audiopraise VanityPro Multi-Channel HDMI Digital Audio Extractor with Built-In Advanced Signal Processing User Manual

Vanity PRO
User Manual

Introduction

The Vanity PRO is a multi-channel HDMI digital audio extractor with advanced signal processing built-in. It enables the user to turn virtually any compatible HDMI source into high quality, up to eight-channel digital audio transport which supports PCM and DSD audio formats.

HDMI Audio

HDMI is the primary method of transporting AV signals in the consumer environment. It works great with high-resolution audio and video, but it has never found its way into the hi-fi world.
Apart from some non-technical reasons, one of the biggest issues associated with HDMI audio is the quality of the clock recovered from the HDMI stream and the electrical noise associated with it. Despite many improvements in the newest HDMI receiver devices, the recovered clock always suffers from high levels of phase noise. While this is usually not an issue in consumer audio – home theatres, soundbars, etc., in the discipline of critical listening the imperfections of HDMI audio are instantly noticeable. Also, HDMI  audio is notoriously known to be sensitive to various forms of electromagnetic interference, cabling quality, ground loops, and in the hi-fi world generally considered inferior when compared to dedicated digital audio transport methods such as SPDIF, AES/EBU, or proprietary links based on the I2S bus.
There is usually nothing wrong with the audio data itself, provided the receiver can take advantage of all the digital formats and sampling rates available on the source site. What can cause issues is mainly the way the audio data is packed and interleaved with the video data in a high-frequency digital signal and eventually recovered on the HDMI  receiver (sink) side. There are many cheap HDMI audio extractors on the market, and some of them are able to output digital audio via S/PDIF up to a 192kHz sampling rate.  But they still don’t come even close to a good digital transport in terms of audio quality.

Vanity PRO
How is the VanityPRO different from all the other HDMI audio extractors? It basically addresses all the imperfections associated with the HDMI audio, one by one, with a ton of extra features the others don’t have.

• Galvanically isolated HDMI interface from the sensitive audio output circuitry with separate power connections.
• Ability to receive PCM and DSD formats at all sampling rates (PCM up to 192kHz).
• Sophisticated clock recovery using our in-house developed DBLL (Digital Buffer Locked Loop) system with two custom-made low noise oscillators.
• High-quality DSD to PCM conversion with user-configurable parameters.
• DSD to DoP conversion for raw DSD data output.
• Up to 8-channel support.
• Ultra-low noise regulators for the clocks and digital audio outputs.
• HDMI link monitoring and diagnostics.
• Configurable output connectivity for stereo and multi-channel setups.

Description

Front

1. RGB LCD 320*240 Screen
2. Stand-by and Status LED Indicator
3. Rotary Encoder with Push-button

Back

1. HDMI DC Power Input, 5V/1A, USB-C
2. HDMI Output
3. HDMI Input
4. Digital Audio Output Board (Stereo board shown)
5. Word-Clock Output (44.1kHz to 192kHz)
6. Super-Clock Output (22.5792MHz or 24.576MHz)
7. Service Port, USB-B
8. Audio DC Power Input, 5V/1A, USB-C

Output Boards
For maximum flexibility, the VanityPRO features an interchangeable output module with various configurations of the output connectors. There are 4 options in total, covering stereo and 3 multichannel configurations with RCA, BNC, and XLR connectors.

User Interface

The unit is operated using a rotary encoder with a push-button function and an LCD screen. The navigation is easy through a series of screens with options and metering &  diagnostic data.

• Turing the rotary encoder left and right changes the screen moves between options in a configuration menu or selects from multiple options.
• Pushing the knob in one of the two configuration screens will enter the sub-menus.
• Pushing the knob with an item highlighted will enter the item configuration.
• Once the correct option is selected by turning the knob left and right, pushing the knob again will confirm the selection and return to the menu.
• To exit the menu and go back to the screen selection, a long (2 seconds) push of the knob is required.
• The knob is also used to toggle between stand-by and normal operation of the unit. Long push the knob to turn the unit on from the standby mode. Long push the knob in the home screen to enter standby mode.

Installation

AV Signals

The typical installation of the Vanity PRO consists of an HDMI signal source capable of delivering all compatible digital audio formats and sampling rates, such as a universal layer or a PC and a stereo/multi-channel DAC or audio processor, that can take advantage of the high quality and high-resolution S/PDIF or AES/EBU signals. Optionally, the user can connect an HDMI sink such as a TV or a projector to the HDMI output of the VanityPRO for video pass- through.
The HDMI connectors are quite delicate and should be plugged and unplugged carefully without excessive force or wiggling to prevent damage. The same applies to the power USB-C connectors.

Power
The Vanity PRO has two independent power inputs. One for the HDMI part, one for the audio part. The power supplies must meet the voltage and current requirements (see specifications).

It is strongly recommended to use high-quality 5V power supplies, ideally linearly regulated. Alternatively, multi-port premium and low noise USB chargers can be used. The power quality directly influences the quality of the output audio signal. Therefore, high-quality power supplies are essential.
Both parts of the unit can be powered independently. The HDMI part is capable of working on its own without the audio and control part powered up.

Synchronization Clocks

There are two synchronization clock outputs provided on the BNC connector with 50Ω output impedance. The purpose of these two clock outputs is to synchronize any downstream audio devices such as a DAC equipped with a synchronization clock input. The advantage of external synchronization is usually in better and cleaner clock signal available for the digital to analog conversion process compared to a clock recovered from a S/PDIF or AES/EBU stream.
There are “Word Clock” and “Super Clock” signals provided. The Word Clock is a sampling frequency clock Fs, while the Super Clock is either 22.5792MHz or 24.576MHz.

Theory of Operation

Block diagram

HDMI Extractor
The HDMI interface has combined functionality of an HDMI extractor as well as a repeater.
The main difference between both modes is in handling the EDID data. While in the extractor mode (default), full audio capabilities in terms of formats (PCM/DSD) and sampling rates are reported back to the HDMI source, the repeater mode passes through the EDID information from the connected downstream HDMI sink (TV or projector). The other difference is that in the extractor mode the audio data are removed from the output HDMI stream and only the video part of the original stream is passed through.

Clock Recovery and Jitter Reduction

To deal with one of the major technical imperfections of the HDMI interface, the Vanity PRO  uses a pair of low-jitter digitally controlled oscillators and an adaptive control algorithm to lock onto the incoming audio frequency and output the audio data with perfect timing, completely free of any jitter or noise of the HDMI interface.

Audio data from the HDMI interface is buffered in FIFO memory and clocked out with local high precision oscillators. As a result, the output signal is completely isolated from the noisy HDMI domain – interferences from the power supplies, video circuits, etc.

Eye diagram of the output S/PDIF signal. Generic HDMI audio extractor – left Vanity PRO– right.
The effectiveness of the clock recovery system can be seen in the two oscilloscope waveforms above. There are waveforms with persistence enabled of the output S/PDIF  signal – from a generic HDMI extractor on the left and the Vanity PRO on the right. The time base is delayed by 10ms to show accumulated phase noise using the color grade.  The difference in signal edge timing and definition can be clearly seen.

DSD Processing Engine

DSD to PCM Conversion
One of the key features of the VanityPRO is the DSD signal processing and conversion to the PCM format. We have developed a high-quality DSD to PCM conversion algorithm to enable owners of stand-alone DACs to enjoy their favorite SACDs or DSD recordings in the highest quality possible. The conversion engine has user adjustable characteristics to slightly vary the frequency roll-off and subsequently the amount of residual ultrasonic noise inherent to the DSD format. The user can also control the output sample rate and bit depth.

The DSD to PCM conversion algorithm implemented in the Vanity PRO sets 0dB SACD level equivalent to -3dB(FS) PCM level. This approach preserves maximum quality,  provides sufficient headroom for clipping-free signal peaks and over-modulation, and still does not unnecessarily reduce playback volume in comparison to PCM playback.

DSD and PCM Level Matching
The DSD to PCM conversion produces an overall signal level 3dB lower compared to PCM playback. This is usually not an issue, but thanks to the precision volume control function, the output levels of DSD and PCM playback can be matched by attenuating the PCM signal by 3dB. A positive side effect is that this helps to create sufficient headroom for inter-sample peaking with PCM material and DACs that don’t provide such headroom by design.

DoP v1 output mode
The Vanity PRO can be also set to output DSD signal in so-called DoP format (DSD Over PCM). This allows the user to send raw DSD material directly to a DoP compatible  DAC. More details can be found here: http://dsd- guide.com/sites/default/files/white-papers/DoP_openStandard_1v1.pdf

DSD 4.0 Down-Mix
To achieve the best performance during digital DSD playback, it is essential to avoid the DSD to PCM conversion done by the HDMI source. Universal players can sometimes perform such tasks for downmix purposes. For this reason, the widely used 4.0 speaker configuration is covered by the dedicated down-mix algorithm implemented in the  Vanity PRO. The algorithm preserves the overall signal level balance between channels, and it can be described as follows.

FLmix = 0.5FL+0.25C+0.25LFE
FRmix = 0.5FR+0.25C+0.25LFE
SLmix = 0.5SL
SRmix = 0.5SR

To fit the mixed Center and Low-Frequency Effect channels into the front channels, the overall signal level is shifted by -6dB. No additional signal normalization or scaling is applied. Since the down-mix processing is carried out with full precision, there is no adverse effect on sound quality such as reduced dynamics or worse noise figures. The 4.0  downmix can be performed correctly only with multi-channel 5.1 DSD tracks. If the Vanity PRO is connected to a universal player, the SACD playback priority should be checked or the correct setting.

Volume Control
A part of the processing engine is also full precision volume control. It is used not only for DSD and PCM level matching but also gives the user full control of the overall output level. With a 0dB setting (maximum volume) the digital signal path is a bit accurate.
All the digital audio processing is performed by a medium-sized FPGA. The firmware for the FPGA is user-upgradeable, together with the main processor firmware, to add new features and functionality in the future.
Dielectric Barrier
There is a galvanic barrier put between the HDMI and the audio parts to limit the electromagnetic noise from the HDMI domain influencing the sensitive audio and clock circuits in the audio domain. Another advantage of this feature is the option to power the two functional parts independently from separate power supplies. The audio part can be powered from high quality and low noise, possibly linear, power supply without the risk of being plagued by the noise from the switching regulators on the HDMI side.

Menu system
The menu system is structured into several screens. Some screens are used for monitoring the HDMI stream and incoming audio signal properties, while others are used to set the system and audio processing parameters.

Home Screen
The home screen provides a basic overview of the HDMI link status and digital audio properties.

MODE : Indicates whether the incoming audio format is PCM or DSD.
SAMPLING RATE: Indicates incoming sampling rate. Valid sampling rates are 44.1, 48, 88.2, 96, 176.4, and 192kHz. The sampling rate indicator also shows the status of the clock recovery system. When the algorithm is actively locking onto the incoming clock rate, the indicator turns orange.
BIT RESOLUTION : Indicates detected bit resolution in the range between 10 and 24 bits and MUTE when no valid bits are present. The bit depth detection algorithm monitors the real number of bits used (continuously changing). It is possible that the detected bit resolution sporadically changes during playback depending on the actual signal conditions and playback method. This applies primarily to compressed audio sources.
SIGNAL STATUS: Indicates the status of the incoming audio signal, RUN or STOP.
CHANNELS: Indicates a number of valid channels in the range from 2 up to 8.
HDMI IN and HDMI OUT: Indicate whether an HDMI link is established on the input or the output connector. The red color indicates no HDMI connection. The green color indicates an established HDMI link.

Audio Setup
In this screen, the user can configure several parameters of the DSD to PCM conversion the algorithm, DSD output mode, 4.0 downmix, and output volume.

Sampling Rate: Sets the output sampling rate for DSD to PCM conversion. The options available are 88.2 and 176.4kHz.
Bit Resolution: Sets the output bit depth for DSD to PCM conversion. The options available are 16 and 24 bits. The
The 16-bit option can be useful for owners of so-called non-oversampling (NOS) DACs or older devices designed to accept 16-bit word length only. In all other cases, the 24-bit options should be selected.
Filter : Sets the DSD to PCM conversion filter characteristics. There are 4 options available. Sharp HB, Slow HB, Sharp LB, and Slow LB. See the following paragraph for filter details.
PCM Matching: Enables or disables the PCM and DSD output level matching function. With the 0dB setting, PCM is passed through a bit accurately without attenuation. With a -3dB setting, the PCM material gets attenuated by 3dB to match the output level from the DSD to PCM converter.
DoP Output : Enables or disables raw DSD output in the DoP format. Use only if your DAC can accept the DoP signal.
DSD 4.0 Downmix: Enables or disables the internal DSD 4.0 downmix function.
Output Volume: Sets the fixed level of the output signal. The range is from 0dB down to -100dB. Select 0dB for a bit accurate signal path with no attenuation.

Filters Characteristics
There are four conversion filter characteristics available in the Vanity PRO. The filters differ in their steepness and the amount of attenuation of the ultrasonic noise. All four characteristics can be used when the output sampling rate is set to 176.4kHz and only two with 88.2kHz. The filters optimized for 88.2kHz output sampling rate have “LB”  suffix for “Low Bandwidth” and filters optimized for 176.4kHz output sampling rate have “HB” suffix for “High Bandwidth”. The frequency plots below show the output spectrum of the DSD test signal with 1kHz tone at 0dB converted to PCM 24bit and 176.4kHz. Typical bumps if the DSD noise floor can be observed in the audio frequency band.
Sharp LB
This filter optimized for 88.2kHz output sample rate has a sharp roll-off with a cut-off frequency of approximately 20kHz. Chose this filter for high attenuation of the ultrasonic noise.

Slow LB
This filter optimized for 88.2kHz output sample rate has slow roll-off with a cut-off frequency of approximately 25kHz. Chose this filter for better transient response with a slightly higher level of ultrasonic noise.

Sharp HB
This filter optimized for a 176.4kHz output sample rate has a sharp roll-off with a cut-off frequency of approximately 44kHz. Chose this filter for high bandwidth and high attenuation of the ultrasonic noise.

Slow HB
This filter optimized for a 176.4kHz output sample rate has slow roll-off with a cut-off frequency of approximately 55kHz. Chose this filter for the best transient response at the expense of the highest level of ultrasonic noise.

There is no general rule for which filter characteristic is the best. The best sounding filter characteristic should be selected by practical listening and evaluation of sonic qualities for each specific audio chain configuration. With a very linear audio system with sufficient analog path bandwidth, the Slow HB filter at 176.4kHz would be expected to be preferred as it maintains the highest level of DSD bandwidth (including the ultrasonic noise) and the best transient response.

System Setup
The system setup allows the user to configure the screen, standby LED, and synchronization clock outputs.

HDMI Mode: Sets the operation mode of the HDMI interface.
Two options are available: Extractor and Repeater.
The default mode is Extractor, and this setting should be used for normal operation. In the Repeater mode, the HDMI stream is passed through as is, including the audio data. Also, the EDID data are passed through from the HDMI TX port back to the HDMI source, bypassing the internal EDID. The Repeater mode should be used only for debugging the HDMI connectivity as it does not add any functionality over the default Extractor mode. When the mode is changed the Vanity PRO automatically restarts with the new settings.
Screen Brightness: Sets the screen brightness in the range 0-100. 0 is minimum brightness and 100 is maximum brightness.
LED Brightness: Sets the brightness of the standby LED. Three settings are available – Low, Mid, and High.
Word Clock Out: Enables or disables the Word Clock output.
Super Clock Out : Enables or disables the Super Clock output.
HDMI AV Info
In this screen, the user can see various parameters of the received HDMI stream as detected by the HDMI interface. The data is extracted from the HDMI Audio Info Frame as per CEA-861-D.
Channel Count: Indicated number of channels in the “Audio Channel Count” (CC bits). Value can range from 2 to 8.
Channel Mapping: Indicated number of “Channel Configuration” (CA bits) in hexadecimal format. Please refer to CEA-861-D section 6.6 for details.
Level Shift: The indicated value of attenuation as “Level Shift Value” (LSV bits) converted to dB. Value can range from 0dB to 15dB.
Format: Indicated current video format. There are three possible values – STD for Standard, EXT for Extended covering all 4Kx2K resolutions, and 3D covering all 3D  formats.
Colour Depth: Indicated Colour Depth (CD bits). There are five possible values – 24, 30, 36, and 48 bits per pixel and “–“ for not indicated.
Colour Format: Indicated Colour Format (Y bits). There are three possible values – RGB, YCbCr 4:2:2, and YCbCr 4:4:4.

Audio Meters

For a quick overview of the audio signals’ presence and incoming audio signal levels, the Vanity PRO features an 8-channel audio level meter. Each channel has a dedicated meter with a range from 0dBFS down to -48dBFs and tri-color grade. The channel names are coded with standard abbreviations. The additional names in the brackets follow the naming convention of the CEA-861-D standard.

• FL – Front Left
• FR – Front Right
• C – (Front) Center
• LFE – Low-Frequency Effect
• SL – Surround (Rear) Left
• SR – Surround (Rear) Right
• SBL – Surround Back (Rear Center) Left
• SBR – Surround Back (Rear Center) Right

System Status
This screen shows the overall system status, health, and operational parameters.

POWER : Shows internal voltage measurements of various voltage rails and Audio side power input current.
AUDIO: Shows various audio parameters which are available in the home screen as well as oscillator selection, oscillator control voltage, and audio buffer utilization.
HW: Shows internal health checks for the key components –HDMI interface, FPGA, and the screen.
HDMI: This shows the ID information and status of the HDMI interface.
PRODUCT: This section shows the product-related information, such as serial number, hardware version, and firmware (SW) version. Information from this section should be always provided when support is required.

Software Update

The Vanity PRO is built on a completely programmable processing and control platform utilizing a medium-size FPGA and a 32-bit processor. New features and functionality can be added at any time and the firmware can be upgraded by the user through an easy-to-use Windows PC app.
To update the software, the user must put the unit into firmware update mode and follow a few simple steps.

• Power off or unplug the power cable of the audio side.
• Pres and hold the encoder knob.
• Apply/connect power to the audio side.
• Wait 2-3 seconds before releasing the knob.
• Connect USB-B cable to the Service port.
• Verify that the unit reports itself in the device manager as “STM Device in DFU Mode”. If not, please install the STM DFU drivers provided.
• Run the Audiopraise Firmware Loader. It requires MS C++ 2013 Redistributable to run.
• Verify the file has been correctly loaded. Select the new firmware file and hit the Upgrade button.
• Wait for the firmware to load. Once the new firmware has been verified, you can close the Loader tool and power cycle the unit.
• The Vanity PRO now should start with the new firmware. You can verify the firmware version in the System Status screen.

Troubleshooting

The Vanity PRO implements a robust system of its own health monitoring. The status and functionality of all major components are continuously monitored and reported in the System Status screen. Should the user experience any non- standard or unexpected behavior, diagnosing the potential issue is easy and straightforward.
Before a fault is suspected, the user should make sure that the unit is correctly installed, the power, HDMI, and digital audio cables are properly connected and secured (BNC connectors). Also, the HDMI source should be checked for correct operation and configuration. The Vanity PRO might not be receiving the expected audio format, sampling frequency, or any audio at all due to incorrect configuration of the HDMI source – universal player, streamer, or computer. With computers, the HDMI audio support is sometimes restricted or non-existent due to software drivers. The Vanity PRO has been extensively tested with many different Blu-ray and universal players with positive results.  With Windows-based PCs, getting the HDMI audio to work sometimes required trial & error experiments with HDMI audio drivers and settings.
The table below contains a non-exhaustive list of some issues the user might experience, mainly due to the large variability in device configurations the VanityPRO can be used with.

Issue

| Possible cause|

Solution

---|---|---
HDMI Error reported at the start-up.| The HDMI port has no power.

| Check the power connection for the HDMI port and reboot the unit.
The audio sampling frequency indicator remains orange.| HDMI source signal is unstable or outside of frequency stability specifications.| Use different HDMI signal sources.
No audio from downstream DAC, or DAC unlocked.| SPDIF/AES cable not connected or audio sampling frequency too high.| Check the connections. Set DSD to PCM sampling frequency to 88.2kHz
Occasional dropouts in the reproduced audio| DAC with an ESS chip might be too sensitive to frequency adjustments. See Note 1.| Consult the user manual of your DAC for DPLL adjustment.

Note 1: The user might experience occasional dropouts in the audio signal with a DAC based on an ESS (Sabre) DAC chip.
The jitter attenuation function of this chip called DPLL has several settings and with certain combinations of the DAC’s local oscillator and the DPLL setting the DAC chip may momentarily unlock when the Vanity PRO is adjusting its own audio clock. Many ESS chip-based DACs have the DPLL settings exposed to the user and using a lower  DPLL setting usually fixes the problem.

Specifications

HDMI

• Version 2.0a
• 1x input and 1x output for pass-through

Digital Audio Outputs

• 8 or 2 channel (stereo) output module options
• 4xBNC/RCA/XLR for 8-channel output
• 1xXLR + 1xBNC + 1xRCA + 1x TOSLINK for 2-channel output
• protocols: S/PDIF (IEC958 / EIAJ CP1201), AES/EBU and TOSLINK
• optional multichannel I2S output module with CMOS 3.3V levels
• transformer isolated outputs
• output impedance: 75Ω for BNC/RCA and 110Ω for XLR
• linear PCM 16/24 bits
• supported sampling rates: 44.1 / 48 / 88.2 / 96 / 176.4 / 192kHz

S/PDIF Re-clocking

• 2x custom low jitter on-board VCXO
• digitally controlled frequency tuning, fc<<1Hz
• ultra low-noise power regulators for VCXO and TX circuits

High Quality DSD to PCM Conversion

• custom developed Zero Alias Linear Phase Filter
• 37bit arithmetic / 47bit accumulator
• output sample rates: 88.2kHz / 176.4kHz
• 4 selectable DSD to LPCM filter characteristics
• full precision 4.0 DSD down-mix option
• DoP v1 output encoding of raw DSD

Full Precision Volume Control

• less than 0.001dB gain error
• bit accurate volume bypass at 0dBFS
• TPDF dithering
• PCM and DSD level matching outputs PCM and DSD at the same levels

Synchronization outputs

• Word-clock output: BNC, 50Ω impedance, 44.1 / 48 / 88.2 / 96 / 176.4 / 192kHz
• Super-clock output: BNC, 50Ω impedance, 22.5792MHz or 24.576MHz

User Configurable Functionality

• DSD to LPCM output sampling rate: 88.2kHz / 176.4kHz
• DSD to LPCM output bit depth settings: 16 / 24bit
• PCM and DSD output level matching enable/disable
• dedicated DSD 4.0 down-mix enable / disable
• DoP v1 output encoding enable / disable
• 4 user-selectable DSD to LPCM filter characteristics
• Adjustable output gain (volume) with 1dB step

HDMI and Audio Monitoring & System Diagnostics

• Monitoring of HDMI stream parameters
• 8-channel audio level metering
• Comprehensive system health diagnostics

Power

• separate power for HDMI and audio sides via USB-C connectors
• 2x DC input 5V / 1A

Dimensions & Weight

• w/d/h: 266/183/65 mm, including the output connectors
• weight: 1kg

Revision History

Date

| Version|

Description

---|---|---

16.10.2021

|

1.0

|

Initial release

25.10.2021

|

1.1

|

Added Troubleshooting table

18.11.2021

|

1.2

|

Added Troubleshooting info related to ESS DACs

Disclaimer

The product has been designed and manufactured using high-quality materials in accordance with best practices in the industry and international harmonized safety standards.  Audio praise accepts no responsibility for any damage or injury caused by incorrect installation, use, or operation of the product.

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