AudioBrew

Ted, I’ve been reading your posts for many months on several web sites. I appreciate your insights into a hobby which we all are committed, and I look forward to reading future product review that you are willing to share with the public. In-fact; if it wasn’t for your observations on de-embedding audio data, I might have missed the opportunity to enjoy the amazing sound of SACD via the Atlona AT-HD577. I would like to recommend that members don’t discount the possible audio benefits of the AT-HD577 over the older AT-HD570, until they have a chance to listen to both products. The unique ability of the Atlona AT-HD577 to decode a DSD Bitstream is an important discussion point for the audio community. Otherwise; individuals might purchase the older AT-HD570 product, or another non-DSD compatible de-embedder, under an assumption that there are no sonic benefits to the newer AT-HD577 product. Both John (iWonder) and I have observed an audible improvement when listening to the AT-HD577 via a DSD Bitstream signal. I encourage others to perform this same evaluation and document their findings. If anyone objects to product claims, made by a particular product manufacturer, then I recommend they discuss their disagreements directly with the manufacturer. I have documented verifiable references to Atlona product literature, which clearly indicates THERE ARE MAJOR DESIGN DIFFERENCES BETWEEN THE AT-HD577 & AT-HD570 PRODUCTS. Specifically; differences in the data formats, available for de-embedding. Furthermore, Atlona technical support has verbally confirmed these differences. If anyone is interested in researching Atlona product claims or has any further question regarding Atlona product features, please call them. I have found their technical support group very friendly and eager to answer questions.

Ted, Good comment. You have me wondering the same question; so decided to call Atlona tech support for clarification. Atlona tech support said “The AT-HD577 contains audio format decoding circuitry similar to most home theater surround sound processors. The audio decoding circuitry used in the AT-HD577 supports decoding of DSD data from a SACD source”. They were not able to address the question if a DSD hand-shake is occurring or even if a DSD hand-shake is required for DSD transmission. As stated in the user guide; the AT-HD577 supports de-embedding of the following formats: Dolby Digital, DTS, DVD-Audio, LPCM, SACD, MPCM But will only “Pass” through the HDMI interface these formats: DTS-HD Master Audio & Dolby TrueHD So it’s still not clear if a DSD handshake is occurring or required. An interesting test would be to connect a home theater surround sound processor, which does not support DSD but does support PCM, to the Oppo. If no music output is generated from the analog outputs of the surround sound processor, then we can conclude that the Atlona AT-HD577 is decoding the DSD data, and the Oppo is not internally defaulting to PCM data. Which implies that a hand-shake is not required for transmission of DSD data. However, if music output is generated from the analog outputs of the surround sound processor, then we will know that the Oppo is internally defaulting to PCM data for a surround sound processor that does not support DSD decoding. This also implies that a hand-shake is required for DSD transmission. One additional note: the older Atlona product (AT-HD570) does not list SACD as a supported de-embedded format. The supported de-embedded format for the AT-HD570 include: Optical Output audio format: Dolby 5.1/2 and LPCM 2 channels

Please note: The Atlona AT-HD577 will convert a DSD Bitstream to PCM. The Atlona product manual indicates both LPCM & Bitstream compatibility. In addition the product manual indicates SACD compatibility. The term “De-Embedder” is a little misleading. In fact the Atlona AT_HD577 is actually an audio format decoder, with an internal D to A converter, and Hi-Resolution Coax & Optical Digital Outputs. When my Atlona AT_HD577 first arrived, I was so focused on de-embedding PCM formats from my Oppo BDP-83SE, that I didn’t even consider setting-up the Oppo to output a DSD bitstream (as documented in the Oppo user manual). After I realized the Atlona AT_HD577 was capable of decoding a DSD as a Bitstream, I started comparing the sound of various SACDs using different Oppo configurations. My external DAC is the PS Audio Perfect Wave PWD which displays the frequency of the incoming PCM signal. By far the Best sound was achieved as indicated in the #1 configuration below. The second best sound as indicated in #2, as so on: 1) Oppo configured to output SACD as unconverted DSD in a Bitstream format over HDMI. Then using the Optical output from the Atlona connected to the PS Audio PWD. 2) Oppo configured to convert SACD to PCM data and output in a LPCM format over HDMI. Then using the Optical output from the Atlona connected to the PS Audio PWD. Allowing the Atlona to convert the DSD data to PCM provided a much smother and musically rich reproduction. Musical richness was additionally enhanced using the Atlona Optical output as compared with the Coax output. On specific SACD titles, I experienced a gigantic-enveloping sound stage with amazing dynamics, and the most enjoyable musical flow I have ever experience from any SACD reproduction. However, I am also experiencing several negative issues. When the Atlona converts DSD to PCM there is an added level of “Hiss” very similar to tape hiss, which is present to a lesser or greater degree on every SACD. This may be related to power line noise. I notice the hiss amplitude is much less late at night. Also; the bass reproduction is not as defined as I would like. The sound is definitely impacted by changing HDMI cables. So I have ordered a few rentals from the Cable Company (both HDMI cables and Optical Cables) to see if I am can to improve on the current sound quality. I may also consider an AC power re-generator like the PS Audio Power Plant Premier. Even with the added noise and audio reproduction issues; I’m still happy with the overall improvement in SACD sound reproduction, as compared to using the Oppo BDP-83SE via the analog outputs.