Review and Measurements of Okto DAC8 8Ch DAC & Amp

[jan.didden]

Just ordered my OKTO DAC 8 Pro. In perusing the user guide, there appears to be a menu item where you can input a number between -99 and +99 as 'correction' to the DAC to cancel or minimize H2 and H3 (2 inputs). From the text I assume this is done by feeding a clean signal and looking at the output (analog?) until H2 and H3 are minimum.
Has anyone here tried that function, and what were the findings?

Jan

 

[JP]

Interesting. Too bad I’ll likely not see new features like that for the DAC 8 DSP.

 

[Iceee]

Hi, I would connect Okto dac 8 pro (8ch) to multiple Arendal 1723 2s subs and to power amp (for dirac live bass control) :
https://apollonaudio.com/product/hypex-ncx500-ncorex-st-stereo-amplifier/

Apollon has Gain (dB): 12,8/20,5/27,5/29. What is optimal gain from that 4 options, or do you recommend custom voltage upgrade and what number in volts should I order for best results with Apollon amp from above?

Arendal 1723 2s sub has switchable input voltage 1V, 2V, 4V & 8V so I assume Okto dac used as preamp should have the same voltage from that 4 options from Arendal. ASR did review for dac 8 pro and it was measured 3.3v ouput

 

[juliangst]

Hi, I would connect Okto dac 8 pro (8ch) to multiple Arendal 1723 2s subs and to power amp (for dirac live bass control) :
https://apollonaudio.com/product/hypex-ncx500-ncorex-st-stereo-amplifier/

Apollon has Gain (dB): 12,8/20,5/27,5/29. What is optimal gain from that 4 options, or do you recommend custom voltage upgrade and what number in volts should I order for best results with Apollon amp from above?

Arendal 1723 2s sub has switchable input voltage 1V, 2V, 4V & 8V so I assume Okto dac used as preamp should have the same voltage from that 4 options from Arendal. ASR did review for dac 8 pro and it was measured 3.3v ouput

I think the Okto allows you to adjust the level for each channel independently and the master volume will respect those changes.
You could go for the highest voltage Oktodac option and lower the gain if required.
But even the standard voltage should work fine if you select a higher gain (lower input voltage) on your amp and subs.

 

[Iceee]

I spoke directly to Okto and Apollon, if someone needs this useful info:

ideal gain on Apolon Ncx500 for all Okto dacs is 20.5db (4Vrms), cause Both Okto dac stereo & pro (8ch) put out 4.2V. So you use all the power from amp at 20.5db gain setting . Pavel from Okto also mentioned that only test unit dac (8ch) was 3.3v, that is no longer the case.

 

[nagster]

Just ordered my OKTO DAC 8 Pro. In perusing the user guide, there appears to be a menu item where you can input a number between -99 and +99 as 'correction' to the DAC to cancel or minimize H2 and H3 (2 inputs). From the text I assume this is done by feeding a clean signal and looking at the output (analog?) until H2 and H3 are minimum.
Has anyone here tried that function, and what were the findings?

Jan

I noticed your post yesterday. It may have already arrived, but I'll post anyway. I don't have a PRO, so I measured it in Stereo.

 

[wav3form]

This might be a silly question but can the DAC8 send a signal to a powered sub? I'm trying to minimize my setup and replace my tube preamp, iFi Zen Stream and Chord Qutest.

 

[waynel]

This might be a silly question but can the DAC8 send a signal to a powered sub? I'm trying to minimize my setup and replace my tube preamp, iFi Zen Stream and Chord Qutest.

Of course it can , I use a MiniDSP studio for crossover then feed the digital inputs into the Okto dac8 pro. The Flex or NanoDigi will work too as will using a PC for crossover and feeding the Dac USB

 

[wav3form]

Of course it can , I use a MiniDSP studio for crossover then feed the digital inputs into the Okto dac8 pro. The Flex or NanoDigi will work too as will using a PC for crossover and feeding the Dac USB

So I could do the same with the DAC8 stereo? Sorry, I'm not that knowledgeable about hooking everything up.

 

[waynel]

So I could do the same with the DAC8 stereo? Sorry, I'm not that knowledgeable about hooking everything up.

Nope, stereo won't do it.

 

[Tom C]

Nope, stereo won't do it.

This is not accurate
The stereo version has two XLR outputs per channel, for a total of four. So you can indeed connect directly to a powered subwoofer, without need for a splitter. If the sub has RCA inputs only, you’d need a converter of some type, and adjust for the voltage difference.

 

[waynel]

This is not accurate
The stereo version has two XLR outputs per channel, for a total of four. So you can indeed connect directly to a powered subwoofer, without need for a splitter. If the sub has RCA inputs only, you’d need a converter of some type, and adjust for the voltage difference.

I disagree with your assessment. With the stereo Dac there is not a good way to high pass filter the main channels for proper sub integration. Digital crossovers are optimal and transparent.

 

[dualazmak]

In case your active subwoofer has low-pass/high-cut filter (and preferably gain/volume controller also) in it, you can also use the stereo headphone out of DAC8 Stereo (and DAC8 PRO) to feed into subwoofers, using TRS-to-RCA adaptor like this one. (ref. here on my project thread.)

In my DAC8PRO's Owners Manual, 1 can read;
Analog connectivity
Main outputs (back side)
8 x Neutrik gold-plated XLR connector
Output level: 4.1 V RMS differential full-scale
output impedance: 200 Ohms
Headphone output (front side)
6.3 mm (1/4”) TRS connector
Output level: 4.1 V RMS full-scale
120 mA linear output current
fixed to output channels 1 and 2
output impedance <100 mOhm

 

[waynel]

In case your active subwoofer has low-pass/high-cut filter (and preferably gain/volume controller also) in it, you can use the stereo headphone out of DAC8 Stereo (and DAC8 PRO) to feed into subwoofers, using TRS-to-RCA adaptor like this one.

You would still be lacking a high pass filter for the main channels which makes integration suboptimal and also difficult. The 8 channel dac costs the same and allows separate outputs for the mains and subs which can be used with an upstream digital crossover.

 

[Tom C]

I use powered speakers for mains with high pass filters built in, and my sub has low pass built in, so two channel isn’t a problem.
If I had mains that didn’t have built in high pass filters, I would use the natural roll of the mains to cross to the sub. That should work just fine.
I have a multichannel unit, so personally I skip the miniDSP and just use JRiver. Costs much less, takes less space and eliminates a set of cables.

 

[dualazmak]

You would still be lacking a high pass filter for the main channels which makes integration suboptimal and also difficult. The 8 channel dac costs the same and allows separate outputs for the mains and subs which can be used with an upstream digital crossover.

Yes, I myself do exactly what you are saying. Please refer here for my latest system setup with DAC8PRO.

 

[waynel]

I use powered speakers for mains with high pass filters built in, and my sub has low pass built in, so two channel isn’t a problem.
If I had mains that didn’t have built in high pass filters, I would use the natural roll of the mains to cross to the sub. That should work just fine.
I have a multichannel unit, so personally I skip the miniDSP and just use JRiver. Costs much less, takes less space and eliminates a set of cables.

Powered speakers with a built in high pass filter is a special case and in this case a stereo dac will be fine but it's unlikely that it applies to wav3form's system. Also, the HPF in the powered speakers is either digital or analog, if it's analog it's going to be noisier than a digital filter and if it's digital maybe you don't need a DAC at all.

 

[wineds]

Firmware version 1.6 and new DSP firmware incoming...

Spring 2024 Okto Research newsletter

 

[DWPress]

Here's a direct link to the github repository for the new AVDSP_DAC8.

I've been looking over the code and it seems pretty comprehensive with the ability to do the following on individual channels:

• crossovers with many different slopes - LR, Butterworth and more
• HP/LP, HS,LS
• Peek filters
• Delay (time)
• Attenuate

PEQ and allows for biquads as well. Only for PCM audio and up to 24/192.

NO GUI, hope someone makes one. If you think making .cfg files in a text editor is fun then you'll be ok.

This could potentially eliminate a lot of processing on my computer which is currently doing all of this via @mitchco's Hang Loose Convolver.

​

 

[gvl]

I have an early DAC8 prototype, in fact it’s the one that Amir originally reviewed here that ended up in my hands. It uses MiniDSP USB streamer for USB input, it’s XMOS based. Any hope the DSP code can be loaded on it?