Okto dac8 stereo DAC Review

[MadMan]

So I need to ask for 9.8 volts for my AHB2 to reach maximum output...Thank you.

The AHB2 has 3 (I believe) input gain stage settings. 'Consumer' level, 'standard pro/studio' level, and 'super low noise/use with high output Benchmark DAC' level. The performance of the AHB2 increases going from the first to the last, so you should read the AHB2 manual to determine what Okto DAC output to request so that you can use the 'super low noise/use with Benchmark DAC' setting.

 

[F1308]

9.8V is 22dBu. I think the AHB2 can accept up to 24dBu or 12.3V. (Both line levels are typical for pro equipment).

No idea....I just was told by the manufacturer himself that maximum output will be reached at 9.8 volts.
No idea about the consequences of asking for 12v as the customized output and then using it at full volume to the AHB2...
I guess I better limit the maximum output knowing that at full volume a 100% power is reached...and not any more.

 

[F1308]

The AHB2 has 3 (I believe) input gain stage settings. 'Consumer' level, 'standard pro/studio' level, and 'super low noise/use with high output Benchmark DAC' level. The performance of the AHB2 increases going from the first to the last, so you should read the AHB2 manual to determine what Okto DAC output to request so that you can use the 'super low noise/use with Benchmark DAC' setting.

I know, thanks ...
The manual says...
Set this switch all the way down if you are using professional balanced sources.

I understand then that a customized 9.8 volts output at full volume brought to AHB2 with its switch selected to lower position and XLR cable is the best choice.

 

[Labjr]

So nice to read!
This very DAC, Pavel and his colleagues were here:
https://www.sunshipaudio.com/2020/02/okto-dac8-stereo.html
Great DAC, great people.
View attachment 73401

1,100 Euro Best In Class DAC with 58,000 Euro speakers! Time to work on affordable, high performance speakers!

 

[Billy Budapest]

How are the XLR’s wired—US standard configuration or EU standard?

 

[RichB]

I know, thanks ...
The manual says...
Set this switch all the way down if you are using professional balanced sources.

I understand then that a customized 9.8 volts output at full volume brought to AHB2 with its switch selected to lower position and XLR cable is the best choice.

I suppose that depends at the distortion and noise profile for each component.
I suspect the Okto does very well, but I have seen components that can output 9+ volts at higher distortion.
For these products, a higher gain from the AHB2 would be a better choice.

I run an Oppo UDP-205 at 4 volts into the middle AHB2 gain and like this because it provides the best performance and also sets a safe maximum volume.

- Rich

 

[Billy Budapest]

BTW, here is a glimpse of the interior, from Sunship Audio’s website:

 

[F1308]

1,100 Euro DAC with 58,000 Euro speakers! Time to work on affordable, high performance speakers!

Yes, please, DO.
I have my synthesizer keyboard, my DAC, my amplifier...time for loudspeakers !!!!

 

[MadMan]

I know, thanks ...
The manual says...
Set this switch all the way down if you are using professional balanced sources.

I understand then that a customized 9.8 volts output at full volume brought to AHB2 with its switch selected to lower position and XLR cable is the best choice.

Page 23 of AHB2 the manual:

Input Sensitivity
 Low-Gain = 22 dBu (9.8 Vrms)
 Mid-Gain = 14.2 dBu (4 Vrms)
 High-Gain = 8.2 dBu (2 Vrms)
 Use Mid-Gain or High-Gain settings for unbalanced inputs  Unbalanced inputs require RCA to XLRM adapter cables

So yes, 9.8Vrms would fully drive the AHB2 with its low-gain setting. You may want to consider a more industry-standard setting, Benchmark's own DAC 3 with a full scale 0dBfs digital signal has a 'factory calibrated bypass' level of 24dBu (12.3Vrms) and a maximum of 27.5dBu (18.4 Vrms), and they have -10dBu and -20dBu attenuator pads for gain-staging compatability. Someone else could chime in, but I would think if you're getting a custom output, you should probably get 0Vrms-12Vrms range so your Okto DAC wouldn't be unusual when used with other gear.

 

[F1308]

Page 23 of AHB2 the manual:

Input Sensitivity
 Low-Gain = 22 dBu (9.8 Vrms)
 Mid-Gain = 14.2 dBu (4 Vrms)
 High-Gain = 8.2 dBu (2 Vrms)
 Use Mid-Gain or High-Gain settings for unbalanced inputs  Unbalanced inputs require RCA to XLRM adapter cables

So yes, 9.8Vrms would fully drive the AHB2 with its low-gain setting. You may want to consider a more industry-standard setting, Benchmark's own DAC 3 with a full scale 0dBfs digital signal has a 'factory calibrated bypass' level of 24dBu (12.3Vrms) and a maximum of 27.5dBu (18.4 Vrms), and they have -10dBu and -20dBu attenuator pads for gain-staging compatability. Someone else could chime in, but I would think if you're getting a custom output, you should probably get 0Vrms-12Vrms range so your Okto DAC wouldn't be unusual when used with other gear.

I keep my eyes wide open.
And open to all your nice help.

In the mean time, another mail from Benchmark came...

I wish you would consider our DAC as I believe it to be a more reference product. But I understand. According to their site, the XLR outs are 4.1V RMA full scale. So, I would put the AHB2’s sensitivity switch in the middle position. If you go for the custom output voltage, then the lower position would be the one.

 

[Kal Rubinson]

I run an Oppo UDP-205 at 4 volts into the middle AHB2 gain and like this because it provides the best performance and also sets a safe maximum volume.

According to their site, the XLR outs are 4.1V RMA full scale. So, I would put the AHB2’s sensitivity switch in the middle position.

Yes and the DAC8Pro works well that way, too.

 

[F1308]

Yes and the DAC8Pro works well that way, too.

Mmmmm....that maximum volume seems to be set by your ears, because according to the manual, raising the switch increases the output...

If you are using an unbalanced input, you must use one of the top two switch positions.  If you are using a balanced input, you will usually need to use one of the bottom two switch positions.  Set this switch all the way down if you are using professional balanced sources.  Raise the switch to increase the output level.  Lower the switch to decrease the output level.

So in the middle position you get higher volume and you will refrain yourself of any further increase...
But what if volume goes accidentally to maximum, blame that little nice toddler touching everything...?
It would be safer the lower position... wouldn't it?

 

[Kal Rubinson]

Mmmmm....that maximum volume seems to be set by your ears, because according to the manual, raising the switch increases the output...

In my house, the maximum volume is always set by my ears (if my wife's away) but the maximum available volume exceeds that with this setting.

But what if volume goes accidentally to maximum, blame that little nice toddler touching everything...?

My grandkids are no longer toddlers and no one touches my gear but me.

It would be safer the low position... wouldn't it?

Not an issue. (See above.)

 

[F1308]

In my house, the maximum volume is always set by my ears (if my wife's away) but the maximum available volume exceeds that with this setting.

My grandkids are no longer toddlers and no one touches my gear but me.

Not an issue. (See above.)

Enjoy....

I am still thinking about the next step.....your great-great-grandkids turning it fully up.

https://play.google.com/store/apps/details?id=io.github.sharmanirudh.thresholdsounddetector

 

[TimW]

@Okto Research Great job on your Okto dac's! I don't suppose that OktoSHARC is still available anywhere?

 

[MC_RME]

I expect that RME has more headroom for intersample overs than Okto. So SINAD number is not a whole story...

EDIT: Hmm, I could be mistaken. It was Benchmark who claimed 3.5 dB of headroom above 0 dBFS for intersample overs for their DAC3.

Indeed the current DAC and Pro have 4 dB of intersample peak headroom. For the unit reviewed here you have to ask Okto Research. ESS chips usually have 0 (zero) ISP headroom, unless one trades SNR against ISP (by attenuating the digital signal, as done in the Oppo 205). But that doesn't change the outcome, the DAC8 Stereo can still reach a higher THD+N value.

 

[gvl]

Very dry sound, i'm tired from that dac, sold it.
How does it sounds is not interest to anyone in this forum. Only measurments!

You smell like a troll.

 

[countbasey]

Are there any measurements of this used as a roon endpoint which would be my configuration to replace my Lumin. I saw someone mention that its Pi interface to USB would degrade performance (jitter) but not sure which measurements in the review would show this. Maybe similar to Toslink and not a concern? thanks.

 

[DaaDaa]

You smell like a troll.

we just found our chief smelling officer

 

[Veri]

Indeed the current DAC and Pro have 4 dB of intersample peak headroom. For the unit reviewed here you have to ask Okto Research. ESS chips usually have 0 (zero) ISP headroom, unless one trades SNR against ISP (by attenuating the digital signal, as done in the Oppo 205). But that doesn't change the outcome, the DAC8 Stereo can still reach a higher THD+N value.

Thanks for chiming in