply.

One note: This problem does not manifest on my Fireface UCX, which stores the phantom power setting via Total Mix.