The other day I've got a Chinese clone of HiFiBerry, a PiFi DAC+ v2.0:

PiFi shield

Here are the steps to configure it with Volumio.

First, you need to install Volumio 2 (2.129 at the moment of writing).

Volumio UI

You need to configure it to e.g. connect to the network, index songs.

Note: Back up your config.txt (and wpa_supplicant.conf)

Once you've got it up and running, select the Playback menu:

Volumio UI

... and select the Hifibetty DAC Plus for the Output Device and *DAC Model. Make sure you enable I2S DAC:

Volumio UI

For the options, I've left the defaults on:

Volumio UI

Same for the playback options:

Volumio UI

For the Volume Options, I've selected a Hardware mixer type with a Digital mixer control name:

Volumio UI

Once you save the configuration, you'll be asked to reboot. Do so. This will create a custom config.txt with something like:

initramfs volumio.initrd
gpu_mem=16
max_usb_current=1
disable_splash=1
dtparam=audio=on
dtparam=i2c_arm=on
dtoverlay=hifiberry-dacplus
dtoverlay=lirc-rpi:gpio_in_pin=26

Note: Saving the info will create a clean config.txt. All your customisations will be gone. Therefore, before restarting, edit your config.txt with your customisations (e.g. network or LCD).

HTH,