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Okto Research modules

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Thank you for your reply.

The UDIO-8 is just an USBstreamer with an additional I/O card that turn I2S into AES in/outs. I as thinking about directing the I2S outputs from the USBstreamer to the DAC8, but keep the inputs cooonected to the AES card.
At this point it might be simpler to install the I2S firmware in the USBstreamer and just use the toslink as input. I need to read the USBstreamer manual it seems :D

Regarding pop noises, I made a typo: my question should read "Is your DAC completely pop-free on turnon/turnoff or sampling freq change?". So just to be sure, completely pop/click/noise free in any even, even in case of brutal power outage?
 
Hello everyone,

we decided to react to demand for a stereo version of DAC8 with a simple, yet unique stereo mode that turns 8 high-performance channels of DAC8 into 2 ultra-performance channels.

With our implementation of stereo mode, 4+4 I/V stages work in parallel, which is effectively 4x averaging. Dynamic range gets increased (and RMS noise decreased) by a factor of sqrt(N) for N-times averaging, which means a factor of 2 in our case. This pushes the dynamic range of DAC8 to around 132dB and THD+N to around 0.0001% (-120dB). Notice that these are real-world measured values, not just a datasheet-based assumption.

Switching between stereo and 8-channel mode consists of placing a small connector board across output pin headers and placing a jumper to a GPIO pin. These items will be included with all new orders. More information can be found in the DAC8 manual.

Also, our e-shop now supports card payments!

Thank you for your support,

Pavel Krasensky, DAC8 designer

info@oktoresearch.com
Okto Research
 
Nice!
Would you consider sending a test unit (DAC8+PSU+USBstreamer in a case) to Amir at audiosciencereview for an independent measurement of both the stereo and 8 channels modes?
If he also measures the same performance that would put your DAC ahead of anything he has measured so far, and it would gain popularity.
 
I think that UDIO-8 is working on I2S and it should be easy to use your old inputs and OKTO DAC8 outputs together.

DAC8 is completely pop/click/noise free.

Enticing but the USBStreamer and the U-DIO8 are limited to 24/192PCM, nothing more in PCM and no DSD. Is there any similar device that will take advantage of the higher resolution capabilities of the DAC8?
 
Nice!
Would you consider sending a test unit (DAC8+PSU+USBstreamer in a case) to Amir at audiosciencereview for an independent measurement of both the stereo and 8 channels modes?
If he also measures the same performance that would put your DAC ahead of anything he has measured so far, and it would gain popularity.
Definitely, that's a great idea. I love the title and description of their vendor's forum, we need to start a thread there too...

Enticing but the USBStreamer and the U-DIO8 are limited to 24/192PCM, nothing more in PCM and no DSD. Is there any similar device that will take advantage of the higher resolution capabilities of the DAC8?
Contrary to what marketing people say, playback at higher sample rates does not bring "higher resolution capabilities". In fact, exactly the opposite. Sabre DACs (and I'm pretty sure other DAC chips too) have worse linearity and produce more pronounced high-order harmonics when operated at high sample rates. I would just say it's best to avoid 384kHz or even 768kHz operation if striving for most pristine analog output. I had a quick look in a datasheet of a flagship AKM part and it looks like they have even bigger problem with that.
https://www.akm.com/akm/en/file/datasheet/AK4497EQ.pdf (page 11)

Funny thing is that all these chinese DAC modules on Ebay try to catch buyer's eye on highest sample rate capability, trying to persuade them that sample rate equals resolution.

Having said that, I do not question the use of high sample rates in general, it makes sense in recording and post-processing. There is just no point in trading performance in audible range for wider inaudible range.

Speaking of DSD, Sabre does internally convert all the incoming data to a proprietary DSD-like bitstream.
 
Contrary to what marketing people say, playback at higher sample rates does not bring "higher resolution capabilities". In fact, exactly the opposite. Sabre DACs (and I'm pretty sure other DAC chips too) have worse linearity and produce more pronounced high-order harmonics when operated at high sample rates. I would just say it's best to avoid 384kHz or even 768kHz operation if striving for most pristine analog output. I had a quick look in a datasheet of a flagship AKM part and it looks like they have even bigger problem with that.
https://www.akm.com/akm/en/file/datasheet/AK4497EQ.pdf (page 11)
I appreciate that and, although I can play at higher rates, I usually downsample on-the-fly in order to use DSP tools. However, I need to have the ability to play at 352.8/384kHz anyway for test and evaluation purposes.

Speaking of DSD, Sabre does internally convert all the incoming data to a proprietary DSD-like bitstream.
As above, playback of DSD is essential.

So, this was not targetted at the DAC8 but at how I might be able to use the DAC8 if the obvious interfacing devices (USBStreamer and U-DIO8) are not sufficient.
 
For stereo DSD playback over USB, there certainly are options out there - Amanero Combo384, I2SoverUSB by JLSounds and DIYINHK Xmos module to mention three.

I don't know about any multichannel one however. Question is how many people need 8-channel DSD playback given the fact that to this point majority of our customers bought DAC8 to use it with some sort of DSP which generally do not support DSD at all.
 
Nice!
Would you consider sending a test unit (DAC8+PSU+USBstreamer in a case) to Amir at audiosciencereview for an independent measurement of both the stereo and 8 channels modes?
If he also measures the same performance that would put your DAC ahead of anything he has measured so far, and it would gain popularity.

That would be a very interesting comparison since they just reviewed MiniDSP SHD.
 
We now also offer custom builds of DAC8 in enclosures together with third-party products like those from MiniDSP.

Here are photos of one we did recently for a customer who owns an Oppo UDP-203 player with Vanity 203HD module, input is galvanically isolated I2S.

Contact us on info@oktoresearch.com if you are interested.

Very sexy, will be saving and placing an order soon!
 
Hi
I m considering this solution together with a NanoSharc to do almost same s Minidsp SHD.
What about jitter performance of the whole solution using the default ESS jitter eliminator in slave mode ?
a test to audio science would provide a way to compare with the latest minidsp shd, as it shows relatively bad figures for this

thx!
 
Hi guys,

Nice product, congratulations!
Actually I'm looking for an alternative USB driven device controlled with a PC using "Acourate Convolver" as an active crossover (6ch or 8ch). No idea, if you know that Software, but I'd like to avoid problems regarding drivers, incompatibilities etc. Do you have any experience with that?
It would be a pleasure to test your DAC8 and finally replace my setup.

Best regards

Stammheim
 
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Hello everyone,

sorry for the delayed answer. We are working hard on our upcoming product - a DAC8 as a complete unit with 8-channel USB input, OLED front panel and remote control, which we would like to unveil in less than a month. We got a lot of e-mails lately showing support and interest, so thanks for that.

pos: Having our DAC reviewed by Audiosciencereview is a great opportunity to show not only measured performance, but also design (which we have put a lot of effort into) of our new unit to a wider audience. We don't want to miss that opportunity, so we're going to wait with that until we have it done.

maxidcx: If I remember correctly, according to measurements done by ESS (and published as a PDF few years ago), Sabre's jitter eliminator is able to reject up to 1ns of jitter without performance degradation. Our own tests have confirmed that it indeed seems to be jitter-agnostic, so I wouldn't worry about that very much.

Stammheim: Thanks. We haven't tested Acourate specifically, but we do have positive experience with PC-based crossover using JRiver's DSP engine, which does include convolver too. We got your e-mail and we're going to reply soon.

Kind regards,

Pavel
 
pos: Having our DAC reviewed by Audiosciencereview is a great opportunity to show not only measured performance, but also design (which we have put a lot of effort into) of our new unit to a wider audience. We don't want to miss that opportunity, so we're going to wait with that until we have it done.
Please contact me when ready. I usually have more time to test things later in the year anyway.

Best of luck in getting the unit into manufacturing.

Amir
Audio Science Review
 
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