More info on the intona

[foxesden]

Hi

Just spent the day measuring my DAC as I thought it was losing bass.

I was using rightmark, and only wanted to confirm whether the frequency drop I was hearing could be measured - it could. But, I was surprised at how bad the noise etc was. So I tried measuring my other main DAC April Music Eximus; and this too didn't measure too well.

So I suspected my USB soundcard ESI U24XL wasn't too good; and bunged the intona into the chain to see if it made a difference. Here are the results





This result was entirely repeatable.

I suspect that it is because the old ESI device which is quite old has a ropey USB interface.

Jonathan

[drmatt]

Can't read the text in your attachment, it seems to be 102 bytes in size! (Though this may be Tapatalk screwing things up..)


Transcoded from Matt's brain by Tapatalk

[Archimago]

Hi

Just spent the day measuring my DAC as I thought it was losing bass.

I was using rightmark, and only wanted to confirm whether the frequency drop I was hearing could be measured - it could. But, I was surprised at how bad the noise etc was. So I tried measuring my other main DAC April Music Eximus; and this too didn't measure too well.

So I suspected my USB soundcard ESI U24XL wasn't too good; and bunged the intona into the chain to see if it made a difference. Here are the results





This result was entirely repeatable.

I suspect that it is because the old ESI device which is quite old has a ropey USB interface.

Jonathan

Interesting... Wondering if you'd get better results with that ESI USB ADC in 24-bit recording mode.

Looks like there's some noise there, but you mentioned bass loss issues. Did you actually find frequency response differences?

Bottom line is that it looks like you need a better ADC than the U24XL which I think is only 1/2 the price of the Intona USB isolator! The other question is what computer / laptop are you connecting the ADC to...

[foxesden]

Thanks for getting back.

Yes I realise the ESI is well out of date and only a basic USB sound-card (The irony is that I used the ESI to transcribe much of my vinyl); but I was learning how to do the settings in RightMark and getting some dubious results with the onboard soundcard. I am not sure how much I would want to spend on a better ADC, now that I have a feel for what you have gone through with all that testing! I spent a day on it, and could easily see my self getting more obsessive about trying out new measurements.

It is tricky to do, as setting the output volume to the max seems to overload the ADC and causes huge distortion figures, whereas have the output to low and the noise looks terrible.

The PC is a 2016 desktop based on an ASRock Fatal1ty Z170 Gaming K6 Skylake ATX Motherboard (supposedly with an audiophile dac built in). PSU is EVGA SuperNOVA 750W PC Power Supply - Gold.
Intel Skylake i5 CPU & Radeon Graphics Card both water cooled. SSD / HDD. In a fractal design r5 case. Plus a number of fans.

I have not attempted any audio tweaks or other additions other than to make it quiet.



I did manage to track down that there was a bass roll off on the Audio Note Dac - which was about -3.5 db down @40hz.

I found that a twisted silver cable ameliorated this by 1 db. But all other cables tandy gold (cheap), audioquest ruby (mid) and silver foil (home made exotic) were pretty much identical. Within the limits of the ADC - which we have established is mediocre.

[Julf]

I suspect that it is because the old ESI device which is quite old has a ropey USB interface.

I find it very strange that even stereo crosstalk would be affected. You ran RightMark in loopback through the inputs on the ESI? My experience with RightMark is that it gets easily thrown out by any ground loop noise.