Review and Measurements of Okto DAC8 8Ch DAC & Amp

[Dave H]

Ive just noticed Okto web page has now been updated, manual now available. https://www.oktoresearch.com/dac8pro.htm#!

 

[g29]

Ive just noticed Okto web page has now been updated, manual now available. https://www.oktoresearch.com/dac8pro.htm#!

Thanks. The documentation is vague on Windows 7 and WASAPI exclusive support.

"... On Mac OS and Linux, no driver is needed thanks to the USB Audio Class 2.0 standard used by the unit, and the DAC8 PRO will be recognized as an 8-channel playback device and an 8-channel recording device. The only action required by the user is to select the DAC8 PRO in your operating system’s audio control panel.

This also applies to Windows 10 and newer, however, it is strongly recommended to use ASIO to bypass the Windows sound mixer and allow for an exclusive access to the device and a bit-perfect data transport. Please contact us if you are interested in using the DAC8 PRO with older Windows operating systems ..."

 

[LuckyLuke575]

Ive just noticed Okto web page has now been updated, manual now available. https://www.oktoresearch.com/dac8pro.htm#!

This DAC looks boss; almost too high spec to be in a home environment, it looks more like something you'd find in a production studio. Is it a 'prosumer' device? Also no RCA??? So I guess its balanced or bust, which is a pity because it really limits the options. I'd much rather just have a Topping D50s.

 

[g29]

... Also no RCA??? So I guess its balanced or bust, which is a pity because it really limits the options. ....

Search this thread for the RCA/unbalanced discusions and design decisions not to use it. It has been covered a few times before.

 

[HammerSandwich]

Thanks. The documentation is vague on Windows 7 and WASAPI exclusive support.

Win7 has 3 more months of updates. Time for people to plan to switch to 10 or Linux.

"... On Mac OS and Linux, no driver is needed thanks to the USB Audio Class 2.0 standard used by the unit, and the DAC8 PRO will be recognized as an 8-channel playback device and an 8-channel recording device.

Wait, what? It can push the AES/EBU inputs to a Linux PC via USB, then also provide Okto-class outputs??!!? Suddenly, I'm not missing the MiniDSP option.

 

[bigjacko]

Have seen some posts talking about xlr to rca on this thread, I want to know how much degrade to the sound if use the pin 3 floating way? Are the degrade all from without common mode rejection or from new distortion induced in circuit? A lot of people already said if no ground loop etc, single ended is good enough. Also will the stereo one have whole different circuit to 8 channel one if their performance are not the same? Or they are the same but only two channel makes the circuit layout better, so higher performance?

 

[wineds]

Have seen some posts talking about xlr to rca on this thread, I want to know how much degrade to the sound if use the pin 3 floating way? Are the degrade all from without common mode rejection or from new distortion induced in circuit? A lot of people already said if no ground loop etc, single ended is good enough. Also will the stereo one have whole different circuit to 8 channel one if their performance are not the same? Or they are the same but only two channel makes the circuit layout better, so higher performance?

Maybe the headphone output could be used as a single ended output?

 

[g29]

Win7 has 3 more months of updates. Time for people to plan to switch to 10 or Linux.....

FWIW, Win 98 is still alive and well in many installations. Win7 will live at least as long. Win10 updates have been killing the KTBD and probably other audio devices, not so with Win7.

... Also will the stereo one have whole different circuit to 8 channel one if their performance are not the same? Or they are the same but only two channel makes the circuit layout better, so higher performance?

The STEREO is paralleling 4 channels into 1 for lower SINAD and more dynamic range (6dB). Check out the noise and dynamic range specs between the PRO and STEREO units posted on their website. The STEREO version also has a Raspberry PI, more inputs, fewer outputs, so internals will be different.

 

[bigjacko]

Maybe the headphone output could be used as a single ended output?

I thought that headphone output cannot be used as amp input because of impedance not suitable. But I have seen some people saying they want to use E1DA 9038 hook to an amp. Not sure about how that would work, guess there is a way that we can bypass some impedance issue.

 

[wineds]

I thought that headphone output cannot be used as amp input because of impedance not suitable. But I have seen some people saying they want to use E1DA 9038 hook to an amp. Not sure about how that would work, guess there is a way that we can bypass some impedance issue.

Manual shows it is very low impedance out (output impedance <100 mOhm) so this ought not be an issue. But of course ground loops still could be an issue.

 

[SpyB]

Anyone wanting to purchase the Okto DAC and requiring XLR to RCA,
Try This
https://www.neutrik.com/en/product/na2f-d0b-tx

 

[Okto Research]

Win7 has 3 more months of updates. Time for people to plan to switch to 10 or Linux.

Wait, what? It can push the AES/EBU inputs to a Linux PC via USB, then also provide Okto-class outputs??!!? Suddenly, I'm not missing the MiniDSP option.

Yep, real-time filtering on a host computer is one of the intended use cases.

Have seen some posts talking about xlr to rca on this thread, I want to know how much degrade to the sound if use the pin 3 floating way? Are the degrade all from without common mode rejection or from new distortion induced in circuit? A lot of people already said if no ground loop etc, single ended is good enough. Also will the stereo one have whole different circuit to 8 channel one if their performance are not the same? Or they are the same but only two channel makes the circuit layout better, so higher performance?

No, single ended connections are not enough for quality audio. Omitting RCAs is our little contribution in pushing the industry in the right direction. Also, we don't need to worry about "I get hum when my Okto Research device is connected to an XYZ amplifier" type of support.

I tried to cover the topic (and possible ways to interface to equipment with single-ended inputs only) here:
https://www.audiosciencereview.com/...kto-dac8-8ch-dac-amp.7064/page-28#post-207485

And this is probably the best reading on the subject, delightfully written and spot on:
https://www.hypex.nl/img/upload/doc/an_wp/WP_The_G_word.pdf

Cheers,
Pavel

 

[Olivier]

Hi all,

Okto Research recommends using Roon (or equiv.) + nuc with the Okto Dac 8 pro in active filtering systems. However how can we easily manage the acoustic correction of the room via this system? I now use the Dirac Live software included in the miniDSP Studio SHD and the quality of room correction with this device is very high. Is there a way to include Dirac Live in Roon or in any equivalent software?

Best, Olivier.

 

[tensor9]

@Okto Research
Can you tell us how the DAC8 Stereo handles volume control?

 

[Okto Research]

@Okto Research
Can you tell us how the DAC8 Stereo handles volume control?

32-bit digital volume inside the Sabre DAC chip.

 

[tensor9]

32-bit digital volume inside the Sabre DAC chip.

That’s too bad, I was looking for some degree of analog attenuation.

 

[Okto Research]

That’s too bad, I was looking for some degree of analog attenuation.

The analog volume does make sense when the dynamic range of the device is not high enough to make noise inaudible at 100% volume (0dB attenuation). The noise gets attenuated together with the audio signal.

With digital volume, only the audio signal is affected and the noise level is fixed. If it is low enough to begin with, then there is no reason not to go this was since it is fluent, click-free (both in terms of processed signal and possible relays involved) and has 100% channel-to-channel matching.

 

[Bliman]

The analog volume does make sense when the dynamic range of the device is not high enough to make noise inaudible at 100% volume (0dB attenuation). The noise gets attenuated together with the audio signal.

With digital volume, only the audio signal is affected and the noise level is fixed. If it is low enough to begin with, then there is no reason not to go this was since it is fluent, click-free (both in terms of processed signal and possible relays involved) and has 100% channel-to-channel matching.

Would you give up a heads up here if you send the Stereo Dac for review? And do you have an idea already when it would happen?

 

[tensor9]

The analog volume does make sense when the dynamic range of the device is not high enough to make noise inaudible at 100% volume (0dB attenuation). The noise gets attenuated together with the audio signal.

With digital volume, only the audio signal is affected and the noise level is fixed. If it is low enough to begin with, then there is no reason not to go this was since it is fluent, click-free (both in terms of processed signal and possible relays involved) and has 100% channel-to-channel matching.

Yeah, but I just hate losing the dynamic range when there are solutions that can completely avoid it. I know it's won't necessarily be audible, but stil...

 

[Okto Research]

Yeah, but I just hate losing the dynamic range when there are solutions that can completely avoid it. I know it's won't necessarily be audible, but stil...

Well, the same happens with an analog volume (or attenuator). The tyranny of reality makes us unable to enjoy the full dynamic range of our hi-fi equipment at low volume simply by the existence of a non-zero sound pressure level in our listening rooms. There is around 20-30dB SPL in a very quiet one.

Also, with very few exceptions (like the Benchmark AHB2), the noise of the amplifier will be higher than the one of the DAC8 Stereo multiplied by the voltage gain of the amplifier. So the analog attenuator in DAC doesn't really make sense. An ideal way of implementing the analog volume would be by varying voltage gain of an amplifier, but that is very difficult to do since audio amplifiers like to work in a narrow range of voltage gain.

Would you give up a heads up here if you send the Stereo Dac for review? And do you have an idea already when it would happen?

I cannot confirm whether we will give a heads up or make it a surprise. The DAC8 Stereo hasn't been sent for a review yet.

Cheers,
Pavel