Me 3. The current version rocks. Thank you for asking for ideas from owners. That is refreshing.
MrDerrick said If I adjust the level of the channel that is not at 0, sometimes the balance control will lock up and I have to reboot.The balance control is a bit weird, but the DS certainly shouldn't lock up. I suspect that the balance isn't locked up and that some combination of volume up/down, readjust balance, volume up/down, readjust balance... will get things back to normal. If not, please report an exact sequence of volume/balance control that cause a lock up and we'll get it fixed.Might it be possible to do away with having a low and high setting on the same software?
And instead offer high, medium and low gain software?
Perhaps a separate mute for each channel would help you, but I think it’s more likely to confuse the typical user. Perhaps we can think of a way to do it (like only muting or unmuting the lowest channel if you press mute while using the balance control?)
The high range vs. low range is a hardware 20dB attenuator implemented with a relay controlling a resistor shunt to ground. It won’t be changing without some soldering 
The volume control is pure software in the FPGA.
I do find it odd now 4 find it not warm it clearly is but I do very much accept other views
Also reds view on the pcm and dad
It’s all conjecture from most but Ted is way above that
Ted as I have said before dinner on me a d off to my office rig to listen
Of drink of choice of course
Al
Ted, I’ve been reading through this and pondering. I like the idea of a display tweak that would show resolution / bit depth in a larger font. In general though my feeling is that we (I) don’t want you to “tweak the sound” of the DS. Find and fix bugs, maybe figure out if a filter or two can be added without ruining the existing sound, maybe figure out if there’s a way to reduce distortion and improve effective bit rate even further. IOW, bias the work toward getting even more of the DS “out of the way” of the transfer of music from input to output, if that makes any sense. Ideally you’ll figure out how to “fix” every single remaining thing and maybe add one or two new features. Whatever the sound is at that point is the sound. If we don’t like it (I suspect that won’t happen
) then it’ll be time to move on to a new DAC. Sounds rough but I’d rather have the development of the DS FW continue along this engineering line rather than a more subjective line. Seems like it’s worked pretty well for us so far.*
*Of course as we have seen during beta testing, simple recompile decisions can sometimes have an affect on the sound. Variables like this aren’t part of my rant, although if there were a way to characterize how these choices wind up changing the sound, that would be great.
Happy New Year!
Excellent thinking, Tony.
The DS, but ever so much more so.
No, Tony I’m right with you. All of the sound tweaks I’ve been thinking about are purely FPGA compile hell or trade offs among technically equal implementations, not SQ sculpting for sculpting’s sake.
I just want to entertain any suggestions I can and look for opportunities to make things better technically. Like I mentioned earlier if it would take doing something that’s wrong or only 1/2 way done technically to achieve a particular sound I’d shy away. I’ve been pleasantly surprised that none of the technically correct decisions have detracted from the sound and many (most) resulted in better sound. And conversely when I started I was afraid I’d have to tailor the sound to compete with some DACs, but that hasn’t turned out to be the case. I don’t like the fact that the best we can do about FPGA output jitter at the moment is to compile up a bunch of identical implementations and then listen and subjectively pick the best result (and I think I’ve figured out ways of lessening this effect with new hardware), but we have to continue the painful listening process for new DS FPGA releases.
In general the tweaks I’m thinking about are differing implementations of mundane things. Decoding S/PDIF, doing processing of audio channels in series or in parallel, detecting the current sample rate, etc. They are all technically correct but they often make a difference in the noise/jitter introduced into the rest of the system and we have to (get to?) pick the ones that sound the best.
It’s important to remember that for better or worse there’s not a most technically correct upsampling filter, if there were I’d use it. Like the Heisenberg’s uncertainty principle there’s a trade off in digital filters between excellent frequency response and excellent time response and it’s purely a subjective decision where to be along that spectrum. (Or more properly we don’t have accurate enough models of human hearing to be able to optimize the frequency/time tradeoffs for best perceived sound.) I’ve been guided by my belief that accurate transients are the most important, but that’s an (informed) assumption.
Similarly there’s no good mathematical model of sigma delta modulators. I have to choose among those that have acceptable frequency/time response the ones that are the cheapest to implement or the ones that react the best with out of range inputs, etc. It’s still an art balancing the many tradeoffs in implementing SDMs and therefor some of my work will be modifying or reimplementing parts of the SDM in the DS to achieve better sound. Anything I learn empirically or from the literature will be useful in the DS and any other DAC I build.
I do not want to start a new thread and thought that this thread may fit my question. What happens to the firmware code when the DS is off and then it is re-initialised. My DS stops from time to time as if the DS is frozen and the only way to get it going again is to re-intialise. When I do the re-intialisation, sometimes I am reasonably certain there can be a noticeable change in the SQ. Enough change to be readily obvious. Sometimes it is better than before the re-intialsiation, sometimes the same and sometimes less so.
Could this be the case? I do not think it is imagination or placebo because there are times when it is quite profound and nothing else has been changed except off and on with the back rocker switch. The amp is on and the server is still playing. I understand that my system is very accurate and it is possible to hear small differences. The change seems to be in the treble. Could this be so?
This post is not at all about the DS stopping. That is a problem that will be fixed. It is just work in progress. Can re-intialistion change the SQ?
John
assisi said Can re-intialistion change the SQ?Yes, turning the DS off for even just a few seconds and turning it back on changes the sound quality more than you might expect. Before we realized that it made A/Bing of different versions of the code sort of hit and miss. If the FPGA freezes (which I haven't seen except for power supply problems) then there will be DC current going thru the output transformer. Degaussing the transformers in that case will take some playing time. I suspect that when you turn off the DS since the digital power supply dies faster than the analog supply that there's a short time where the FPGA is frozen but the analog is still working so you end up with a DC current thru the transformer for a short amount of time. Fortunately the DSD output for a zero (or muted input) is the best signal for degaussing the output transformers.
I don’t have John’s problem but would playing degaussing tracks get him back to normal even more quickly?
Ted smith. Can you post a link to file to cleanse the DS after reboot.
Also is there anything that can be done on your end about this. ?
I have a special ‘burn-in’ track I can put on DropBox for those interested.
PM me if this interesting.
There’s no permanent problem and as I said just playing nothing (source paused) will clear it up. A degaussing track is also fine. Break-in noise tracks will also “shake things loose.” Unlike tape players/recorders the output transformers are always heading towards clean so time is all it takes. I can hear a big difference in just the first few minutes and for A/B testing we’ve been recommending 10 to 30 minutes.
Don’t get paranoid: relax for a few cuts and things should be back to normal.
Ted can you explain what chages in general. And about how long for paused play. As I have compared firmwars and a reboot is a must.
Al
Howdy Al
I thought I did explain what changes 
Tho I expect that most people would describe the change in sound differently, for me it’s a slight loss of detail and pace. It just doesn’t make you want to move as much or draw you into the music as much. My hearing isn’t what it used to be but the top seems a little more muffled just after power up.
Like I said, perhaps 5 to 10 minutes seems to get back most of the involvement for me, so I suggest 10 to 30 minutes. But like burn-in every one probably has differing expectations/experiences.
-Ted
Again thanks Ted. Is there a way to keep the power on Ina reboot as in not shutting down ower at rear.
Mi wonder how much I feel is just not true and over time it blends or improves. But really it’s the trans. Honesty the honestly of this product to us is out standing.
No cannot think of one reproduction type device with such in house info to public.
Mad much as it is not allays what we want to hear it’s sure is great to read it from someone like you or Paul.
Inhabe another all tube dac with output transformers but they are much larger in size as setup to drive headphones directly. I wonder of its potential for chages.
Lastly does this occur for all transformer output devices. As warmup seems real enough to me you might have just given it new thought. I cannot wait to post this in other forums. If it’s iknwith you and is audio. Regarding our hearing I too question this. And at times it makes me feel to just the rough the trowel in. But when j hear so many things others don’t until I point it out. And then they do it makes me feel more content.
great reading as I sit I an emergency room with my 8 year old.
Al
I wouldn’t generalize experience with the DS’s output transformers to other devices.
The DS’s uses the output transformers differently than most other products out there (except some class D amps). Also the DS is different because the power supply interactions on power down and power up cause the digital and analog boards to temporarily not be generating DSD.
In hind sight I might have added a separate control to allow the display processor to disable and enable the analog power supplies, but we encourage everyone to use the front panel stand-by switch and leave the power on all of the time anyway.
There are many things in most products that are easy to get paranoid about but that don’t matter in normal use. Like medicine, too much information out of context often causes hypochondria.
Paronid is a great way to pose most audio people in general. But science can help with most as you point out. The others are just a little far for me. Regarding warmup Paul,pangs new PCI usb card has a Heater inside for the crystal . I have read from other that they leave there cpu on all,the time and a must for serious listening . I posed the question of rebooting I got no answer . ( really ) . Comes to thought.
But you are very difffrent in that you have taken the time to try many facets to improve things your self so repeatable by you matters to me as the same for me.
Thnaks
al
assisi said Can re-intialistion change the SQ?Yes, turning the DS off for even just a few seconds and turning it back on changes the sound quality more than you might expect. Before we realized that it made A/Bing of different versions of the code sort of hit and miss. If the FPGA freezes (which I haven’t seen except for power supply problems) then there will be DC current going thru the output transformer. Degaussing the transformers in that case will take some playing time. I suspect that when you turn off the DS since the digital power supply dies faster than the analog supply that there’s a short time where the FPGA is frozen but the analog is still working so you end up with a DC current thru the transformer for a short amount of time. Fortunately the DSD output for a zero (or muted input) is the best signal for degaussing the output transformers.
Thanks Ted for the answer. It is satisfying to know that it was not my imagination because sometimes the difference can be quite profound even though when what I would categorise as lower SQ, the DS is still very good. I just know how good it can be when everything is at their optimum including obviously the output transformers.
John
Ted Smith saidThanks Ted for the answer. It is satisfying to know that it was not my imagination because sometimes the difference can be quite profound even though when what I would categorise as lower SQ, the DS is still very good. I just know how good it can be when everything is at their optimum including obviously the output transformers.assisi said Can re-intialistion change the SQ?Yes, turning the DS off for even just a few seconds and turning it back on changes the sound quality more than you might expect. . . .
John
“I thought I did explain what changes 
Tho I expect that most people would describe the change in sound differently, for me it’s a slight loss of detail and pace. It just doesn’t make you want to move as much or draw you into the music as much. My hearing isn’t what it used to be but the top seems a little more muffled just after power up.” - Ted
So I’m not nuts, after all! Well, at least…
I’ve been doing lots of power downs/ups lately while testing some things and was getting depressed about the sound. I get up this morning and it sounds great. I thought that it was just the coffee and my mood or something. This is a really important observation for the Beta boys.