Soekris DAM1021 R2R DAC Measurements

[rebbiputzmaker]

Hi

I do understand the difficulty of a blind test but it would be interesting to compare some R2R to other kind of DAC in a blind tests. I understand their unpracticality and their difficult logistics but ...
I am very hesitant to come to term that all DAC when competently designed sound the same ... It could be the remnants of my long audiophile conditioning ... Same with amps BTW

Excellent point.

 

[Jinjuku]

FWIW, this guy has some Pacific Microsonics (AD only?) in his chain. Pretty impressive list of customers:

http://magicgardenmastering.com/

So probably not much?

 

[Rene]

So probably not much?

I went back to Magic Garden's site and looked through all the album covers. Continuing below this to the Studio heading, if you look below his work table on the floor to the right you will see the PMI box! Funny he doesn't mention it in his equipment list. There he mentions the Bricasti, which he apparently uses as his D-A. So he must feel that the Bricasti sigma-delta is better for playback, even though it doesn't do HDCD decoding.

I like his p-p 211 amps.

 

[Deleted member 65]

This studio in Stockholm has three rooms, all equipped with Pacific Microsonics HDCD A-D D-A Converters Model 2 and Model 1

http://cuttingroom.se/our-studios/

 

[Wombat]

Some objectivism please. Performance credentials. Comparisons. Ugh.

 

[March Audio]

A small update to the measurements. I was concerned about the mains pickup I observed, 50hz and harmonics. I assumed this was a measurement issue or an issue with the diy build, but could not identify any problem.

I took a look at measurements of the Soekris dac1541 on sbaf. It appears they show a very similar problem, 60hz in their case. There is a difference in fft resolution, but the same issue is obviously there. So it looks as if it is a dac related issue.

Me

Sbaf

 

[March Audio]

Also, although there was some conjecture regarding the dacs linearity, sbaf measurements show similar deviations,

 

[amirm]

Yes indeed. The measurements on SBAF use that too large of a scale (+20, -10 dB) which artificially flattens the curve making it look like linearity is excellent.

 

[March Audio]

Yes indeed. The measurements on SBAF use that too large of a scale (+20, -10 dB) which artificially flattens the curve making it look like linearity is excellent.

Indeed. Im also a bit confused why Soekris thought sbaf meadurements showed the dac to be linear "down to -140dB".

 

[amirm]

Left side of their graph is at -140 dB and due to scales being wrong, it conveyed that wrong impression to him. Looks like there is 2 dB of error in their measurements at that limit.

Then again I am not sure the Prism Sound analyzer they are using is accurate to that level itself.

BTW, I sent a message to him asking for evaluation unit but never heard back.

 

[soekris]

Indeed. Im also a bit confused why Soekris thought sbaf meadurements showed the dac to be linear "down to -140dB".

First, Amir's definition of level linearity is that over 0.1 dB level deviation is failure, which is just 1% level deviation, which can be affected by all kind of things, probably especially noise, but also measurement equipment.

What I really noticed was atomicbob's post #19 where the dac1541 -140 dB signal is still visible at -140 dB, how close to -140 dB is hard to see, but I would say it's pretty good, especially when compared to another R-2R DAC....

Some measurement, not just the dac1541 but also others, are disturbed by mains noise, and mains noise can come from many things, especially when we're looking at that low signal levels. And then there is the issue of balanced connections, there seems to be several ways of doing it, and it seems like that audiophile equipment is not doing it the same way as professional equipment, partly to be compatible with single ended signals....

You have to carefully evaluate measurements, t.ex. many people believe that R-2R DACs distortion of 0.01% is way to high, yet they listen to speakers with 1% distortion.... I would say that pure harmonic distortion is not that important, the problem is with non harmonic distortion, and some of those we haven't figure out how to measure, that's why most delta sigma DACs are described as "harsh", even when they measure perfect....

I do know this site is really about measurements, but you should listen to the devices under test too.... But it will then take way more time....

 

[soekris]

Left side of their graph is at -140 dB and due to scales being wrong, it conveyed that wrong impression to him. Looks like there is 2 dB of error in their measurements at that limit.

Then again I am not sure the Prism Sound analyzer they are using is accurate to that level itself.

BTW, I sent a message to him asking for evaluation unit but never heard back.

I will make an unit available to you, are just considering which one, are thinking about the dac1421 which I will have first production units of soon....

 

[Cosmik]

that's why most delta sigma DACs are described as "harsh"

By whom?

 

[amirm]

I will make an unit available to you, are just considering which one, are thinking about the dac1421 which I will have first production units of soon....

Thanks. Whichever one you want me to measure would be fine. Newest one seems like a good option so that the data doesn't go stale too fast.

 

[rebbiputzmaker]

By whom?

People who listen and have heard the difference.

 

[Wombat]

Or people who listen and think they hear a difference. It is usually personal opinion or rhetoric. I would like the claims substantiated by the subjective claimants in order to end the dancing around the topic.

 

[Cosmik]

People who listen and have heard the difference.

How does that make this forum or thread any different from any standard 'subjectivist' 'review' of audio hardware? Almost everyone reading your statement above is thinking the same thing: what we "hear" is subject to bias, but they've pointed it out so many times they are weary of it. You must surely realise that.

 

[Wombat]

I think the rabbi is working in the repetitive/last-man-standing argument tradition. It doesn't cut it here, fortunately.

 

[rebbiputzmaker]

How does that make this forum or thread any different from any standard 'subjectivist' 'review' of audio hardware? Almost everyone reading your statement above is thinking the same thing: what we "hear" is subject to bias, but they've pointed it out so many times they are weary of it. You must surely realise that.

You can listen in a controlled test environment. Eventually listening should be done in some way, shape or form. Are they audio devices???

 

[Wombat]

You can listen in a controlled test environment. Eventually listening should be done in some way, shape or form. Are they audio devices???

And you have done this or can reference reliable such tests to back up all of your subjective claims here?