Which Naim CD players/ NDAC utilize HDCD? I miss this feature from my previous CDS3.
thanks
One for @Richard.Dane he knows this chipset.
CDX, CDS2 - PMD100
CDX2, CDS3, CD5x, CD5xs - PMD200
If you wish to rip an HDCD disc and retain at 20bit then Dbpoweramp has an HDCD plug-in that can do this and rips to a 24/44.1 file
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Further to Richard’s reply - the HDCD uses the old Pacific Microsonics - or compatible - CD DSP chipset that decoded HDCD. (PMD-100 and PMD-200 introduced in 2000)
The DACs and streamers do not contain these chipsets as they are specific to CD DSP and can’t decode HDCD from the CD native rip or via SPDIF.
Again as Richard mentioned thare is a reverse engineered piece of software that is available that DBPoweramp and other rippers use that emulate most of the HDCD functions and wraps the new digital audio signal in a 24 bit sample file.
It’s not true HDCD and I understand it doesn’t map all the HDCD functions but it does most of the key ones and works pretty well.
Native HDCD has an approximate resolution of 20 bits - but it does vary on content type. 20 bits is not a recognised standard sample size so 24 bit is used, with approx four bits effectively discarded.
HDCD itself uses the least significant bit in the 16 bit sample word information from the CD to control the filtering and companding functions of HDCD within the Pacific Microsonics chipset.
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Thanks gentlemen. I will have to check out Dacs that still use the technology today.
if you do find a DAC that supports the Pacific Microsonics chipsets do share here - I have never seen one - mainly perhaps because it would be limited to 44.1/16(20)/2
IIRC Musical Fidelity offered one of their Tank Engines as a DAC with HDCD - Was it the X-DAC? There was also a weird Cambridge DAC that was also a platform that did HDCD.
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JRiver can detect HDCD, and according to AI, convert the file to 24 bits. One poster on the JRiver forum went into a bit of detail.
"HDCD detection and decoding is an inexact science since the actual specs have never been publicly released.
"HDCDs implemented several different features, not all of which were used on each release. The peak extend and gain adjustment features are implemented in software decoders, whereas transient filters are typically not implemented. In the Hydrogen Audio list of HDCDs, many of the Steve Hoffman Audio Fidelity HDCDs are listed as using transient filters but not peak extend and gain adjustment. So, they are HDCDs, but the software decoders will do nothing to them, since all they implement is the transient filters.
“For example, Faces - A Nod Is As Good As A Wink… (AFZ026) and Deep Purple - Who Do We Think We Are (AFZ027), the 2 numbered releases just before Montrose and also released in 2005 only have transient filters implemented according to the ffmpeg analysis.”
I think the burning question is whether anyone has actually heard any difference to the sound with HDCD ?
IIRC, several, perhaps many Linn label CDs were HDCD. To my ears, whether it’s the recording quality and/or the enhanced format (via CD555), they sound very good.
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Yes, as per my earlier posts, you shouldn’t confuse reversed engineered HDCD emulation with actual HDCD DSP decoding that only the Pacific Microsonics / Microsoft chipsets can do, now that the licensing is owned by Microsoft.
Its quite easy to detect to the HDCD operand signals in the least significant bit of the audio, and there is a free ware/publicly available reversed engineered piece of software that emulates the main HDCD DSP (compression, filtering and companding )functions - and is used by some rippers and related software - but it is not true HDCD - but sounds fairly good and emulates the main functions around PE (peak extend), LLE (low level range extend) and specialist reconstruction DSP filtering (Decimation/Transient Filtering ) that matches the HDCD encoding to improve linearity and phase linearity… I think its these latter functions that are mostly omitted in the software emulators as perhaps require specific hardware chipsets.
If a software vendor was using certified and licenced Microsoft decoding software and the platform running them was powerful enough then it could theoretically offer full HDCD in my opinion, but I am not aware of any such case nor is Google.
The HDCD IPR is proprietary and commercial in confidence that is why its not published… but if you use the correct PM/Microsoft chipsets you can have full HDCD, other than that you can use use reverse engineered software that gets subjectively easonably close for the the main functions.
A copy of an FAQ from Microsoft of the HDCD protocol and what it actually does in layman’s speak.
Hi Simon,
both DACs from Berkeley Audio Design support both HDCD and higher data rates. I’m fairly sure that at least some of the people behind HDCD are involved in the Berkeley components.
thanks - they might have a switchable reconstruction chain and use the Pacific Microsonic chipsets if it detects HDCD on 44.1/16/2 in place of an alternate DSP chain it has for other content.
Architecturally that is possible, but was not aware anyone had actually done it until I read Richard’s and your posts.
The key thing is the Pacific Mircrosonics DSP chipset - or even perhaps rebuilding it within an FPGA under licence?
Berkeley principals were involved in original HDCD Pacific Microsonics project.
As in product development and commercialisation or early concept ideas? As such did they own IPR that they may have jointly sold to Microsoft?
Or were they Pacific Microsonic resources that left to join Berkeley Audio Design?
I ask as I suspect many were people involved with the early conceptualisation… and the main aspect is the commercial licensing to be able to use the technology… which unless anyone can demonstrate otherwise on replay is limited to the specific PM DSP chip.
The CEO and COO were part of the original development team and left after the sale. HDCD is incorporated in their DACs. Very expensive however.
Interesting, CEOs and COOs are not usually part of development teams, they are leading the overall business or business operations which can include the development team/s. Chief Engineers, CTOs, Head of development, etc I can understand as they would likely be involved with the specifics - especially in small businesses