Edirol UA-4fx USB Audio/MIDI IO device

Advanced Driver toggle switch

On the left side of the UA-4FX, there is an on/off switch called "Advanced Driver", which controls the USB mode of the device.

In advanced mode (Advanced Driver switch ON), the UA-4FX can record or play sound in native 24 bits, in either 44.100 Hz, 48.000 Hz or 96.000 Hz sample rates. You can choose sample rates using a switch next to the Advanced Driver switch. At 96 Khz, the device is either capture or playback only. MIDI is enabled. Advanced mode support was added in 2.6.28, see below. In normal mode (Advanced Driver switch OFF), the UA-4FX is fully USB sound compliant. It records at the rate of 44.100 Hz, in 16 bits, and is full-duplex. MIDI is disabled.

Sample rates switch

On the left side of the UA-4FX, there is a switch button called "SAMPLE RATE". The switch has four values: 44.1 kHz, 48 kHz, 96 kHz RECORD, and 96 kHz PLAY:

With Advanced mode OFF, the device will always record/play natively at the rate of 44.1 kHz using 16 bits.
With Advanced mode ON, the device will be able to record using 24 bits. Choose the sample rate using the SAMPLE RATE switch:
- 44.1 kHz: play and record at the same time,
- 48 kHz: play and record at the same time,
- 96 kHz: play OR record, but not both.

Cold/Hot reboot

Whenever you switch from Advanced ON to Advanced OFF, change sample rates, or change from 96 kHz RECORD to 96 kHz PLAY, you will either need to:

cold reboot: Unplug the USB cord, plug it again. The hotplug mechanism will remove all snd modules and will reload them. Be warned : frequent plug/unplug may harm the device physical contacts.
shutdown/reboot your computer: it is the recommended way, as it will not harm your device (or the USB cord). Your computer might not turn off the USB power unless you shut down completely. A good place to switch the Advance button is during the grub menu, if you are using grub, and if that fails, shut the computer off completely to switch the Advance button.