Functional Description

The Vanity module can be installed into any suitable CD / SACD / DVD-Audio player and transform it into a high resolution digital audio source. Internally it connects to the digital interface between player's own DAC chips and decoders.

Digital Output

The Vanity module provides an additional connector on the player's rear panel - a transformer isolated BNC Coaxial. The module uses industry standard S/PDIF Digital Audio Interface format which is compatible with any high resolution outboard DAC.

In order to ensure maximum compatibility, the module can be configured to limit maximum output samplíng rate to 96kHz and / or limit output bit depth to 16bit via internal DIP switches.

The new revision of Vanity module features digital output reclocking. This technique prevents noise from digital processing inside FPGA reaching the output and therefore significantly reduces jitter of the SPDIF signal.

Zero Alias Filters

We have identified a major flaw in vast majority of digital filter implementations throughout the industry. Common digital oversampling filters, asynchronous sample rate converters and DSD to PCM converters are all affected by this issue. We understand the reasons for these faulty design practices – which is due to commercial cost pressures. A correctly designed digital filter with similar basic characteristics (such as passband corner frequency and stopband attenuation) would require around four times the silicon area - something that no “commercial” chip producer is willing to accept, for this reason they continue to produce sonically compromised designs. At Audiopraise we developed our own precision digital filters designed from the ground up to meet demanding applications.

DSD to LPCM Conversion

Direct Stream Digital was originally conceived with maximum simplicity in mind, providing the simplest signal path between A/D and D/A converters. The idea being to eliminate the negative effects of digital decimation and interpolation filters. However in reality there are a number of disadvantages to DSD. One of the most serious is the excessive wideband ultrasonic noise that can cause several problems downstream in the replay chain. This results in compromises in the design of post-DAC analogue filters - either they are sonically transparent but pass too much ultrasonic energy or they are sonically inferior but with sufficient attenuation of ultrasonic energy. This is a situation resembling the very first CD players which required complex analogue brick wall filters with sonically poor properties.

Fortunately with our Zero Alias Filters, we have superior digital filters at our disposal than the manufactures of SACD had when they made their design decision to go with raw DSD as a distribution format despite its technical deficiencies. Our Zero Alias Filters completely remove unwanted ultrasonic noise without compromising sonics. Audiopraise DSD to LPCM converter is also designed in such a way as to eliminate the effects of improperly designed oversampling filters found in DAC’s. This way you can take advantage of SACD's higher resolution without it's negatives.

Synchronous LPCM Upsampling (Over-Sampling)

Many people would argue about the need for upsampling, with the valid argument that upsampling cannot extract any extra information from the original recording. This statement is very valid, however “producing” extra information is never what upsampling or oversampling tries to accomplish. Oversampling‘s purpose is to dramatically simplify the design of the analogue post-DAC filter by performing the hard work in the digital domain instead of analogue domain. Not many people are aware that 8x oversampling filters are integrated within nearly every DAC in existence and that these converters do not in fact operate at 44.1kHz when replaying CD, but at a much higher „Oversampled“ rate. So why do we need extra upsampling when we already have oversampling already integrated within our DAC? The reason is simply a question of quality. Unfortunately, the performance of common oversampling filters range from mediocre to poor. We found this to be one of the main factors for the commonly perceived 'digital' sound - lack of sound stage and depth, with an unnatural “busy“ feel.

The 2x Upsampling performed by our Zero Alias Filter practically substitute the first stage of DAC's own oversampling filter – from an audio quality perspective, the most influential one. We've experienced a dramatic improvement in overall sound quality on various DAC’s featuring currently the best oversampling filters available. In fact we shouldn't even be surprised considering what we know about those filters, nonetheless the difference our Zero Alias Filters made impressed us. Let them impress you...

Custom Digital Signal Processing

Vanity can also serve as an universal high perfomance platform for custom signal processing. This may include digital filters, PDM and PWM modulators, signal generators, analyzers and other. Please send us an email to place a custom firmware inquiry.