Audirvana shows 24 bit for Scarlett Solo, is this correct?

If we play 16bit/44.1kHz FLAC files with a “Focusrite Scarlett Solo USB” Audirvana shows “24/44.1kHz Stereo Int” in the bottom right corner.

This makes me a little bit unsure.

Will this say, that 24 bit are sent to the Focusrite DAC or what does the “24” mean?

Under Linux it is not possible to send 24 bit towards the Focusrite (format not supported), we must send 32 bit. Ok, this may be an error in the Linux Sound system. But also the lines of the Audirvana debug output (24 little endian Signed Integer aligned low in 32bit 44.1kHz) make me suspect that 32bit are sent to the DAC.

Does anyone have an explanation?

This is the log:

Audirvana Mac Version 3.5.34 (3564)
macOS 10.15.4 with 16384MB RAM

Registered to ***********

SIGNAL PROCESSING:

Polarity Inversion:
	Globally: OFF
	Per track: ON
Effects plugins NOT ACTIVE

UPSAMPLING:
SoX not in use
SoX filter parameters
Bandwidth at 0dB = 99.5
Filter max length = 30000
Anti-aliasing = 100
Phase = 66

AUDIO VOLUME:
Max allowed volume: 100
Replay Gain: None
SW volume control: OFF

LIBRARY SETTINGS:
Sync list: 1 folders
AUTO: /Users/rene/MyMusicAudirvana
iTunes/Music library synchronization: not synchronized
Library database path: /Users/rene/Library/Application Support/Audirvana/AudirvanaPlusDatabaseV2.sqlite

ACTIVE STREAMING SERVICES

=================== AUDIO DEVICE ========================

CoreAudio audio path, buffer I/O frame size: 512

Max. memory for audio buffers: 13312MB

Local Audio Engine:
Exclusive access: Enabled
Integer mode: Enabled

Preferred device:
Scarlett Solo USB
Model UID:Scarlett Solo USB:1235:8211
UID:AppleUSBAudioEngine:Focusrite:Scarlett Solo USB:Y7UAYVW950E595:1,2

Currently playing in Integer Mode:
Device: 2ch Non-mixable linear PCM Interleaved 24bits little endian Signed Integer, 8 bytes per frame 44.1kHz

Active Sample Rate: 44.1kHz
Hog Mode is on

Bridge settings:
Sample rate limitation: none
Sample rate switching latency: none
Limit bitdepth to 24bit: OFF
Mute during sample rate change: OFF

Selected device:
Local audio device
ID 0x3a Scarlett Solo USB Manufacturer:Focusrite
Model UID:Scarlett Solo USB:1235:8211 UID:AppleUSBAudioEngine:Focusrite:Scarlett Solo USB:Y7UAYVW950E595:1,2

6 available sample rates up to 192000Hz
44100
48000
88200
96000
176400
192000
Audio buffer frame size : 14 to 4096 frames
Current I/O buffer frame size : 512
Volume Control
Physical: No
Virtual: No
MQA capability
Auto-detect MQA devices: No
Not a MQA device, user set to not MQA
DSD capability: Unhandled
Device audio channels
Preferred stereo channels L:1 R:2
Channel bitmap: Ox3, layout:
Channel 0 mapped to 0
Channel 1 mapped to 1

Audio channels in use
Number of channels: 2
Use as stereo device only: No
Simple stereo device: Yes

1 output streams:
Number of active channels: 2, in 1 stream(s)
Channel #0 :Stream 0 channel 0
Channel #1 :Stream 0 channel 1

Stream ID 0x3b 2 channels starting at 1
12 virtual formats:
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 192kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 176.4kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 96kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 88.2kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 48kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 44.1kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 192kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 176.4kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 96kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 88.2kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 48kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 44.1kHz

12 physical formats
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 192kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 176.4kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 96kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 88.2kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 48kHz
2 ch Mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 44.1kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 192kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 176.4kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 96kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 88.2kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 48kHz
2 ch Non-mixable linear PCM Interleaved 24 little endian Signed Integer aligned low in 32bit 44.1kHz

Local devices found : 2
Device #0: ID 0x30 Built-in Output Manufacturer: Apple Inc. Model UID: AppleHDA:128 UID: AppleHDAEngineOutput:1B,0,1,1:0
Device #1: ID 0x3a Scarlett Solo USB Manufacturer: Focusrite Model UID: Scarlett Solo USB:1235:8211 UID: AppleUSBAudioEngine:Focusrite:Scarlett Solo USB:Y7UAYVW950E595:1,2

UPnP devices found : 0

This is a very interesting observation and question. Hopefully @damien will give us the explanation. We could learn how communication with DACs exactly works.

Hello @renes, this mean that your device can use 32 bit but it will use 24 bit as a minimum sample rate.

Thank you for this explanation!