PCM alternatives for Vivaldi DAC

I recently purchased a used Vivaldi DAC w/ the latest software versions. Using it w/ Scarlatti transport & Puccini clock.

The dealer I got it from suggested SDIF (not SPDIF) as best sonics for Redbook CDs. I’m curious to know what people’s experience has been between 1) upsampling to DSD via dual AES; 2) SPDIF; 3) SDIF.

Thx ahead of time for any insights.


Your dealer is right in theory but but whether or not there is a significant improvement that is audible to you is impossible to say.

Likewise whether transcoding PCM to DSD is an improvement . Some will write that it wonderful. I find it unpleasant. The point I am making is that we all have our individual priorities which we may not even have intellectualised. What these may be person to person is unpredictable.

You can only know if SDIF or upsampling of any type is right for you is by trying it. After all you have the equipment.


I agree with Pete, it’s quite subjective on what sounds the best. Like Pete, I don’t typically like to transcode formats, and tend to keep them in their native form.


I hear some positive impacts transcoding to DSD and some negative. To my mind DSD sounds smoother, which is pleasant. On the other hand, it seems to lose the impact of transients. As Pete and Anup say, it’s subjective. I’d choose the approach you like the most :slight_smile:

I know nothing about SDIF, but dual AES should sound better than S/PDIF. Again, I have to agree, whether you can hear the difference may depend on what other equipment you have in your system.

Interested to hear what you think, if you try the different options out.

As I see it ,SDIF-2 is the best sound quality interface of the dCS products ,which can be used with SDIF-2 output products. Such as Vivaldi transport, dCS Scarlatti Upsampler,dCS Network bridge and your Scarlatti transport.

SDIF-2 was originally developed by Sony to transfer DSD. It uses uses 3 (BNC-) Coax for Left, Right and Clock. SDIF-3 just uses 2 (BNC-) Coax (no separate clock).
SDIF-2 / SDIF-3 PCM is limited to 96kHz.
More recent dCS equipment offers single AES for up to 192kHz PCM and dual AES for PCM from 88kHz up to DSD.
In my system I use a professional dCS 974 for upsampling to DSD. The only possible connection to my Vivaldi DAC for DSD is SDIF-2 / SDIF-3.

AFAIK the Scarlatti transport requires either Firewire or dual AES for SACD (DSD).

Thx all – interesting insights/POVs. I haven’t had time until the weekend to A/B (actually A/B/C) the formats. So far my ears tell me the DSD transcoding creates a sense of more space/air/presence, but one that doesn’t sound quite natural. Between SDIF and SPDIF I don’t know. Thus far leaning 51/49 towards SDIF.

OTOH, my spy at dCS (I can’t reveal my sources :wink: ) tells me, well, we dropped SDIF going forward, for reasons.

From just reading around, I gather single AES would be best for PCM. I thought I could “fool” the VDC by

  1. setting AES to auto
  2. switching to a non-AES input
  3. unhooking AES2 on the STT, then
  4. switching back to AES on the DAC
    The VDC should then say to itself, “ah ha, there’s only 1 AES cable, so I’ll switch to single AES.” Didn’t work: the DAC continues to be on dual AES and there’s just a hissing sound. Dunno, perhaps if I put it in sleep mode or even power off. Of course I want to be sure not to damage it! (STT has only 2 AES outputs unfortunately.) I play far more CDs than SACDs, and this approach, if it worked, involves minimal fiddling.

Sorry but I am a bit confused.In your initial posting you said that:

How then are you accomplishing transcoding?

Auto synching switches according to the incoming data. I am unsure that it will function with one of the AES cables missing as it expects 2 cables. I think you would need to choose manual switching for a single AES cable, though you could use S/Pdif instead. In any case as the Vivaldi DAC does not have IEEE1394 inputs you will need two AES cables to play those few SACDs anyway ( NB: with Vivaldi Mode engaged - you should have firmware v.1.11 installed).


Maybe I’m misunderstanding, but if I play PCM via dual AES, isn’t that transcoding to DSD? The DAC does say “DSD” on the display.

Beyond that, my only interest in single AES is if the sonics are better than other PCM choices. But it sounds like there’s no easy way to switch btwn single AES for CDs & dual for SACDs. Barring an SQ advantage the point is moot.

Informationally, the STT is at v 1.11 & Vivaldi mode is enabled.

Cheers, J

No. To transcode PCM to DSD requires a device that will do this , commonly this is an upsampler or more recent dCS transports which are also able to convert formats. DSD and PCM are different ways of storing digital information , one ( PCM) being based around varying bit depths and sampliing frequencies, ( normally from 16 bits to 24 bits and from 16.41 KS/s to 352. 8KS/s so that offers more flexibility than just redbook). The other ( DSD) uses a single bit but very high sampling rates ( called DSD 64 up to DSD 512 with DSD128 being the limit of current dCS equipment.). Transcoding means changing the coding from one format to the other format.

Your current equipment cannot upsample or transcode and is limited to 16/44.1 PCM ( redbook) and DSD64 which is the rate from SACD. Incidentally the Vivaldi DAC will process all of the above up to DSD128 but your source equipment is the limitation in this respect.

OK, now I’m confused. I get what you’re saying re SACDs: the STT is sending DSD64 to the VDC. But why when I select dual AES for a redbook CD does the DAC still say DSD rather than 16/44.1?

(And of course when I use SPDIF it does say 16/44.1.)

Good question.

After a fair bit of research ( it is many years since I owned a dCS transport of this generation) I think I have an answer.

It looks like that when Vivaldi Mode was added when firmware 1.11 was installed it may have added not only the ability to connect with dual AES instead of IEEE 1394 but also the ability to upsample CD to DSD (when AES was selected). Or maybe the feature was there but kept obscure. News to me. Anyway dCS now call their current transports Upsampling Transports.You’ll also find reference to it in the later versions of the User Manual p.12.

So it may be that to play CDs natively using dual AES one needs to deselect Vivaldi Mode.

Interesting. My instinct is that the Vivaldi knows what kind of signal it’s receiving, so upsampling is going on. But perhaps not.

I’ll also try turning off Vivaldi mode, although I thought w/out Vivaldi mode dual AES wasn’t possible. Easy enough to find out.

thx, Jeff

Jeff, yes, you are right. This is why meant that your question was good because Vivaldi DAC does indeed report what it is receiving. So I needed to work out how CD in native form could then be replayed.

It now seems is that Vivaldi Mode means that the older Scarlatti and Paganini transports behave just like newer models which are described by dCS as upsampling transports. See page 12 of the user manual ( I assume that you have this but if not let me know). See also page 16 where we learn that by switching off Vivaldi mode the two cables carry identical streams of 16/44.1. So that is one way how CD is played in native format.

An alternative method to switching off Vivaldi mode would be to keep dual AES for SACD play and switch to S/Pdif DAC input ( another cable) for native CD replay. That is what I do with my Rossini Transport as I cannot get on with transcoding or any form of upsampling ( just me). BTW the data transmitted by single AES or S/Pdif is the same , they conform to AES3 protocol.


Thanks. This tracks what I’m seeing/hearing. I turned off Vivaldi mode: AES1 and AES2 are then recognized by the DAC as discrete inputs, each being 16/44.1.

So between AES1, SPDIF, and SDIF, my question will be SQ. The difference between the latter two was audible, albeit not huge. Certainly not a difference you had to strain to hear. In theory I guess AES1 should be best. But as you point out, you just have to listen.

AES1 & 2 should obviously be identical.


Hi Guys,

Just to throw in a little clarification here if I may…?

When using the Scarlatti Transport in Vivaldi mode, AES1+2 are always an encrypted DoP DSD64 stream, irrespective of disc type.

In this mode CD playback is upsampled to DSD whereas SACD playback is output via AES1+2 as native DSD.

SPDIF1-3 and SDIF are always 44.1kHz / 16bit PCM, irrespective of disc type, so CD is output as-is and SACD is converted to PCM on those outputs.

If you are using a Vivaldi Transport then the Vivaldi transport has an additional digital audio output - AES3 - which is the same as the SPDIFs, and Easyplay automatically switches inputs on the DAC. Easyplay cannot be used however if you mix product ranges (i.e. Easyplay doesn’t work if you use a Scarlatti Transport into a Vivaldi DAC).


Super-useful, Phil – thx.