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Review and Measurements of Okto DAC8 8Ch DAC & Amp

Neddy

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I'm not (yet) well enough versed to answer, but intend to try out the JR DSP Studio for non-main/sub room correction, and will use REW to determine the EQ settings for those.
So I assume it will work? I'm sure others can answer more concretely...
I'm doing main speaker bi-amp and subwoofer crossovers downstream of the Okto...but will also try doing the sub in DSP Studio as well (but the Venu's peak limiters are very handy for use with the sub and LFs when things Get Loud).
Still a few days away from getting everything hooked up....
 

g29

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If my use case is to have a dsp engine to do 7.1 with crossover of 80db on the sub and routing the output via USB to an OCTO 8, could I just use JRiver as my front end with no other software (like rePhase) to provide filters, room and speaker correction, etc? Would that work well using just the "room correction" feature in DSP studio, or are there some limitations in the program that would make that a poor choice? In other words would JRiver plus an Octo 8 add up to a 7.1 Preamp processor all by themselves, or do I need to find a supplemental software to use as a plug in to make that kind of use case work well?

Are you planning on muti-channel audio/video or trying to bi/tri/quad amping audio ?

JRMC can do the latter, but I don't know if it can handle all of the multi-channel movie codecs.

You can make your XO in JRMC and/or RePhase. Rephase will give you more XO options and phase control. There are commercial packages that you can also use.

Having REW will be helpful for AutoEQ. You can make your PEQs in REW and hand enter them into JRMC's PEQ or load them into RePhase and generate convolution files that will then be loaded into JRMC. Hand entering them is slow and gets tedious very quickly.

You can start out with just basic digital XO's in JRMC and then work your way into more advance integration methods over time.

I was able to triamp the prototype with just JRMC in a very short time and then added RePhase to the mix.

See this post for more details on how to make digital XO's in JRMC
 
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Alec_eiffel

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DAC8PRO review

I had the chance to be #1 in the French DAC8PRO tour, here’s my report.

DAC8PRO against OPPO SONICA in stereo

We had one listening session at a friend's place, in comparison with an Oppo Sonica streamer/DAC (around 1000€, so comparable in price and features with the upcoming DAC8 STEREO).
The full report in French is here http://forum-hifi.fr/thread-2327-post-316543.html#pid316543 posted by my friend renan, I am alec_eiffel in this thread.
For non French speakers, in summary, I preferred the DAC8PRO, it was a little more « engaging » than the Oppo.

Not in the report : for 44.1kHz material, software upsampling in Roon to 192kHz linear phase / slow roll-off proved to give a slightly better performance than the DAC8 internal upsampling (which is not a surprise).

Multichannel test

I was very curious about how the DAC8 Pro would behave against my current DAC, Exasound E28 Mkii, fully balanced version. According to reports, the E28 is only marginally behind Exasound’s current flagship E38, retailing at 3500 USD. I bought my E28 last year second hand for 1500€.

Setup is as follows :
- Server PC : Roon Server + HQ Player : Intel Nuc8i3 under Windows 10 + Audiophile Optimizer
- Player PC : IntelNuc5i3 in fanless case, Windows Server 2012, Fidelizer 8.5 + Minorityclean 23, HQPlayer NAA, Exasound ASIO driver
- HDPlex 200 PSU powering PC Player (19V) and Exasound DAC (12V)
- bass1 channels : IMG Stageline 1000D
- bass 2 and highs : ClassDAudio SDS470
- mids : SMSL SA50
- pair of DIY open baffle 4 way speakers. Bass1 20-100Hz and Bass 2 20-220Hz are Eminence Alpha 15A. Mids 200-1500Hz PHL 2520. Highs AMT ESS V1 1500-20000Hz. Photo here : https://community.roonlabs.com/t/fo...o-you-like-about-them/36032/225?u=alec_eiffel
- Roon Server takes care of room correction by HomeAudioFidelity, outputting to HQPlayer for upsampling and 8channel generation @384Hz (Exasound) or @192kHz (DAC8PRO). Upsampling filter is Closed Form 1M. Speaker filters have been designed with Rephase and are minimum phase except for 1500Hz cutoffs which are linear.
- Mostly DIY power, signal and speaker cables

It takes a bit of time to switch between DAC8PRO and E28 with all the cables, so I’ve only tried a couple of songs I know very very well : James Carter/Out of Nowhere, Melanie de Biasio/I am gonna leave you, Youn Sun Nah/Please don’t be sad.

On the Exasound I used HQPlayer DSP volume (DAC at 0dB) as it is much more convenient to adjust volume from Roon interface. For DAC8Pro i used the provided remote or central knob (didn’t want to take the risk of bugs/potentially damaging the system and my ears, with speaker sensitivity close to 100dB/1W/1m...).

Sound level was calibrated with my faithful UMIK-1 under REW.

In conclusion : the try was somehow frustrating :)

The two DACs were really really close. Even on songs I know very well, I could not hear a clear difference. Which means in both cases it was very good. Focusing on all the little details I know, it was impossible for me to isolate a pattern. So at the same time happy and frustrated, I was really not able to segregate the devices... Maybe with more time ? After all, both DACs share the same ESS chip and design philosophy (high end PS, balanced output...) so it makes sense that they « sound » close.

NB : I couldn’t try multichannel DSD as my server is not powerful enough to generate 8 channel DSD. Also the noise floor at OdB was identical with both DACs, which probably means the amplifiers noise dominates.

Drivers

MacOS : DAC is recognized under Coreaudio as expected without driver. It was impossible for me to play DSD. Stereo and multichannel PCM were fine, no clicks and pops. Anyway MacOS is not anymore recommended from my point of view for hifi audio streaming : OS is now too heavy and tough to optimize.

Linux : DietPi works well with both RoonBridge and HQPlayer NAA including DSD64 and 128. Same with Roopeee/Roon Bridge. This is good. Test platform were Allo USBridge and PI3B. There is one shortfall, and potentially a big one for those using DSP volume instead of DAC’s volume : there are occasional and very loud « pops » and « buzz » when changing sampling frequency and/or number of channels. ALSA doesn’t handle channel changes very well, I experienced that already with my DIYinHK multichannel board. Otherwise SQ is fantastic.

/edited/

Windows: i had some issues but finally was able to get all in order. The DAC8Pro deserves a good ASIO driver I hope one will be issued one day.

/end of edits/


Conclusion

The DAC8PRO is a great product. SQ is fantastic on the USB input when given a good source. It is very neutral, engaging. It plays in the same court as the Exasound multichannel players, retailing at 2-3 times the cost. The finish is solid, the HMI with the central rotary knob is very complete and well thought.

What I’d wish :
- in priority a good Windows driver for these in need (not yet available as standard I understand)
- no pops and clicks under Linux in multichannel or at least warn the user
- software controllable hardware volume
- display the number of channels streaming on the screen

Thanks a lot to Pavel for giving me the opportunity to test the DAC8PRO. I would definitely buy it against Exasound it I had to build a new multichannel system!

Good luck to Okto for the launch of the DAC8STEREO which probably has 100 times more market potential than the DAC8PRO - multichannel DAC/preamp are clearly a niche in the hifi market, at least given the small number of active threads on the matter in forums against stereo DACs threads... On the basis of what I heard in stereo with the DAC8PRO, the DAC8STEREO has in my view the potential to become a new reference in the 1000-1500€ price range.

DIsclaimer : I am in no way affiliated to Okto Research, just a passionate hobbyist!
 
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Neddy

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And another - preliminary - report:

I just yesterday got 'first light' from my OktoDAC Pro stereo outputs and can definitely say that the improvements coming from an Emotiva UMC-200 (Oppo 103 hdmi-> Emotiva ->analog) are very noticeable - stunning even.
(So - from, what, 1% THD and maybe 85db SN? to Okto's performance level?)

Interesting that the differences - clarity, much improved HF 'snap', and even channel separation, etc etc - are so obvious I feel there is no need to even try to "A/B" the two setups.

Also, the old (Emo) system I thought sounded 'darn good' - so am very pleased that the upgrade was well worth it.

Thanks for such a wonderful product, Pavel!!

I'll report back in more depth as I get more listening time in and more 'features' enabled; this upgrade entailed a lot of other major changes to the entire system (but not the audio chain downstream of the DAC).

Note: I'm running kind of a 'hybrid' bi-amped stereo/mch system, with the bi-amped stereo mains' crossovers/EQ/Limiters (etc) being implemented downstream of the OktoDAC in a dBX Venu 360 via AES from the OktoDAC, and the surround channels (to be) DSP/EQ'd upstream in JRiver.
 

wineds

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And another - preliminary - report:

I just yesterday got 'first light' from my OktoDAC Pro stereo outputs and can definitely say that the improvements coming from an Emotiva UMC-200 (Oppo 103 hdmi-> Emotiva ->analog) are very noticeable - stunning even.
(So - from, what, 1% THD and maybe 85db SN? to Okto's performance level?)

Interesting that the differences - clarity, much improved HF 'snap', and even channel separation, etc etc - are so obvious I feel there is no need to even try to "A/B" the two setups.

Also, the old (Emo) system I thought sounded 'darn good' - so am very pleased that the upgrade was well worth it.

Thanks for such a wonderful product, Pavel!!

I'll report back in more depth as I get more listening time in and more 'features' enabled; this upgrade entailed a lot of other major changes to the entire system (but not the audio chain downstream of the DAC).

Note: I'm running kind of a 'hybrid' bi-amped stereo/mch system, with the bi-amped stereo mains' crossovers/EQ/Limiters (etc) being implemented downstream of the OktoDAC in a dBX Venu 360 via AES from the OktoDAC, and the surround channels (to be) DSP/EQ'd upstream in JRiver.

Out of interest what version firmware are you running neddy? Mine is running version 1.1.
 

Neddy

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V1.2
 

Feyire

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@Okto Research , has the Stereo version been shipped to Amir? 2nd part of Stereo reveal coming up?
 

DrDardis

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Hey, I have lurked for a bit, but this is post #1. Loving this forum.

I bought this DAC, am waiting on its arrival :). A few questions;

Very recently, Windows included a USB Audio 2.0 driver natively. Does that circumvent the need for ASIO4ALL?
What would be the best way of setting up DIRAC with this DAC? Will it run at system level in windows? or do i have to go the miniDSP route?
 

wineds

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Hey, I have lurked for a bit, but this is post #1. Loving this forum.

I bought this DAC, am waiting on its arrival :). A few questions;

Very recently, Windows included a USB Audio 2.0 driver natively. Does that circumvent the need for ASIO4ALL?
What would be the best way of setting up DIRAC with this DAC? Will it run at system level in windows? or do i have to go the miniDSP route?

The driver question is covered in the manual on the okto website.

https://www.oktoresearch.com/assets/dac8pro/DAC8PRO_owners_manual.pdf
 

DrDardis

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The driver question is covered in the manual on the okto website.

https://www.oktoresearch.com/assets/dac8pro/DAC8PRO_owners_manual.pdf

Ah ok, I misread. I guess that conflicts with the PC-based DIRAC idea then? To run the live processor, it looks like a tool like Equalizer APO is needed, but that has the caveat 'the application must not bypass the system effect infrastructure
(APIs like ASIO or WASAPI exclusive mode can not be used)'. I guess it is a tradeoff sacrificing 'bit perfect'?

Thanks for the advice.
 

wineds

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Ah ok, I misread. I guess that conflicts with the PC-based DIRAC idea then? To run the live processor, it looks like a tool like Equalizer APO is needed, but that has the caveat 'the application must not bypass the system effect infrastructure
(APIs like ASIO or WASAPI exclusive mode can not be used)'. I guess it is a tradeoff sacrificing 'bit perfect'?

Thanks for the advice.

I am not familiar with DIRAC sorry. Hopefully somebody else will chime in.
 

BYRTT

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Ah ok, I misread. I guess that conflicts with the PC-based DIRAC idea then? To run the live processor, it looks like a tool like Equalizer APO is needed, but that has the caveat 'the application must not bypass the system effect infrastructure
(APIs like ASIO or WASAPI exclusive mode can not be used)'. I guess it is a tradeoff sacrificing 'bit perfect'?

Thanks for the advice.

Sorry myself is too lazy read up on that PC-based DIRAC, but will say if its so that it outputs numbers for all the filter setting to set in Equalizer APO, then one can set them filters in Jriver or Foobar configured for ASIO or WASAPI, and if you want whatever Windows sounds routed through that DSP engine then in Jriver one can enable its virtual soundcard input and set that as default for any Windows sounds.
 
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DrDardis

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Sorry myself is too lazy read up on that PC-based DIRAC, but will say if its so that it outputs numbers for all the filter setting to set in Equalizer APO, then one can set them filters in Jriver or Foobar configured for ASIO or WASAPI, and if you want whatever Windows sounds routed through that DSP engine then in Jriver one can enable its virtual soundcard input and set that as default for any Windows sounds.
Ahhh awesome, that's a great tip.
 

Neddy

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Another 'not Dirac' user here, but am using it with JRiver and W10 (fresh install).
I don't recall exactly, but don't think W10 ASIO worked with it 'automatically', so loaded ASIO4ALL (per the manual) and that has worked fine, and does run at the system level in W. (But so far appears to be exclusive.)

My mains/sub xovers & room EQ are downstream of the Okto in a Harman dBX Venu360 (AES inputs), but someday want to try out Dirac for the surround channels, and will use the JR DSP engine/Equalizer APO to implement...so keep us posted on your progress!

One thing I had not anticipated is that the OktoDACs AES (stereo) outputs are at fixed level (0db) and are not muted by the OktoDAC mute function (the remaining channels are). (It's an AES spec thing, I assume.)
Not a huge problem, but means I have to rely on W10/JR's volume control - which I'm not crazy about, esp for 'oops, that got loud' moments.
On the plus side, it makes it really easy to mute the surround channels to compare with Stereo only! :)
Welcome to the OktoDAC club - enjoy!
 

g29

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...
Not a huge problem, but means I have to rely on W10/JR's volume control - which I'm not crazy about, esp for 'oops, that got loud' moments.
On the plus side, it makes it really easy to mute the surround channels to compare with Stereo only! :)
Welcome to the OktoDAC club - enjoy!

FWIW, JRMC has WMD, Loudness, Internal Volume and Volume Protection functions.

- WMD funnels other program's sound through JRMC's volume controls and DSP.
- Loudness feature implements "equal loudness curves" at varying SPL levels (optional)
- Volume Protection implements startup volume and MAX volume levels
- Internal Volume is implemented in 64-bit and is separate from Windoze's System Volume
 

g29

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Hey, I have lurked for a bit, but this is post #1. Loving this forum.

I bought this DAC, am waiting on its arrival :). A few questions;

Very recently, Windows included a USB Audio 2.0 driver natively. Does that circumvent the need for ASIO4ALL?
What would be the best way of setting up DIRAC with this DAC? Will it run at system level in windows? or do i have to go the miniDSP route?

I you haven't bought DIRAC already, please note there are other options out there (REW/RePhase, Audiolense, Acourate) that maybe more versatile/feature rich depending on your application.

Are you planning on doing multi-channel audio or multi-amping 2-channel ???
 

Neddy

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FWIW, JRMC has WMD, Loudness, Internal Volume and Volume Protection functions.

- WMD funnels other program's sound through JRMC's volume controls and DSP.
- Loudness feature implements "equal loudness curves" at varying SPL levels (optional)
- Volume Protection implements startup volume and MAX volume levels
- Internal Volume is implemented in 64-bit and is separate from Windoze's System Volume

Yes, and OktoDAC has max volume settings as well - but I prefer to rely on the Venu's peak limiters, which are highly adjustable:
1580583140465.png
 

DrDardis

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Are you planning on doing multi-channel audio or multi-amping 2-channel ???

Multichannel for plex, netflix etc and stereo for roon, spotify etc.

I currently have;
5.1 = Shield -> Denon (also powering non-stereo speakers) -> Musical Fidelity M3i HT bypass for L/R (all using Denons pretty average audessy)
2.0 = Allo DigiOne and linear PSU -> Topping DX7s Dac -> Musical Fidelity M3i
2 x SVS sealed subs are corrected with a DSPeaker Dualcore I picked up on the cheap.

...very convoluted. Sounds ok for stereo, but average for 5.1.

My plans are;
Nice silent pc build (DSP on the pc for room correction) -> OktoDAC -> nCore amps and the subs.

...simple, and handles everything. It should sound great. Minimum boxes too.

Not wedded to Dirac, but do prefer it over REW for the time-domain aspect. Audiolense looks interesting too. Dirac seems the most user-friendly, that's all. Luckily I have not purchased anything yet besides the OktoDAC. Feedback/suggestions welcome :).
 
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