Okto 8 Owner’s Thread

[mdsimon2]

miniDSP nanoDIGI or DDRC-88D are good options but do not have multiple inputs.

If you are DIY inclined you can build an all digital DSP based on a miniSHARC + DIGI-FP + clock buffer + 4X WM8805 I2S to AES boards for ~$900. This will give you three inputs (AES, SPDIF, TOSLINK). I have done this myself but am still waiting on my DAC8 Pro (order 208) to arrive to put it in to action.

Michael

 

[dualazmak]

Is there a practical device that you can use with the DAC 8 pro for active crossover or DSP?

I would be happy if my mutlichannel multi-amplfier project cound be a reference for you...

 

[Maltman]

miniDSP nanoDIGI or DDRC-88D are good options but do not have multiple inputs.

If you are DIY inclined you can build an all digital DSP based on a miniSHARC + DIGI-FP + clock buffer + 4X WM8805 I2S to AES boards for ~$900. This will give you three inputs (AES, SPDIF, TOSLINK). I have done this myself but am still waiting on my DAC8 Pro (order 208) to arrive to put it in to action.

Michael

where can I find more information about your built?

 

[Maltman]

I would be happy if my mutlichannel multi-amplfier project cound be a reference for you...

Of course I read your project thread, but it’s a 2.2 setup Right? Also you’re still using an AVR?

 

[abdo123]

I would be happy if my mutlichannel multi-amplfier project cound be a reference for you...

Your project makes sense to people who only listen to digital files on their PCs.

But i also listen to LPs and connect my speakers to my TV. It could be done but it wouldn’t be practical anymore.

 

[mdsimon2]

where can I find more information about your built?

I have a more detailed write up coming as I want to make sure that everything works as it should with the Okto. I do not currently have a DAC that will take all 8 channels of AES output but I have tested each output individually and done some basic frequency response / distortion testing. Brief summary of the build and some pictures are attached. Definitely not the prettiest but it will be hidden away in a cabinet.

OpenDRC-DI (miniSHARC DSP + DIGI-FP I/O board)
Ian Canada McFIFO/McDualXO (clock buffer / FIFO)
Conwin 24.576 MHz Oscillator (need a 24.576 MHz clock if the miniSHARC is running at 48 kHz, can use other options like Crystek 957 but this is plug and play)
WMM8805 I2S to AES Board (x4)

Michael

 

[mdsimon2]

I should also note that my primary motivation is stereo active speakers (4 way) including FIR correction. Therefore I do not mind that this only has stereo inputs. If you do not need FIR and need 8 channels of input the DDRC-88D will work better for you at a similar cost.

Michael

 

[abdo123]

I have a more detailed write up coming as I want to make sure that everything works as it should with the Okto. I do not currently have a DAC that will take all 8 channels of AES output but I have tested each output individually and done some basic frequency response / distortion testing. Brief summary of the build and some pictures are attached. Definitely not the prettiest but it will be hidden away in a cabinet.

OpenDRC-DI (miniSHARC DSP + DIGI-FP I/O board)
Ian Canada McFIFO/McDualXO (clock buffer / FIFO)
Conwin 24.576 MHz Oscillator (need a 24.576 MHz clock if the miniSHARC is running at 48 kHz, can use other options like Crystek 957 but this is plug and play)
WMM8805 I2S to AES Board (x4)

Michael

Does it have an ADC or is it my eyes tricking me?

 

[mdsimon2]

Does it have an ADC or is it my eyes tricking me?

No ADC but I use a Raspberry Pi 3B+ with a Hifiberry DAC+ ADC Pro for my turntable and stream this losslessly to another Raspberry Pi 3B+ with an Allo DigiOne connected to the DSP using LMS and the Wave Input plugin.

Michael

 

[Maltman]

I have a more detailed write up coming as I want to make sure that everything works as it should with the Okto. I do not currently have a DAC that will take all 8 channels of AES output but I have tested each output individually and done some basic frequency response / distortion testing. Brief summary of the build and some pictures are attached. Definitely not the prettiest but it will be hidden away in a cabinet.

OpenDRC-DI (miniSHARC DSP + DIGI-FP I/O board)
Ian Canada McFIFO/McDualXO (clock buffer / FIFO)
Conwin 24.576 MHz Oscillator (need a 24.576 MHz clock if the miniSHARC is running at 48 kHz, can use other options like Crystek 957 but this is plug and play)
WMM8805 I2S to AES Board (x4)

Michael

Looks great, but i dont need a ADC. Im just looking for more digital inputs for the Okto. Lets say: PC > USB > Okto, thats the main channel. Now i can add SPDIF RCA (7.1 Signal) to one of the 4 AES inputs on the Okto right? For HDMI i have to split A/V to SPDIF. Is there a DIY solution for HDMI A/V split like HDMI A/V in, HDMI V out + SPDIF out?

 

[abdo123]

No ADC but I use a Raspberry Pi 3B+ with a Hifiberry DAC+ ADC Pro for my turntable and stream this losslessly to another Raspberry Pi 3B+ with an Allo DigiOne connected to the DSP using LMS and the Wave Input plugin.

Michael

How long did it take for you to learn how to do all of this? Sir this is impressive !

Do you use a phono stage or you do RIAA equalization digitally?

 

[mdsimon2]

How long did it take for you to learn how to do all of this? Sir / Madame this is imprrssive!

Do you use a phono stage or you do RIAA equalization digitally?

I bought the OpenDRC-DI in August and it has been a slowly moving project since then. Definitely quite a bit of learning along the way. At first I tried to get away with not using a clock buffer and just routing the miniSHARC directly to the WM8805 boards but that was unreliable. Once I got the McFIFO / McDualXO everything started to come together very nicely.

Like I said I plan on a much longer write up to help others do something similar once I know 100% that it works well with the Okto.

I use a phono stage prior to the ADC.

Michael

 

[mdsimon2]

Looks great, but i dont need a ADC. Im just looking for more digital inputs for the Okto. Lets say: PC > USB > Okto, thats the main channel. Now i can add SPDIF RCA (7.1 Signal) to one of the 4 AES inputs on the Okto right? For HDMI i have to split A/V to SPDIF. Is there a DIY solution for HDMI A/V split like HDMI A/V in, HDMI V out + SPDIF out?

I am not very familiar with multichannel setups but I know that you will not be able to route a 7.1 signal to a single AES input as the AES inputs are stereo.

Michael

 

[Neddy]

An HDMI to (4)AES converter would make a nice HT solution, but are effectively unobtainium.
So, for HT I'm running a good USB ADC off an Oppo analog outputs for that (also, via a switch, Phono pre-amp outputs).
Regarding the DSP question, I'm using the Okto CH1&2 AES outputs, to a Venu360 for bi-amping, REQ, crossovers, etc, also with the CH4 sub output mixed in for sub xovers.
Okto is an excellent swiss army audio 'knife'.

 

[mdsimon2]

An HDMI to (4)AES converter would make a nice HT solution, but are effectively unobtainium.
So, for HT I'm running a good USB ADC off an Oppo analog outputs for that (also, via a switch, Phono pre-amp outputs).
Regarding the DSP question, I'm using the Okto CH1&2 AES outputs, to a Venu360 for bi-amping, REQ, crossovers, etc, also with the CH4 sub output mixed in for sub xovers.
Okto is an excellent swiss army audio 'knife'.

So you have another ADC/DAC downstream of the Okto? In that case what is the point of the Okto? Why not just got straight in to the Venu360?

Michael

 

[Neddy]

No, it's a USB ADC only (Motu 8Pre), upstream of the PC & Okto, so all audio inputs go through JRiver. (And I'm using a Roko on the Oppo HDMI input to add streaming to that solution.)
The Venu is only for main speaker bi-amping/crossovers, DSP, etc. Using AES bypasses the Venu's ADC.

 

[dualazmak]

Your project makes sense to people who only listen to digital files on their PCs.

But i also listen to LPs and connect my speakers to my TV. It could be done but it wouldn’t be practical anymore.

OK, understood... I have already digitized all of my about 500 LPs in 192 kHz AIFF format using Audacity while still keeping Denon DP-57L player for possible further LP into AIFF conversion. I seldom listen TV with my multichannel audio system...

 

[phoenixdogfan]

Just put in an order for a Dac 8 Pro. I ordered it with a custom output voltage. I ordered outputs 1-6 to be set for 12 volts RMS. I thought I read somewhere that they could be set to a maximum of 17v RMS. I have a Purifi Eval 1 and use Dirac Live Studio 3 on my PC. My thought is that I could use Ekio as a basis or a very high quality 5.1 surround, and use the remaining two channels of dac to drive my THX 789. Anyone know anything about the custom output voltage? Whether it can be set higher than 12 v and if that would in any way compromise performance or reliability? And what's the wait time on order fulfillment?

 

[mdsimon2]

Just put in an order for a Dac 8 Pro. I ordered it with a custom output voltage. I ordered outputs 1-6 to be set for 12 volts RMS. I thought I read somewhere that they could be set to a maximum of 17v RMS. I have a Purifi Eval 1 and use Dirac Live Studio 3 on my PC. My thought is that I could use Ekio as a basis or a very high quality 5.1 surround, and use the remaining two channels of dac to drive my THX 789. Anyone know anything about the custom output voltage? Whether it can be set higher than 12 v and if that would in any way compromise performance or reliability? And what's the wait time on order fulfillment?

Do not know anything about custom voltage other than the website saying you can get custom voltages from 1V to 12V.

Not sure why you would want an output voltage above 12V as I imagine all that would do is force you to lower the volume (and reduce SINAD as a result). I am not super familiar with Purifi but I assume your plan is to bypass the pre-gain so you only have a gain of 13 dB in the amp? Seems to me like 12V would be plenty in this case as you would still be able to drive the amplifier to full power. That being said not sure how often you change gear but having a 12V output voltage is excessive for most typical power amplifiers with 25-30 dB voltage gain.

In terms of fulfillment time I ordered a DAC8 Pro in the beginning of September and have not received it (~18 weeks to date). I am told it should be completed soon.

Michael

 

[phoenixdogfan]

Do not know anything about custom voltage other than the website saying you can get custom voltages from 1V to 12V.

Not sure why you would want an output voltage above 12V as I imagine all that would do is force you to lower the volume (and reduce SINAD as a result). I am not super familiar with Purifi but I assume your plan is to bypass the pre-gain so you only have a gain of 13 dB in the amp? Seems to me like 12V would be plenty in this case as you would still be able to drive the amplifier to full power. That being said not sure how often you change gear but having a 12V output voltage is excessive for most typical power amplifiers with 25-30 dB voltage gain.

In terms of fulfillment time I ordered a DAC8 Pro in the beginning of September and have not received it (~18 weeks to date). I am told it should be completed soon.

Michael

Yikes! 18 weeks, yikes! Almost as bad as the A16 Realiser.