Buffalo32S DAC

[Nebby]

Russ posted that the counterpoint measured worse than the IVY. I'll try to find out where he said that, but I'll link it when I find it.

[Nebby]

diyAudio Forums - ESS Sabre Buffalo DAC - Page 61

Counterpoint does "sound" subjectively excellent to me. But measurement shows that the noise floor is about 8db higher and the THD similarly higher.

Now I actually feel pretty good about this is it is better than I had hoped. And if you blindfolded me and asked me which I were listening to, I doubt I could tell you. So at least its not really "worse".

Counterpoint is also just pretty big. Pretty much the same size as the entire new Buffalo32S PCB. Not that this is a key consideration. Just throwing it out there.

I am not very good at subjective lingo.

Hopefully some of you will try Counterpoint out soon and give me your opinion.

Cheers!

Russ

[bdonegan]

Does Twisted Pear use separate analog and digital ground planes? It's hard to tell if they do. From the schematics of the Opus and original Buffalo it looks like the digital and analog grounds are shared?

This should answer that...

[AlanY]

It turns out that ESS has a document with useful suggestions for laying out ground planes:

http://esstech.com/PDF/Application_Note_Component_Selection_and_PCB_Layout.pdf

Like the references Pars posted earlier, they recommend against a split ground plane.

[manaox2]

ESS has experimented with DAC evaluation PCBs ground planes to determine any benefit of split plane grounds for analog and digital ground. It is our finding and recommendation to use only one ground plane for both digital and analog grounds as it simplifies layout and provides no performance degradation. The most important for DAC performance is the ground plane, it should be as solid as possible with as few traces routed through the ground plane as possible. Any traces that are routed through the ground plane and block the “line of sight” from the DAC output to the opamp output stage significantly degrades the output THD.

Here is what it said, looks like they want you to share the ground between them. Now I wonder what I should do if I put my OPUS and Buffalo in the same enclosure and share the ground which is what I plan to do. Would that cause a ground loop? Hoping that a single star ground will be fine.

[n_maher]

This just in...

- At 8PM (20:00) Friday April 17th (Eastern Standard Time) I will enable pre-orders of half of the available DACs.

- The second half will go on sale 12 hours later, on Saturday morning at 8AM (0800).

[naamanf]

This just in...

I know. Oh what to do?

It is pretty pricey and if it wasn't for my curiosity on how it might be better than the current one I wouldn't even consider it.

Anyone want one built?

[morphsci]

I know. Oh what to do?

It is pretty pricey and if it wasn't for my curiosity on how it might be better than the current one I wouldn't even consider it.

Anyone want one built?

Well I am definitely ordering one. I haven't built anything in a long, long, long, ......, long time so I may be getting in contact after I have it in hand.

On a related note: Does anyone see any problem with using an Oppo 980 as a transport for DSD data?

Edited April 16, 2009 by morphsci

[naamanf]

Well I am definitely ordering one. I haven't built anything in a long, long, long, ......, long time so I may be getting in contact after I have it in hand.

No problem. The hardest part is probably soldering up the power supplies and drilling holes.

[Dreadhead]

On a related note: Does anyone see any problem with using an Oppo 980 as a transport for DSD data?

How are you going to get it from HDMI to the DAC? I think the HDMI needs a receiver chip at the other side but I could be wrong.

[Dreadhead]

I know. Oh what to do?

It is pretty pricey and if it wasn't for my curiosity on how it might be better than the current one I wouldn't even consider it.

Anyone want one built?

I'm pretty interested... how much?

[Nebby]

I must finish building my counterpoints so I can hear how the current one sounds first before contemplating the new one. Must....resist...

[morphsci]

How are you going to get it from HDMI to the DAC? I think the HDMI needs a receiver chip at the other side but I could be wrong.

Hmmm, not as far as I know. But then again, that's not very far.

[manaox2]

Hmmm, not as far as I know. But then again, that's not very far.

If you hear of a way to get the DSD digital data off of HDMI to i2s, I would be very interested.

[Dreadhead]

Hmmm, not as far as I know. But then again, that's not very far.

not looking too promising: HDMI - Wikipedia, the free encyclopedia

To get it into a usable format I have an HDFury2 but this looks a whole lot better:

http://www.smartvm.com/HDMI-3-in-1-Converter-Switcher-DVI-YPbPr-RGB-HDMI-v-13-+-SPDIF-LF-Audio-P41522.htm

Maybe I should sell the HDFury2 on Ebay and get one of those since I won't use it for anything but audio

Edited April 17, 2009 by Dreadhead

[Dusty Chalk]

On a related note: Does anyone see any problem with using an Oppo 980 as a transport for DSD data?

Unhacked? Yes, I see problems. Most of the information here is correct.

There are a couple of proprietary interfaces, but most of them are from the same company:

Pioneer player -> Pioneer receiver

Denon player -> Denon receiver

dCS transport ( -> dCS upconverter ) -> dCS DAC

Those are the only ones I know of.

MSB has hacked digital outs of players for their proprietary network-based transport/DAC combinations, but that's all PCM. I'm sure there's someone doing it for DSD, but I haven't heard of it yet. It's probably on the down-low.

[Dreadhead]

It's probably on the down-low.

Oppo does output DSD across the HDMI (1.3) but not too many receivers take the data.

I'm not sure what anyone would do with the DSD stream anyway though since very few DAC can take it in.

[morphsci]

But the Buffalo32S can accept DSD data directly, but it is unclear if the HDCP needs to be stripped off. If it does, then I think the HDFury2 can be employed.

[Dreadhead]

But the Buffalo32S can accept DSD data directly.

True but you need something to get it out of the HDMI which is part of the problem.

Also I would put money that the DAC then just converts the DSD to PCM for conversion anyway. You're not going to get those noise numbers for a DSD DAC. Just get a HDFury2 or the box above and you can just use SPIDIF into anything.

Edited April 17, 2009 by Dreadhead

[Nebby]

I do believe that you can get DSD out of a denon 1920, or a model something like that. Oppo-wise I don't remember any way to get DSD out.

[Dusty Chalk]

... DSD across the HDMI (1.3) ... not too many receivers take the data.

Exactly. Which is why I left it off of this list.

I believe the Sony that's being discussed in the other thread (XA5400S) also does DSD across HDMI.

As to whether or not it does "indigenous" DSD, the product sheet doesn't say. It hints at it (that it does), in the block flow diagram, but the fact that it does the jitter reduction and "hyperstream DAC" after that would indicate to me that you are correct. It could be just shorthand (for two different streams handled similarly), and heck, it might even be a more DSD-type DAC than a PCM-type DAC. Unlikely, though. Hard to tell. Will have to do more research.

EDIT: Well, no, it also says right in the product sheet that the Hyperstream DAC is a 32 bit DAC, so you're right, it's converting it to PCM. So I agree with your conclusion -- that trying to keep the DSD stream as DSD is an exercise in futility.

Edited April 17, 2009 by Dusty Chalk

[AlanY]

Also I would put money that the DAC then just converts the DSD to PCM for conversion anyway.

Not sure why they'd do this since it's a sigma-delta DAC and could handle DSD directly. But the white paper on the Sabre design doesn't say for sure.

[Dusty Chalk]

Not sure why they'd do this since it's a sigma-delta DAC and could handle DSD directly.

Because Sony charges too much to do native DSD? I'm not sure if this applies to DAC chips.

But the white paper on the Sabre design doesn't say for sure.

Except that it says that the Hyperstream DAC is a 32-bit DAC, which pretty much tells me that they're converting it to PCM. Don't you think? (Not being sarcastic, honest question.)

[AlanY]

EDIT: Well, no, it also says right in the product sheet that the Hyperstream DAC is a 32 bit DAC, so you're right, it's converting it to PCM. So I agree with your conclusion -- that trying to keep the DSD stream as DSD is an exercise in futility.

That 32-bit thing doesn't mean anything. It just means it can accept 32-bit input words. The PCM datapath is actually 48-bits wide, which is sweet (volume control can be done digitally with no harm to the signal), but the PCM datapath is really irrelevant for DSD conversion. The actual modulator is a fifth-order sigma delta unit.

Usually manufacturers are clear if they convert DSD to PCM (e.g. the WM8741 datasheet is clear that it's optional), but the Sabre datasheet is pretty skimpy. The Twisted Pear guys might know for sure, since they have access to someone inside ESS.

[Dusty Chalk]

I give up. I just wrote them and asked.

(This does not preclude someone else asking on one of the Twisted Pear threads.)