What is the max sample rate an iMac is capable of?

Hello everyone,

I’m running Audirvana v3.5 on an iMac Pro connected to an iFi Micro iDSD Black Label. When I tried configuring Audirvana the screen reported the Mac supported rates as follows - PCM 384 and DSD 128. The iDSD is capable of handling 768k and DSD512.

Is this a limitation of the iMac, macOS, USB or something else?

Thanks.

Select dsd over pcm 1.1 in dac preferences, that allows dsd256 on mac… 1.0 allows dsd128 max… for dsd512, i think If not mistaking, you will need a PC.

Hello,

Thanks for the quick response.

I don’t see any place where I can select dsd over pcm 1.1

Apart from Audio Output Selection under the Audirvana menu or the speaker icon on the screen which only allows the user to select the DAC to connect to, the only other items I can configure are the up-sampling rates and other items like Max memory allocation, Exclusive access, Integer mode, CoreAudio IO buffer and Mute during sample rate change.

Just a little more info - I’m on Audirvana v3.5.34, macOS 10.14.6, iMac Pro (2017) with 64GB RAM.

Under the speaker icon. It shows as DoP 1.1.

Sorry there’s no info below the speaker icon.

Just for completeness - I am also running same version Audirvana on a Mac mini with macOS 10.14 connected to a Ayon Stealth DAC. The DoP option is available in the Audio Settings screen. This is very strange.

Can someone shed some light on this?

Thanks.

Or rather, there is a line with the output sampling speed beneath the speaker icon. It says “32/384kHz Stereo” whereas with the Mac mini the line says “32/384kHz int”. These are the settings I made for upsampling in Audirvana.

The diff between the 2 DACs is that the iFi can render up tp 784k and DSD512 whereas the Ayon is limited to 192k and DSD128.

Under the speaker icon, “Native DSD streaming method”:

Disable the software volume control.

@bitracer,

Thanks for the help you are giving me.

I checked the Audio Settings again and I do not see the option for Native DSD streaming. I am attaching a screen print

If I turn off the auto MQA option I get the following -

As you can see there is no such setting for Native DSD streaming and yet the iDSD is capable of playing pure DSD files.

I hope you can help me sort this out. Thanks.

Before I forget, I have turned off software volume control (it was never on in the first place).

Disable software volume control, disable upsampling.

Restart Audirvana and reconnect your DAC. This menu option should appear.

If it doesn’t get resolved please post here the debug info.

Thanks again.

I tried your suggestions. It made no difference. The debug info follows -

Audirvana Mac Version 3.5.34 (3564)
macOS 10.14.6 with 65536MB RAM

Registered to Stephen Ng

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: 4 folders
AUTO: /Volumes/Digital_Music/HD_Tracks
AUTO: /Volumes/Digital_Music/Kerry
AUTO: /Volumes/Digital_Music/MyRIPs
AUTO: /Volumes/ThunderBay/Music/Music Purchased
iTunes/Music library synchronization: not synchronized
Library database path: /Users/sng/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: 62464MB

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

Preferred device:
iFi (by AMR) HD USB Audio Output
Model UID:iFi (by AMR) HD USB Audio:20B1:3008
UID:AppleUSBAudioEngine:iFi (by AMR):iFi (by AMR) HD USB Audio:00000000:1

Active Sample Rate: 192kHz
Hog Mode is off

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 0x53 iFi (by AMR) HD USB Audio Output Manufacturer:iFi (by AMR)
Model UID:iFi (by AMR) HD USB Audio:20B1:3008 UID:AppleUSBAudioEngine:iFi (by AMR):iFi (by AMR) HD USB Audio:00000000:1

8 available sample rates up to 384000Hz
44100
48000
88200
96000
176400
192000
352800
384000
Audio buffer frame size : 58 to 4096 frames
Current I/O buffer frame size : 512
Volume Control
Physical: No
Virtual: No
MQA capability
Auto-detect MQA devices: Yes
MQA Renderer device
DSD capability: DSD via PCM 1.0
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 0x54 2 channels starting at 1
16 virtual formats:
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 384kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Float 352.8kHz
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 32 little endian Signed Integer 384kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 352.8kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 192kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 176.4kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 96kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 88.2kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 48kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 44.1kHz

16 physical formats
2 ch Mixable linear PCM Interleaved 32 little endian Signed Integer 384kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Integer 352.8kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Integer 192kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Integer 176.4kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Integer 96kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Integer 88.2kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Integer 48kHz
2 ch Mixable linear PCM Interleaved 32 little endian Signed Integer 44.1kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 384kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 352.8kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 192kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 176.4kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 96kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 88.2kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 48kHz
2 ch Non-mixable linear PCM Interleaved 32 little endian Signed Integer 44.1kHz

Local devices found : 2
Device #0: ID 0x53 iFi (by AMR) HD USB Audio Output Manufacturer: iFi (by AMR) Model UID: iFi (by AMR) HD USB Audio:20B1:3008 UID: AppleUSBAudioEngine:iFi (by AMR):iFi (by AMR) HD USB Audio:00000000:1
Device #1: ID 0x47 iMac Pro Speakers Manufacturer: Apple Inc. Model UID: Speaker UID: BuiltInSpeakerDevice

UPnP devices found : 1
Device #0: ID 0x0 DMR-BWT955 UID: uuid:4D454930-0300-1000-8000-80C7552AA6D7 Location: http://10.0.0.3:60607/80C7552AA6D7/Server1/ddd

Maybe @Damien3 can help you here. Don’t know why the DSD settings don’t appear.

@bitracer, Thanks for your help.

I hope Damien is following this :grinning:, or should I contact him directly?

Hello @swcng2001, the latest firmware of iFi for your DAC introduced MQA, unfortunately this latest version make your sample to be cut by half. The fact that you don’t have DSD over PCM option is because we identified this DAC earlier and enable this setting automatically.

You then need to make a decision by staying with this firmware and have MQA capability or going on the older one with DSD 256 for MacOS.

Hello @Damien3,

Thanks for the clarification.

As I understand it, any Mac is only capable of handling PCM 384kHz and DSD256. This is a limitation of core audio which is Apple’s driver for audio.

There are no workarounds as far I can find (even if we go down the route of using ethernet instead of USB) as its Apple’s limitation.

To add to my specific problem it seems the iFi Micro iDSD Black Label, even though its hardware is capable of the higher sampling rates, the fact that they have introduced new firmware to handle MQA further limits on the max DSD rate to 128. I have a choice to downgrade to a previous version which does not support MQA which will give me the DSD256 capability.

What a wonderfully complex and confusing world we live in???

Thanks everyone for your help. I hope it helps anyone else who is investigating this.

MQA is crap anyway…
go for DSD256, easy choice for me

I’m with you on that but don’t tell anyone else :sweat_smile: :sweat_smile: The MQA secret service will hound us.

I don’t think that’s the case. My Macs send PCM up to 768kHz via USB:

@dotnet,

Thanks for your reply.

I’m confused. How did you bring up that Audio Devices window. Is it an Audirvana pop up or part of macOS System Preferences?

Audio midi setup in utilities folder in applications folder