Secret project (Svart AD/DA converters)

Well when you mix to a console it doesn't really matter that a converter adds or takes away. We manipulate the signal post conversion anyway so color might be a good thing. However, I would think mixing ITB, one would want sterile.

But you know I think getting to know whatever converter you use is more important than anything. Jumping from one to another makes little sense to me. Same with monitors, wives etc...

Hey thanks for your feedback!

I do have to address a few things though, and folks are free to interpret them as they will.

I see that Tony edited your post.  Not sure why he would do that..  Anyway..

"No volume control, meaning you have to own a monitor controller. Who is your target audience? Dudes with MOTUs, RMEs or Presonus's, or dudes with Consoles and monitor controllers?"

I use my software to adjust the levels digitally before the output, and my DAC goes straight to my amplifier.  In this day and age of interfaces, I don't even know why folks use analog monitor controllers, they are just another level of possibly messing up the analog signal to the amplifier.  I'd personally avoid them whenever possible.


"I was unable to clock the symphony's SPDIF in to the ADC on this unit, as is how it normally works. SPDIF Transmitters are the master clock source (which doesn't make sense, because the symph would always be the Master for outbound audio, and another device would be the master for inbound. shouldn't one device control the clock for all connected devices?)"

SPDIF transmitters are ALWAYS the master to the receiver.  The Symphony would be set to be a slave to the incoming SPDIF ADC signal.  The Symphony would simply pass the clocking through to the DAC when set like this, and look like the master to the next device.  If it does not, then it violates the AES/SPDIF protocol standard.  


"if you fix the bottom end (both dan duerloo and jim williams told you how to do it, you should probably listen to what they're saying, since now i'm the third person to say it doesn't have any bottom)"

Dan made some suggestions and I greatly appreciate his testing work, but I've not heard anything from Jim as he hasn't tested a unit (not sure where that came from), but anyway, I have a couple people saying that it lacks bottom compared to known hyped units..  I also have some others saying it's perfect the way it is.  I also have some audiophiles listening as well (you didn't think that you guys were the ONLY ones testing units did you?) and so far just some suggestions from them.  I have frequency sweeps of my own showing that it's essentially flat down to almost 10hz.  I've honestly found no electrical reason why anyone should think it's excessively light on the low end.  In fact, the DAC is completely DC coupled from the DAC chips right through to the TRS connectors.

Another thought is that you've set your speakers, room and listening position based on the symphony's output.  You've "tweaked" and "tuned" for best performance with the symphony.. Any other converter dropped in place of the symphony would essentially require redoing most of that for optimum frequency response.  This is one of the caveats of doing testing without controls, like this.

So, here's the quandry..  What do I do?  Even your sine sweeps show almost the exact same low end rolloff point on the graph for each converter(which seems really high considering)..  However, if you look very carefully, you'll see that the symphony slowly drops in level as it goes up in frequency.  Judging by the graph lines, it drops by 1dB or so, which is enough to make it seem more hefty on the low end.  I think if anything, I think you've proven that the symphony does indeed live up to it's reputation as low-end heavy.  So based on that, do I proceed to modify my unit to please a couple people, or continue on as planned?

I don't know, but I will say that it's valuable information nonetheless.  I'm still considering all opinions no matter what, and your's matters just as much as anyone else's.


"fix the width/stereo image things"

These things are a function of the input signal, and the hardware receiver/DAC chips.   My units use dedicated DAC and SPDIF ASIC chips so the signals are handled only in hardware, not software.  Since each output is it's own separate circuit, there isn't anything between them that would smear or otherwise cause issues between the outputs.  I feel there isn't much I can do to the circuit for this besides add some longer lines between the DAC IC's to introduce false delay for some HAAS effect.  However, since I took great pains to ensure that trace lengths were equidistant for each DAC chip, for superior propagation delay matching from the receiver to the DAC chips, I'd say that it could possibly only seem like an issue since you only have the symphony to compare.  Which is correct?  It's anyone's guess, but I'd wager that since the Symphony wouldn't let you clock from the SPDIF input, which is a fundamental error in implementing AES/SPDIF, I have to wonder about their implementation of SPDIF in general.  I'll look into all options on this and see if there is anything that can be done.



But overall, thanks for your efforts.  I'm still investigating every opinion that everyone has mentioned to me, and hope to have a conclusion soon. 

Seems a bit of paranoia going around these days? I edited nothing of his content or analysis, just some simple language, and I PM'd chuck that I did so.
Svart, Like I said before, i'm routing for this to work for you, taking advice from everyone who's put the evaluation in, including Jim(even blindly) is a very good idea, he has been part of the some pretty damn famous ADDA designs.

Concerning the stereo width, have you done a crosstalk test on this? I'm sure it's probably very good, but i'm curious, i'd see what it looks like @10k. It's normal to do a LOT of listening tests, and expect plenty of tweaking as parts of identical values do indeed sound different from one another as i'm sure you know.

one other thing you may consider is swapping out all of those SMD electro's(there are only 12 per board or so, no biggie at all), IME they NEVER sound good, i know they are not in the audio path, but ime it doesn't matter, if they were to be replace with the top notch through hole stuff(even surface mounted with short bent leads), and even though it would look identical on a analyzer, i'd bet my last dollar that it would change the sound for the better.... JMO and trying to help, I think you are dangerously close to having one of the best boxes out there, keep pushing it and you will own this market at your price point!

I'm just confused by the "lack of stereo width" comment. That is absolutely the opposite of my experience. Plus, I think it's confusing when you say it "lacks" bass. That might give the impression there's something wrong with it. It is lighter on the bass than the symphony, yes. But you've had four people tell you that the symphony is colored and has an exaggerated bottom...and to say, "doesn't have any bottom" just makes me roll my eyes.

re: the monitor controller, It sounds like you're using your unit not as an audio interface, meaning you can't play music or youtube videos on your computer thru the converter. Even tho I use the symphony as my converter, it's also what I use to listen to everything coming out of my computer. System Preferences -> Sound -> Output ->Default Device: Symphony I/O.

The sweeps i made don't show an exaggerated bottom.  up until about 7k, both units have identical frequency response, so explain that, mr. science lol    Please explain to me how, if i'm going out the analog outputs of the symphony into the analog inputs of the symphony and getting a flat response, it has an exaggerated bottom end.  

I dunno, but if you look at the graphs you posted, you can see that the "symph" graph shows that the response goes down as frequency goes up.  It's very slight, but you can see it, probably by about 1dB or so.

Also, the sweeps you show don't show a lack of bass on my box either!  It does show that it's a couple dB louder though.

I mean, it looks like we have a quandry here.  Your graphs don't show that the Symphony has excessive low end, but they also don't show that mine lacks low end.

How could this be?  Thoughts?

Wtf?