Okto Research dac8 PRO D/A processor

For multichannel music fans, there is a fork in the road. You can take the well-traveled route based on readily available AVRs and preamp-processors intended for home theater. Or you can take the purist's route and face the challenge of finding a suitable and affordable multichannel DAC. Now that the $299, PCM-only miniDSP U-DAC8 has been withdrawn from the market, the least expensive multichannel DAC is the Merging Anubis at around $2000. That entry fee is a significant barrier for many.

For a couple of years, I have been following Prague-based Okto Research. At first, Pavel Krasensky, the founder and hardware developer, offered audio design ideas and DIY modules that I found tantalizing. For example, there was a dandy-looking ESS 9038Pro Sabre–based output module and some appealing power supply modules—but to use those, the buyer had to manage inputs and integration on their own.

He followed this with a few assembled prototypes with limited availability. Then, finally, last year, he released the dac8 PRO.

Because Okto had many followers, he was able to start promoting and beta-testing the dac8 PRO via a "tour." The device was dispatched to an interested party for evaluation, then passed on, ad seriatim. The dac8 PRO got great feedback, which led to more exposure. He began to take orders.

Delivery times are still long. Most of us who are interested have been waiting for our turn. My turn finally arrived.

What it is
The dac8 PRO is an 8-channel D/A processor with USB input and output, 8 channels of AES/EBU input, and 8 channels of balanced (XLR) analog output as well as a headphone output (THD+N specified as –113dB THD+N @ 100mW into 32 ohms) and a stereo AES/EBU output. (It outputs digital data corresponding to the first two channels.) The specifications indicate THD+N of –119dB and a 125dB dynamic range (20Hz–20kHz).

There's a choice of seven PCM reconstruction filters. Its nifty front-panel volume control and display obviates the need for a preamp in a dedicated system, works with the Apple remote, and is based on the ESS Sabre DAC. Output level can be customized for optimal system-matching. All for €989 (equivalent to $1169 as of early September 2020), plus shipping (footnote 1).

How it sounds
I found the dac8 PRO to be a great-sounding DAC with many potentially useful features, such as the ability to synchronize with other dac8s for 16 or more channels. It has native MacOS and Linux compatibility, which is why I needed it for the Pink Faun review elsewhere in this issue (footnote 2). A generic ASIO driver allows it to work well in Windows world. I've used it with Roon, JRiver Media Center, Qobuz, and system-default output. It handles PCM up to 32/192 and DSD up to DSD128.

For now, all sales, support, and service is provided by Okto in Prague, so it does not pass Stereophile's traditional rules for a feature review (footnote 3). But I was so impressed that I caucused for reconsideration. Subsequently, Editor-in-Chief Jim Austin approved this brief report and John Atkinson agreed to put it on his test bench. JA1's results will appear along with his forthcoming review of the recently released Okto dac8 Stereo.

To misquote Magritte, "This is not a review!" I bought it, though, and I'm glad I did!

Footnote 1: For more details, see here.

Footnote 2: See the Pink Faun review for details of the system used to audition the dac8 PRO.—Editor

Footnote 3: That rule exists to ensure that owners receive respectable product support. Currently, the dac8 PRO must be returned to the Czech Republic for service, at the owner's expense, and we don't know how long it takes. But, considering the scarcity of multichannel DACs and the apparent high quality and good value offered by the dac8 PRO—and considering that there's a 30-day at-home evaluation period (although if you decide not to keep it, it has to be shipped back to Prague, again at the auditioner's expense). I decided to give it some Stereophile love.—Editor

tonykaz's picture

Thank you for helping to educate me. Immediately I searched for useful definition for "ad seriatim". hmm Dam, it seems legal but useful for describing the endless stream of Audio Gear making their way thru my curious ownership.

and Magritte, who I presume is the surrealistic painter.

Cheap, cheap, cheap!!!

Isn't this piece of gear a 'give-away' considering today's state of affairs in High-End? Perhaps this quoted price is about as logical as a Magritte piece of art. hmm.

Thank you for including us in your fascinating journey into the world immersive sound. We have an IMAX theatre nearby, I wonder what gear they use.

Someone referred to you as Dr.Kal, are you a medical man?

Tony in Venice

JRT's picture

I have been looking forward to Kal's review (report?) of the Okto Research dac8 PRO multichannel D/A processor since it was briefly discussed here many months ago.

Also happy to see Jim Austin relaxing rules in this case that would have otherwise barred such review (report?).

I am a subscriber, and will look forward to John's measurements.

Stay well.

JRT's picture

I did not see any mention of that on the product webpage at Okto's website, or in the manual downloaded from the link provided there.

Could you please explain a litle about how a second unit would be slaved to the first, the interconnection, etc.?

Kal Rubinson's picture

Sure. Feed the AES/EBU output of the first DAC (in pure USB mode) to the AES/EBU Input 1 (Channels 1-2) of the second DAC and put the second DAC into "USB/AES" mode. You can daisy-chain additional DAC8s from the second one, if needed. In this arrangement, the link conveys the synch but you may have to sacrifice on pair of channels on each of the DAC8s except for the first one. That means the following DAC8s are, effectively, DAC6s.

The remaining job is to have your source component recognize the individual DAC8s and send the proper signals to each. You are most likely to achieve this with a Mac and JRiver since MacOS allows you to aggregate multiple USB devices into a single "virtual" multichannel device which JRiver recognizes as such.

There is a thread about this on ASR and I will append a link to it when I can. It is not simple "plug-and-play."

JRT's picture


dualazmak's picture

Kal, very happy to find your nice introduction of DAC8PRO here in Stereophile after you helped me a lot on DAC8PRO at the ASR thread!

Just for Stereophile audio enthu friends' reference, I am intensively building my multichannel multi-amplifier audio system using DAC8PRO and software crossover EKIO on Windows 10 PC.


If this kind of citation would not be suitable/feasible here, please delete the above link without hesitation.

MhtLion's picture

I believe this processor can be used as 2 channel only DAC, right?