Audio measurement gear

[MC_RME]

We could do the digital part, but not the analog one. You would be forced to split your input signal and apply it to both input channels. Therefore we have no plans to add such a feature, sorry.

Well, I have to eat my own words. In the upcoming firmware for the ADI-2 Pro (maybe end of this week) we added the M/S-Processing option also to the analog inputs. The M simply means mono of both input channels to the left recording channel. And therefore does exactly what you wanted to have: SNR rises 3 dB to about 123.x dB rms unweighted, no negative influence on phase or frequency response. Pretty cool to play with if you have split cables...

 

[Rja4000]

No it wasn't summed. I have actually broken the board I had a while. I dropped a screwdriver on it

Basically the data sheet doesn't exaggerate, it's 108dB thd + n at - 1dBFS.

I will have to go back and try to get those missing 3dB then...

 

[Rja4000]

By the way, I'm trying to use separate sampling frequencies for DAC and ADC with Virtins Multi Instrument but I didn't succeed so far.

I want to do that to get the 90kHz bandwidth THD vs frequency like Amir.

I can do it by running 2 separate instances, but I don't understand why it doesn't work with one.
And with 2 instances, it works once in a while... and never starts from my .Net app...

I love this tool, it's so comprehensive, but there are some really annoying caveats...
For $200, it's still a crazy value though..

 

[Rja4000]

Well, I have to eat my own words. In the upcoming firmware for the ADI-2 Pro (maybe end of this week) we added the M/S-Processing option also to the analog inputs. The M simply means mono of both input channels to the left recording channel. And therefore does exactly what you wanted to have: SNR rises 3 dB to about 123.x dB rms unweighted, no negative influence on phase or frequency response. Pretty cool to play with if you have split cables...

Did I told you already?
You guys are the best!

 

[jfetter]

Great article!

I looked at Schiit site a while back and was caught off guard by the company attitude.
Don't like flying but gotta go to the store.
I totally relate to the business model.
The was a time when other audio mfgrs had similar manafestos ie Sansui. 60s-70s...
The #1 engineering criteria was 'how does it sound'.

 

[eliash]

That 'phenomenon' is not limited to the AK4490, or AKM at all. I found it nearly everywhere. The level to see it varies, and of course it is easier to find with low noise DACs. On most chips noise covers these effects so no one ever noticed them. That said the better the DAC's SNR the easier these tones become visible. Try the AK4499, no averaging needed to see them clearly.

The reason behind it we can only speculate. A request at AKM went unanswered.

clock jitter (on-chip)?

 

[Phos]

This seems along the same lines enough for this thread:

Was putzing around with having RMAA test a TOSlink loopback on my X-Fi, and did a test at 44.1 KHz by accident, but when I reran it at 96 KHz I noticed that IMD was much lower on the 96 KHz test. Does TOSlink jitter show up as IMD? Thinking that having a higher carrier frequency might be shrinking the error.