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Okto dac8 stereo DAC Review

phoenixdogfan

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#81
Just add the nanoDIGI externally...it's not that big and easily tucked in out-of-sight behind the full size equipment. I am seriously considering this myself for the next setup.
Unfortunately will not accept USB which means a usb to spidf converter for anything coming out of the PC. Aarrghhh.
 

rvsixer

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#82
I was under the impression that the minidsp unit was not clean and would add some noise components even if in the digital domain from its legitimate processing as an unavoidable side-effect, so at best the combined effect would be the weakest of the two. If I am wrong in that assumption, happy to be corrected.
I assumed objectivity. Need proof, I have not been able to find any such dirt.
 

RichB

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#83

rvsixer

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#84
Unfortunately will not accept USB which means a usb to spidf converter for anything coming out of the PC. Aarrghhh.
Both a non-show stopper for me. I have SPDIF out on my music server, but will instead use my Topping D10 USB->SPDIF as its cheap and measures very well for this duty (bonus is my desktop headphone amp feeds off the D10, and has nice bit rate display too).
 

F1308

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#85
With a 64 bit digital volume control, many DAC's under $100 will still exceed the SINAD of any speaker amp available, when attenuated down to inaudible levels.
I see you can test everything in search of a top technical limit.
And you can search for the lowest price providing a performance that will be more than enough in a given technical chain...
Eyes wide open.
 

pozz

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#86
But SINAD is cumulative, right @pozz ?
Yup. Or anticumulative, subtractive.

Although I think @Sonic delight's point is that the amp is the weakest link. That's mostly true, but dongle can't drive an AHB2 to peak performance because of the former's weak output. Gain staging has be taken into account, as does accumulation of noise/distortion.
 

Vasr

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#88
I assumed objectivity. Need proof, I have not been able to find any such dirt.
I have made it my policy to ignore people that resort to ad hominems and/or snark. Life is too short. I was asking a honest question. So last response to you.

I think the assumption in this forum is that a unit has to be measured clean before it is assumed to be so rather than the other way around. On the other hand, I have read complaints in the minidsp board of noise associated with it for me not to assume that it is clean.
 

A Surfer

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#89
My question would be is any of this DAC performance (Ignoring the amplifier section) going to be audible versus any of the other extremely well measuring and far more affordable DAC options? At a certain point aren't we just at a ceiling effect anyway in terms of practical audibility? If somebody wanted a very clean sounding DAC and wanted to keep the price around $400 could they not get a DAC for that price that arguably would not sound any worse/different?
 

phoenixdogfan

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#90
Yes the only thing that matters is the SINAD coming out of the binding posts of the final amp in the system. That result will be identical from the binding posts of the Purifi or Benchmark AHB2 regardless if the $20 Meizu or the Okto DAC was used as a source.
Of course I couldn't download 5.1 decoded (any format off of JRiver) LPCM via USB from my PC, and still have two channels left over to receive LPCM via spidf from my A16 Realiser; thereby enabling me to send one set of signals to my Purifi/Hypex amps for 5.1 Surround sound over xlr, while the remaining two channels are sent to my THX 789 for 24 channel ATMOS emulation through headphones of any set of speakers I can get a PRIR for.

Don't think a $15 dongle will do that, do you?
 
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#91
Yup. Or anticumulative, subtractive.

Although I think @Sonic delight's point is that the amp is the weakest link. That's mostly true, but dongle can't drive an AHB2 to peak performance because of the former's weak output. Gain staging has be taken into account, as does accumulation of noise/distortion.
Put a $50-100 headphone amp after it and it can drive any amp to clipping.
 
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#92
Of course I couldn't download 5.1 decoded (any format off of JRiver) LPCM in USB from my PC, and still have two channels left over to send LPCM via spidf from my A16 Realiser to the remaining two channels enabling me to send one set of signals to my Purifi/Hypex amps for 5.1 Surround sound over xlr while the remaining two channels are sent to my THX 789 for 24 channel ATMOS emulation via headphonesof any set of speakers I can get a PRIR for.

Don't think a $15 dongle will do that, do you?
Might need to spend closer to $100 for that.
 

TimW

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#93
Hmmm... A trigger out, multiple SPDIF inputs, the ability to change the internal streamer firmware or disconnect it completely, and all in a nice aluminum enclosure. I really wish my miniDSP SHD had these features. Oh well hopefully there is an SHD version two with these features or an Okto with built in DSP. That would be my dream piece of kit.
 

Robbo99999

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#94
Because $20 gets you as good as it gets now. So not sure what the big deal is regarding this DAC. My measurements were conducted using the iPhone 7 as the audio source. Amir reviewed this one as well. I posted in his review thread of this DAC already today. From my computers my results were similar to what Amir got. From my 12' MacBook's USB C port running from batteries the SINAD was only -100dB. Goes to show how clean the iPhone is in comparison.
SINAD is cumulative rather than just thinking of it as a bottleneck, I remember seeing an online calculator that combined SINADS of devices to get theoretical final SINAD. But yes, there's a point where DAC quality becomes overkill, the exact point where that happens is debateable. But you for sure can be happy with your iphone & quality dongle.
 

phoenixdogfan

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#95
Both a non-show stopper for me. I have SPDIF out on my music server, but will instead use my Topping D10 USB->SPDIF as its cheap and measures very well for this duty (bonus is my desktop headphone amp feeds off the D10, and has nice bit rate display too).
Actually my old IFI IDSD Micro does that as well. Don't know if it does it quite as well as the D10, but it certainly does do it. (Along with damn near everything else including charge my phone.) :p
 
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#96
SINAD is cumulative rather than just thinking of it as a bottleneck, I remember seeing an online calculator that combined SINADS of devices to get theoretical final SINAD. But yes, there's a point where DAC quality becomes overkill, the exact point where that happens is debateable.
I can use the Meizu DAC and my iPhone as a source to drive any amp on the market, and match the specs at the amp binding posts that Amir will achieve from his AP 555 analog outs driving the test signal. In other words it's possible to achieve as good of measured performance as is achievable from any speaker amp, from a $20 dongle DAC as the source.
 
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#97
My question would be is any of this DAC performance (Ignoring the amplifier section) going to be audible versus any of the other extremely well measuring and far more affordable DAC options? (...)
Probably not. But why ignore the amplifier section? If a company, like Okto Research, puts tremendous effort in extracting the maximum performance of a given DAC chip (in this case the ES9028Pro) would it neglect the amplifier section and power supply? Theoretically, still possible, but I don't think this is the case here. Quite the contrary. And no, not all DAC's sound the same!
 
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A Surfer

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#98
Probably not. But why ignore the amplifier section? If a company, like Okto Research, puts tremendous effort in getting the maximum performance of a given DAC chip (in this case the ES9028Pro) would it neglect the amplifier section? Still possible, but I don't thinks this is the case here. Quite the contrary. And no, not all DAC's sound the same.
Well, unless the analogue output stage is deliberately colored, or there are unintended design mistakes made anywhere in a DAC, as long as the thresholds are kept below audibility, how can a DAC sound different? The amp performance does seem decent for sure, but I rather doubt many will be buying it for the amp section. I am not attacking the clearly excellent effort and results, just questioning why people need to spend this much.
 

rvsixer

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#99
I have made it my policy to ignore people that resort to ad hominems and/or snark. Life is too short. I was asking a honest question. So last response to you.

I think the assumption in this forum is that a unit has to be measured clean before it is assumed to be so rather than the other way around. On the other hand, I have read complaints in the minidsp board of noise associated with it for me not to assume that it is clean.
I apologize you took this way, it was not meant as snarky and agree life is too short. I simply saw a device being cited as problematic based on assumptions, and called for clarification/proof.

MiniDSP devices have indeed been tested and some found to have noisy *analog* sections (both here and other objective sites), but none indicating the *digital* sections are noisy to the point of audible artifacts. The only thing I have found is possible ASRC issues (but again, no proof that I have been able to find, only more subjectivity/assumptions that somehow become "fact").

I myself would love to find out before spending big Okto bucks.

Best.
 

Robbo99999

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I can use the Meizu DAC and my iPhone as a source to drive any amp on the market, and match the specs at the amp binding posts that Amir will achieve from his AP 555 analog outs driving the test signal. In other words it's possible to achieve as good of measured performance as is achievable from any speaker amp, from a $20 dongle DAC as the source.
I suppose you could prove that by plugging the SINAD numbers of your dongle & amp vs the DAC in this review combined with the same amp. You'd plug the numbers into the calculator at the bottom of this page and compare the result:
http://www.sengpielaudio.com/calculator-thd.htm

EDIT: that's not SINAD at my link there, but I seen SINAD calculators somewhere.
EDIT#2: actually you can use that calculator for SINAD, just put in negative numbers.
 
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