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Review and Measurements of Okto DAC8 8Ch DAC & Amp

Dacapalooza

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Question 2: Should I use the Trinnov for volume since it already doing volumey stuff like EQing and BM. Or does the dac8 have more scientifically correct volume tech? But than I am mixing volume tech.
 

Dacapalooza

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Trinnov Demon is a room correction device made in France. Statistically people prefer room correction subjectively. A science to subjectivity. It’s ironic like rain on your wedding day.

As for what the Vanity is. I am still learning. I thought I knew. But upon finding this sight today...

What I got so far:

Short answer: Blu Ray and HDMI 4K to AES converter.

It also is a Dolby Digital/DTS re-clocker.

I cringe at that as well.

I guess Vanity designers did not know how perfect that grey Oppo ribbon is. Their goal was to isolate the playing BD or the evil HDMI from DACs. So they put the audio signal in a buffer then resends and reclocks much like the 2 reviewed here. Unlike them, the vanity has the complex circuitry to resend the original rate and does not need a new power supply to introduce AC evilness. Also, unlike them it is AES. The ASR reviewer seem to mention that some evil reclocking signal should go to a ground wire when reclocking which AES has. Boy am I glad I got the clones psu as it has a ground connection so all the upto the power supply is grounded. So maybe that helps? I got it because I thought it was hilarious and impressive that clones geeked out for an AV device and made a second version of a psu so finally caved in and became a full blown Oppo modder.

I got the 203’s in 17. My dealer knew of my vanity 103 so he convinced me to buy two even though I was not 4K. Although I am sad to learn all he got was 2 cups of tea. He should be rewarded more. My projector broke last April so got the JVC NX5 and 2 Vanities and the psu.

In the history of time this one of two devices that converts Dolby to AES. The first was Tact.
This is one 3 devices that reclocks Dolby. The first was Camelot Dragon 5.1 that did not use a buffer and Theta Jitter Jail reclocks.
This is one of 2 devices that converts HDMI to AES. Arvus, but it is not Dolby compatible.

On the otherhand, the oppo grey ribbon test performed in ASR did not have a 4K Blu-ray playing while connected to 4K projector and the analog connected to amp at least the channels not being tested.

My grandfather told me if someone you trust [in a subject matter] does more than you ask you should thank him. Even your mechanic and even if it costs.

I trust Vanity designers. I corresponded with them. Besides I don’t get the impression they are doing it for the money. They truly want to help humanity. These are BD we bought with our money we have to put up with a lot of crap to make. The vanity designers feel we should be able to play a BD any way we want. No one should tell us how a blu ray we legally own must be played.

Especially because ASR is saying the AV people can’t bother giving us $99 tech.

After all that work that Hollywood puts in. It’s inhumane and torturous almost.

ASR is saying AV devices can’t clear 16 bits when BD is 24.

You can’t stop the signal, Mal
 
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Nick Laslett

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Question 2: Should I use the Trinnov for volume since it already doing volumey stuff like EQing and BM. Or does the dac8 have more scientifically correct volume tech? But than I am mixing volume tech.

I found this thread had useful feedback on this topic.
https://www.audiosciencereview.com/...ttenuation-before-power-amp.5844/#post-131431

There is an ESS presentation on the topic of DAC volume control, also a Youtube from RMAF11

@bennetng makes the point that it is best if you can do the attenuation in software with 32bit or 64bit floating point calculations.

He goes into much more detail in his guest post on Archimago’s blog.

http://archimago.blogspot.com/2019/06/guest-post-why-we-should-use-software.html

Unfortunately I could not get my MiniDSP NanoAVR to pass his mp3 test, neither would iTunes.

You have a great setup, if the VanityHD was still available I would go with an Oppo 203 to DSP to OktoDAC8 for my signal path. MiniDSP do an alternative to the Trinnov for DSP, the all digital DDRC-88D with Dirac and Bass Management.
 
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Kal Rubinson

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Trinnov Demon is a room correction device made in France. Statistically people prefer room correction subjectively. A science to subjectivity. It’s ironic like rain on your wedding day.
Ain't it the Trinnov D-Mon?
 

Dacapalooza

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Ain't it the Trinnov D-Mon?
The - must be French for e.

When I spoke with Trinnov they refer to it as the Demon. I’ve seen YouTube videos and I’m sure I hear Demon. I’d make a horrible spy I’m not great with zip lining and swapping out circuit boards at the same time nor am I great at understanding what I perceive in my egotistical shallowness as an accent so you might be right.
Or maybe D-nial IS just a river in Egypt. Although my wife thinks D-nile is my Brooklyn accent.
 

sahihe

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Given two of three modes, Pure USB and USB / AES, as described on that page are using the USB, I would say mostly yes to your comment above. However, the Pure AES mode expressly states that "it does use the recovered AES/EBU clock for processing the received audio data."

Here's what's throwing me off... From the section regarding USB/AES mode -

"USB / AES is a unique mode of operation that does use the master clock recovered from the 1st AES/EBU to set the pace of the audio data transfer from the USB host."

Sounds like, in this hybrid mode, the clock is being recovered from AES source and is being used to drive the data to the PC, where it is picked up by the driver and convolver and then pushed back out to the dac on the output USB channel. That output from PC to the DAC over USB is presumably asynchronous? It's not clear to me.
 
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Kal Rubinson

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When I spoke with Trinnov they refer to it as the Demon. I’ve seen YouTube videos and I’m sure I hear Demon.
I'm sure that they sound the same.
 
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Hifihedgehog

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Sounds like, in this hybrid mode, the clock is being recovered from AES source and is being used to drive the data to the PC, where it is picked up by the driver and convolver and then pushed back out to the dac on the output USB channel. That output from PC to the DAC over USB is presumably asynchronous? It's not clear to me.
For this hybrid mode, my gut tells me the DAC is asynchronous whereas the PC is synchronous due to this unique signal path:
AES -> USB Host (Input) -> PC
PC -> USB Host (Output) -> DAC

What is happening here is the DAC is both outputting the AES signal via USB to the PC and simultaneously receiving a USB audio input from the PC. As far as I can tell, those two processes are independent from one another.

With the DAC's output stage, the clock from the AES is being fed to the PC and PC's job is to stay in sync with the AES input's clock that is being looped into the PC via USB. The manual states that in order to get any input, the caveat is you have to ensure you set your PC's input sampling rate to match the AES input's sampling rate. So the PC is synchronous with the AES input.

Meanwhile, with its input stage, the only source that is visible to the DAC is the USB audio which means the DAC drives the clock, not vice versa. Once the PC receives the AES input, it can be processed, recorded, and/or sent back in whatever form you wish to the DAC presumably with any supported sampling rate. That is because the DAC input is insulated from the AES by the PC. For all intents and purposes, you could send white noise back to the DAC while recording the AES input via USB and the DAC wouldn't be the wiser. So the DAC is asynchronous.

---

By the way, that would mean the DAC8 Pro would be an ideal (if not the ideal) candidate for studio and broadcast. Link up all your microphone and instrument inputs at your AES interface, link into the DAC8 Pro via AES, watch the DAC8 Pro send it via USB into your workstation for processing and recording, and then your PC sends it back to the DAC for playback in whatever form you want. The applications extend far beyond mere room and crossover calibrations.

For example, if you were running a studio, you could even set up a reference quality headphone station for your artists/producers/sound engineers with 4 independent stereo pairs linking up to 4 separate headphone amplifiers (the best candidate here would be the Geshelli Labs Archel2.5 Pro, which features XLR inputs). The artist(s) could hear the individual track, the producer(s) could hear the complete track, and the sound engineer(s) could hear whatever combination of elements they want.

Judging by these features in addition to the already world-leading measured performance, the DAC8 Pro is highly underrated as not only the definitive multichannel DAC in the audiophile market but a largely undiscovered giant killer in the pro audio market.
 
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sahihe

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For this hybrid mode, my gut tells me the DAC is asynchronous whereas the PC is synchronous due to this unique signal path:
AES -> USB Host (Input) -> PC
PC -> USB Host (Output) -> DAC

What is happening here is the DAC is both outputting the AES signal via USB to the PC and simultaneously receiving a USB audio input from the PC. As far as I can tell, those two processes are independent from one another.

With the DAC's output stage, the clock from the AES is being fed to the PC and PC's job is to stay in sync with the AES input's clock that is being looped into the PC via USB. The manual states that in order to get any input, the caveat is you have to ensure you set your PC's input sampling rate to match the AES input's sampling rate. So the PC is synchronous with the AES input.

Meanwhile, with its input stage, the only source that is visible to the DAC is the USB audio which means the DAC drives the clock, not vice versa. Once the PC receives the AES input, it can be processed, recorded, and/or sent back in whatever form you wish to the DAC presumably with any supported sampling rate. That is because the DAC input is insulated from the AES by the PC. For all intents and purposes, you could send white noise back to the DAC while recording the AES input via USB and the DAC wouldn't be the wiser. So the DAC is asynchronous.

Thanks for the detailed answer, Hifihedgehog. I think I am getting it now. This separation between the input and output paths opens up a lot of possibilities and use cases, as you've captured.

For my use case of wanting to feed it TOSlink output from Chromecast audio as my streamer, the two remaining issues would be
1. converting toslink to AES. Something like Hosa ODL312 should work.
2. sample rate conversion of the audio stream coming out of Chromecast, to be able to play music being streamed at different sample rates. Since the PC has to match this sampling rate, I would probably need a way to upsample everything to a fixed rate and then set PC to match that. Any suggestions for products that would do this?

Thanks
 
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Dacapalooza

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I found this thread had useful feedback on this topic...
If I understand correctly, dac8 does not have good volume tech. I will use the Trinnov volume. Thanks.

if the VanityHD was still available
Thanks for letting me know. I was thinking of buying a 3rd one so you saved my time in my thoughts. I only just found out Oppo went out of business. DVD still out sells BD plus streaming I guess. Now I really feel bad that my dealer only got 2 cups of tea for the sale. Most my friends/guests actually make fun that I still use physical media.

Also you should contact JVB, if they get enough people interested they may make another batch?

It's way more fun to make audio upgrade every 5 years. Analyze what changed. Better than a movie even. That is why I never find out the gender to my kids before they are born. Adds to the quality when it is a surprise.

I was about to buy 3 Brooklyns because I thought it would look so cool. My dealer was actually giving me a hard time selling it to me saying the Trinnovs have great DAC's and I'll never hear the diff especially in AV. He did not even sell me the Demon. I don't know if I can hear a diff in high-end vs not and if I did it is probably griping at hairs. I have always owned high-end though. My goal is to have the most advanced AV system that humanity has to offer within the limitations of my room and budget.

I did a last Google on new multi ch DAC tech and ASR came up first. So Google did its job. When did this forum start? Was around in 16?
Anyway I feel I owe a beer to the forum starter. Saved me $5K. Or do I owe it to Google, maybe?
 

maxidcx

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Hi Guys, you are right about the complex treatment of the signal in the different clock domain between the dac8pro, AES inputs, ESS dac and usb host. to try to make it simple (...) :

the ESS DAC has its own local clean clock (45/49mhz). This is the best choice for the supported sampling frequencies.

In Pure USB mode this clock is also routed to the XMOS and is the master clock for all USB exchange:
The exact clock rate is measured (in comparaison with the USB 8khz frame sof) and this is sent back to the usb host driver (via so called feedback endpoint) . Then the Usb Host driver will adjust its streaming rate (in and out) according to this feedback.
Of course the XMOS will buffer (in an out) so that there is no sample drops during automatic adjustments.
(as an example at 44100hz, the xmos receives either 5 or 6 samples per usb frames every 125us)
So the USB host is asynchronous to the XMOS, BUT due to the feedback given and the driver auto adjustement and buffering, then the USB host data stream at the output of the XMOS (I2S or DSD) is synchronous to the ESS DAC master clock !

Also we have made different tests on the ESS Sabre configured in sync and async mode.
At the moment, the ESS is configured in Asynchronous mode BUT behaves fully synchronous with the XMOS I2S/DSD data, and its DPLL is passthrough defacto.

in USB/AES mode, this is a bit different : XMOS master clock is coming from the AES receiver recovered clock, and the ESS DAC is still clocked with its precise 45/49mhz.
So the data stream (in and out) between the Usb host and the XMOS is still asynchronous BUT synchronous to the AES signal (due to same feedback/buffer mechanism).
The XMOS data (I2S) going to the ESS Dac (coming from the Usb host) is asynchronous with the ESS DAC and here we benefit from the great DPLL and jitter-killer embedded in the ESS Dac.

this was a choice to not have any ASRC between AES and USB host application, so it is true that the Usb host sampling frequency has to be manually selected to cope with the incoming AES rate (otherwise silence is transmitted in and out).
this is a great solution for Pro audio as the product has a clear and "pure" behavior.
 

maxidcx

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hi sahihe, you could consider finding a MiniDSP miniDigi as a diy TOSLINKs - spdif(coax) interface integrating an ASRC, but its not anymore sold so a second hand product is required, or you can go with minidsp nanoDigi8 B which is still on the catalog at a fair price. it natively convert and works at 96k. this would also give you some possibility to test cross over outside the PC
 

beefkabob

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A 32-bit volume control and an ultra fine preamp are both going to be beyond what you can discern.
 

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sahihe

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Thanks maxidcx for the detailed description of the three modes. Much appreciated.

this was a choice to not have any ASRC between AES and USB host application, so it is true that the Usb host sampling frequency has to be manually selected to cope with the incoming AES rate (otherwise silence is transmitted in and out).
I'm still digesting it all, but where is this Usb host sampling frequency specified? I didn't see it in the menu section in the manual.

hi sahihe, you could consider finding a MiniDSP miniDigi as a diy TOSLINKs - spdif(coax) interface integrating an ASRC, but its not anymore sold so a second hand product is required, or you can go with minidsp nanoDigi8 B which is still on the catalog at a fair price. it natively convert and works at 96k. this would also give you some possibility to test cross over outside the PC
Cool, I'll check these out. Thx.
 

Snafu

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If i use Okto Stereo with spdif from blu ray-player, how much delay Okto adds ?

cheers
 
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