Dual BNC output from PS Audio SACD Transport into Chord DACs Dual BNC

Hi fellow SACD enthusiasts. I’m considering upgrading my trusty olde Marantz SA15-S2 SACD Player to the PST. My Chord TT 2 DAC doesn’t have I2S input, “to unlock the DSD layer from SACDs”. So, I am hoping for the next best thing from the PST; double-rate DoP audio. Chord’s support tell me they haven’t tested this. And such a connection “might not work because of different dual BNC protocols”. Well I can see the PST has BNC L and BNC R. The TT 2 has BNC 1 and BNC 2 ! Anyone tested this?
(I have seen one dealer’s web page claiming the PST’s dual BNC outputs will go nicely with the Chord Dave DAC.)

You have to consider if you are to use the double rate feature of the PST, you would have to use the USB input which have very limited functionality to it. I can play only one file from one flash drive and when I change memory sticks, I have to turn off and on the unit on the back switch before it would read another file. I don’t know if that’s normal, but that’s what my unit does. The PST is meant to be use mainly for playing discs and is about as good as it gets for doing just that, but I wouldn’t use it for playing files. Better to get a good server for double or quad rate DSD.

Thanks. I never thought of using DSD files on a USB stick. For now, I just have ~60 SACDs that I still like to listen too. Some of these are not hybrid SACDs i.e. they’re for SACD players only, no CD layer. (BTW, FYI, I also have the Jay’s Audio CD Transport. Ideal for my collection of ~800 CDs.).

Yes, this PST is simply killer on SACD disc, so much better than the same music on CD’s, but you have to get a I2S DAC to get that DSD layer out.

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If I remember Paul mentioning in a post from a while ago that the SACD licensing protocols only allow handshakes to be between same branded equipment. In other words, if you want to play SACD from your PST, you will need a DS Sr. to make it work.

That was true with the DMP but not the PST. I have used the Holo May KTE DAC with the PST and DSD layer played fine. Paul has gotten around this copy guard thing on the new transport. It will work with other DAC with I2S inputs.

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There is one review of the PST where the reviewer has played SACD back through the Terminator DAC with the I2S connection. The DSD light came on during SACD playback, indicating DSD64.


I got my PST on Saturday and connected it to a Chrod Mscaler/TT2 DAC using the dual-BNC input on the Mscaler.
Tried playing redbook CDs which the Dual-BNC connection in place and you hear popping sounds for almost every track which make this combination unlistenable. Disconnect one of the BNC cables, and you are back in business again.
So unless I got a faulty PST or Mscaler (or both :thinking:), there are compatibility issues :unamused: in the dual-BNC protocols used in both devices.
Edit: I did not try connecting the PST dual BNC outpus to the Chord TT2 DAC directly since the TT2 manual mentions that “Dual BNC is reserved for special operation with Chord Electronics partnering products.”

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My understanding is that the dual-BNC option is there for high-res audio that won’t fit out a single BNC pipe. (I think this would be resolutions over 24/192 such as DXD 24/352.8) However, the problem getting the pure DSD stream off of an SACD is one of encryption, not of bandwidth. The only way to bypass the encryption and get the DSD signal ‘in the clear’ is to use the PS Audio pinout on the HDMI connection. PS Audio have published this pinout spec and several manufacturers (mentioned above) use it; but that is the ONLY way to get the DSD signal off an SACD out of the PST.

As such, the use case for dual-BNC would be playing very high resolution media (2x DSD or DXD) off of a ripped optical disc or a USB drive – neither of which work at all for me with the media I’ve tried so far.

Hi again. I pulled the trigger on purchasing a PST (and a pair of near-new Moon Audio Silver Dragon BNC cables). Here are my findings listening to CDs. (Similar to @2muchgear , except I plugged my PST straight into the TT2 and I got split second mutes (audio “hiccups”) on some CDs, not on others.)

  1. There’s two options when using dual BNC out from the PS Audio SACD Transport , when I’m playing Redbook CDs.
    i) Split
    ii) Stereo
    I tried both. No difference to sound quality and no difference to audio hiccups.
    (Hiccups consistently, precisely at the same points in time on the CD’s track(s).).
    So I guess the TT2 handles both Split and Stereo perfectly well, aside from these brief occasional audio hiccups.
    Sampling rate seen/used by the TT2 for both settings is always 88.2 KHz.

  2. I upgraded the transport’s firmware to the latest & greatest v2.4.2.
    Again no difference; hiccups still consistently, precisely at the same points in time on the CD’s track(s).

3). No hiccups from any CDs when playing Single BNC (44.1 KHz). Ever so slight loss of detail in the music though.

P.S. Responses from friendly and responsive Chord Electronics tech support:

"Hi Trevor, the official position is that the DBNC function on our DACs is exclusively for Mscaler and Blu MkII but I’ll see what I can find out. Is single BNC operation stable? "

"OK, I’ll need to see what we can test here. As stated, we only design the DBNC function to work with other Chord devices so it may come down to what we can and can’t find out from PS Audio.
All the best "

"I have been speaking with the engineering team. Unfortunately we cannot guarantee or verify compatibility between our own product and the PS Audio transport. We do not have access to the relevant information in order to diagnose or further understand what may be causing the ‘hiccups’ described. We also cannot make amendments to the way our own product works in order to remedy this without jeopardising our own internal product compatibility.
I’m sorry we cannot be of more assistance in this case. "

Thanks for keeping us posted with what Chord has written you. It may very well be the case that there is an incompatibility between the PST and the Chord.

Anything that can be done to make them compatible in a future PST firmware update? :thinking: :pleading_face:

Certainly possible. My guess is it would require some kind of collab with Chord to work smoothly.

I replied in the other thread… Is this question still open / important for someone? I can test here as I have access to a TT2. LMK.

Thanks for checking. It has been established that the dual BNC output of the PST is not compatible with the dual BNC input on the MScaler. I ended up buying the PST so I experimented myself.
Edit: @treva also posted in this thread that he had a similar experience with the TT2 and the PST.

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ah. c’est la vie. Boo.

This multitude of competing formats for high-res digital signal transmission is not helping anyone.

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Dual-AES (whether on XLR or BNC interfaces) is an international standard specified in AES3-2009 (re-ratified in 2019), also known as IEC 60958.

dCS was probably the first vendor to implement dual-AES as they were in fact instrumental in developing the standard in the early 2000s.

Chord’s implementation is also based on the standard and is fully compatible with dCS’ implementation. So, you can connect a dCS Network Bridge or Upsampler to a Chord DAC for example and it works.

If the PST does not work with Chord M Scaler, it’s likely PS-Audio needs to double check it’s compliance to the AES3-2009 specifications.

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Regarding M-Scaler, I think Chord are misleading people in that they say the M-Scaler can be used to upgrade their dacs such as TT2. However, their dacs understand DSD whereas M-Scaler only understands PCM (via S/PDIF (by which I mean Coax, BNC or Optical) or USB). I have an M-Scaler and hoped that the PST would output 88.2/24 when playing an SACD in the same way that the DMP did however that’s not the case. I therefore did not buy a PST.

[update Saturday 4 December 2021 - I intend to email Chord support in the UK and they definitely talk directly to Rob Watts. I’m concerned that what I wrote might be wrong]


Mscaler will accept DSD as an input but it will convert it to PCM before scaling. This is not too different to TT2 (and the rest of the DACs) which will convert to PCM before decoding.

I doubt that I’ll be able to test this myself.

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