Review and Measurements of Okto DAC8 8Ch DAC & Amp

[Neddy]

Well, there is this:
http://www.arvus.io/hdmi-2a.html
No idea if they are actually available, and haven't found any that have shown up pre-owned, and screechingly pricey anyway.
Thanks for the reminder about the few ADC tests here...though not directly relevant.
I've done some digging through the various pro forums and can't find any useful tests, and even not that much in the way of 'reg'lar opinion reviews. That 'home pro' market might be pretty large nowadays that everyone has a 'band' and aims to be YT or Bandcamp masters (Wouldn't it be wonderful...)
I'm hesitant to throw more hardware and (probably 'cheaply developed') software at this problem, though the 'zon return policy makes it easy to 'back out of' at least. Amazing (thank you hollywood) that this far into HDMI, I have to be sharpening my pencil (and brain) between building a 8PDT switch box (!!!) or a gob of new hardware/software!
I'm running a NUC, and totally unfamiliar with Firewire, so haven't really looked into it beyond thinking it'd require a converter card (more hardware, etc!)...otherwise...duly noted!
And, yes, I'm very happy that, for music at least, the future is pretty darn 'simple' and, with this DAC, solved for me. (Pending actual receipt).
Thanks much!!

 

[PA3BPAT]

PA3BPAT replied:
Which is pretty much standard option for decent AVRs modern days.

This is sadly not the case that one would expect. Rather few AV Receivers actually do play native DSD without PCM conversion.

It is hard to check what they really do, but in a price range 0.5-2x from the price of Okto DAC8 PRO most of modern (2017-) AVRs at least claim doing so.


While checking this claim today, I actually found one device which have specifications close to what I am looking for (HDMI to multichannel XLR balanced audio outputs supporting DSD up to 11.2MHz direct). Well, it is twice as expensive as Okto DAC8 PRO, trice as big, ~10 times heavier, equipped with noisier DAC chip (so, perhaps, never breaks any records here), have a bunch of bells and whistles I would never need, but it exists. Which is certainly a proof that the demand is there. Yamaha CX-A5200 is the name.

Just wonder, shall I wait for Okto DAC8 PRO to implement HDMI-in or just go for it...))

 

[g29]

December Bump.

Has anyone in North America received their production DAC8 PRO yet or have been given a firm delivery date yet ?

If so, please chime in.

 

[RUR]

Pavel advised last week that my unit would ship today. Hopefully, I'll have a waybill # by COB.

 

[ernestcarl]

.. audio outputs supporting DSD up to 11.2MHz direct ...

Those megahertz sure look impressive, but I still do not see what is the point of it. What are the actual psychoacoustic benefits of said extreme DSD formats?

 

[Spocko]

No one is opposed to impressions here. Heck any impressions are better than none when people want to know more about a product. It doesn't always have to be about the totality of ever sonic quality under the sun. The main problem arises when people want to talk about aspects that fly in the face of observable fact. Saying the imaging is great, and the device produces clear, clean, detailed sound isn't contentious and people can extrapolate what you mean when you say this - no one rational expects a THD measurement from you to take you at your word. But if one were to say "the warmth and auditory alacrity and veracity of the laterally forward presentation is very liberating" ..that's the sort of stuff that gets people to roll their eyes because no one knows what that could possibly mean.

Thanks for the impressions :]

You mean, the DAC didn't lift a veil and suddenly the hummingbird can now be heard flying by the trombone player?

 

[Spocko]

Those megahertz sure look impressive, but I still do not see what is the point of it. What are the actual psychoacoustic benefits of said extreme DSD formats?

For people like me over 40 who's been to one too many rock concerts and nightclubs? ABSOLUTELY NOTHING

 

[pma]

Those megahertz sure look impressive, but I still do not see what is the point of it. What are the actual psychoacoustic benefits of said extreme DSD formats?

Do not forget that DSD is a 1bit (bitstream) format so you need much more BW for transmission. Minimum is 65536 x 44.1kHz = 2.89MHz (oops...) 64 x 44.1kHz = 2.82MHz per channel. To get resolution of 20bits or even 24bits PCM at high frequencies, you need to use massive noise shaping = high order DSD modulators. And 11.2MHz of bitstream gives you better resolution at the top of audio band because noise shaping may be shifted to higher frequencies and lower noise bottom.

 

[ernestcarl]

Do not forget that DSD is a 1bit (bitstream) format so you need much more BW for transmission. Minimum is 65536 x 44.1kHz = 2.89MHz per channel. To get resolution of 20bits or even 24bits PCM at high frequencies, you need to use massive noise shaping = high order DSD modulators. And 11.2MHz of bitstream gives you better resolution at the top of audio band because noise shaping may be shifted to higher frequencies and lower noise bottom.

Thanks for the reminder. I was already aware of this. What I do still wonder is if there are actually any psychoacoustical studies that prove that DSD formats are rated as superior or more resolving by humans.

 

[Tks]

Do not forget that DSD is a 1bit (bitstream) format so you need much more BW for transmission. Minimum is 65536 x 44.1kHz = 2.89MHz per channel. To get resolution of 20bits or even 24bits PCM at high frequencies, you need to use massive noise shaping = high order DSD modulators. And 11.2MHz of bitstream gives you better resolution at the top of audio band because noise shaping may be shifted to higher frequencies and lower noise bottom.

I'll never understand this concept though. I get it in theory, but not in practice is what I mean. How much more bandwidth is needed to shift said quantity of noise shaping? Is there diminishing returns, is there some sort of scaling of some kind? How much noise is in need of "shaping" for it to not matter with respect to audibility thresholds?

 

[pma]

I'll never understand this concept though. I get it in theory, but not in practice is what I mean. How much more bandwidth is needed to shift said quantity of noise shaping? Is there diminishing returns, is there some sort of scaling of some kind? How much noise is in need of "shaping" for it to not matter with respect to audibility thresholds?

Try this, e.g.

http://sdg-master.com/lesestoff/attachment.pdf

http://www.loc.gov/preservation/digital/formats/fdd/fdd000230.shtml

Courtesy Audiopraise (Pavel V.)

This plot shows 1KHz spectrum for 64Fs DSD (2.82MHz). See very quick loss of dynamic range above 20kHz.

 

[ernestcarl]

Try this, e.g.

http://sdg-master.com/lesestoff/attachment.pdf

http://www.loc.gov/preservation/digital/formats/fdd/fdd000230.shtml

View attachment 41301
Courtesy Audiopraise (Pavel V.)

This plot shows 1KHz spectrum for 64Fs DSD (2.82MHz). See very quick loss of dynamic range above 20kHz.

Thank you!

At any rate...

"The main conclusion drawn from the data collected is that no single format was overwhelmingly chosen as the participantsí preference."

 

[Tks]

Try this, e.g.

http://sdg-master.com/lesestoff/attachment.pdf

http://www.loc.gov/preservation/digital/formats/fdd/fdd000230.shtml

View attachment 41301
Courtesy Audiopraise (Pavel V.)

This plot shows 1KHz spectrum for 64Fs DSD (2.82MHz). See very quick loss of dynamic range above 20kHz.

Still somewhat lost :\ Especially as to how it relates to audibility vs other sample rates in a similar realm.

 

[Kishore]

My unit is delivered - but I am on travel and will be able to hear only next week

December Bump.

Has anyone in North America received their production DAC8 PRO yet or have been given a firm delivery date yet ?

If so, please chime in.

 

[g29]

My unit is delivered - but I am on travel and will be able to hear only next week

Wow, 1st post. Welcome to the forum.

Keep us posted once you get back from travel.

 

[PA3BPAT]

Those megahertz sure look impressive, but I still do not see what is the point of it. What are the actual psychoacoustic benefits of said extreme DSD formats?

There are simpler, more earthy needs for hardware. Some (rare although) files sold as DSD256 only and you have to have some hardware to play it, haven't you? After all, the space on HDDs is cheap.

 

[ernestcarl]

There are simpler, more earthy needs for hardware. Some (rare although) files sold as DSD256 only and you have to have some hardware to play it, haven't you? After all, the space on HDDs is cheap.

The Topping D10 I have here should be able to play it. Not particularly interested in investing in DSD, nope.

 

[wineds]

MIne has arrived. Sounds great.

 

[cjf]

This DAC appears to have promise but I wonder if early text mentioning the possibility of bumping up the output voltage to15.x has been tabled? The current User Manual only mentions 4.1vRMS on the Analog Outputs. For most folks this is probably more than enough but for others doing heavy room corrections..etc its probably very shy of what is needed to make up for the volume loss after corrections depending on various Amplifier gain..etc.

I've got Benchmark DAC3 with -10db "Pad" in place which is said to be about 5.8 vRMS and its just barely enough output to reach a satisfying listening level of about 100db or so in room at chair (it is a big room though FWIW).

This is based on roughly a -20db cut off of the headroom due to Audiolense corrections..etc

Only having 4.1 vRMS is a deal killer for me personally otherwise I might be all over this unit. I also wonder how a big boost in output level would effect the current posted measurements. Would it be just as impressive with say double or triple the output voltage?

 

[1234VICE]

This DAC appears to have promise but I wonder if early text mentioning the possibility of bumping up the output voltage to15.x has been tabled? The current User Manual only mentions 4.1vRMS on the Analog Outputs. For most folks this is probably more than enough but for others doing heavy room corrections..etc its probably very shy of what is needed to make up for the volume loss after corrections depending on various Amplifier gain..etc.

I've got Benchmark DAC3 with -10db "Pad" in place which is said to be about 5.8 vRMS and its just barely enough output to reach a satisfying listening level of about 100db or so in room at chair (it is a big room though FWIW).

This is based on roughly a -20db cut off of the headroom due to Audiolense corrections..etc

Only having 4.1 vRMS is a deal killer for me personally otherwise I might be all over this unit. I also wonder how a big boost in output level would effect the current posted measurements. Would it be just as impressive with say double or triple the output voltage?

(5.8/4.1)^2 = 2

3dB of reduced output is a deal breaker to you? It sounds to me that you need more gain from your amplifier.

Also, +20 dB on your room correction curve is quite agressive IMO. At 100dB at your listening position you would be pushing a lot of power at those frequencies. I dont know what kind of equipment you are using of course.