Rev2+470uf I think.
Also, it is confusing that you didn’t see any notable change in measurement before and after the mod, even though we all heard great improvements (or at the very least differences). You also recorded the outputs and did AB tests so I suppose the result is reliable. So, does this mean that measurement doesn’t tell the full story even with an R2R system?
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Of course not.
Today I compared a Sigma Delta converter widely used in pro audio circles (Lynx Aurora16), an old Troisi Design R2R DAC and the DAM1021 again.
No contest. The DAM1021 with the soft filter sounds full, detailed and natural. The others have a little more sparkle, but sound smaller and slower, less dynamic, and the SD converter has the typical haze in the high end.
Measurements? In terms of THD+N the DAM1021 is worst, but we know harmonic distortions aren't audible above a certain threshold. It's ironic that everyone looks for that measurement first in audio gear...
Nice. Is the Troisi Design DAC also discrete ladder or chip based? There are other measurements than THD but I don’t know if any of them can explain an enhanced bass from the vref mod. The point I was getting at is that if the measurements can’t ensure quality even in a well-implemented R2R system, we wouldnt be able to claim that an R2R system is nearly perfect just based on the measurements. That would be quite disappointing for those who want less uncertainty.
The Troisi DAC is based on laser trimmed monolytic ladder ICs.
I've dealt with effects so often in analog designs that appear to be dynamic (audibly) and don't show up with 1khz or 10khz sinewaves.
THD is good to establish baseline and fine obvious problems, but it doesn't tell you about many interesting parts of the story.
Which is four boards and at least $600 more than dual-mono... The output impedance doesn't matter if you have a preamp with 50kR input impedance which is not uncommon at all. Also NC400 power amp is speced for sources up to 1kR, not so far off from 1.3kR out of the dam1121 ladders. So it is not inconceivable that you can even directly connect the bridged outputs to a power amp.
Interesting that it wasn't as good as dam1021, perhaps it's an industrial chip thus not sign-magnitude?
I trust that you're right that measurements cannot explain audible differences not caused by the audiophilic imagination. But if we can't come up with more revealing tests, for one thing, it means that the only way forward is through careful "technical gold-digging" (as coined by TNT). This process requires the direct comparison of a modded unit and an unmodded unit in a controlled environment which is not so easy for ordinary users. For another, it raises the question of what might possibly be improved in the dam1021? Has anyone (besides Soren) done ABX testing on 0.05% vs 0.01%?
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It's an old DAC with a far less sophisticated clock and filter. Obviously not sign-magnitude, but that shouldn't matter for signals at a sufficient amplitude.
Measurements can and should explain the differences. It's the reliance on THD that I find problematic. Science has shown that below a certain threshold it is basically inaudible. Yet it is widely seen as the most important measurement.
Most consoles, and especially most mixing / mastering chains have worse THD+N than the DACs availible today. Tape recorders are still worse. I love the sound of tape. But not because of static harmonic distortion, but because of pretty hard to fully grasp dynamic effects going on in the medium.
And you can add harmonic distortion at will in the digital domain. It won't create what we like about certain analog gear.
As for testing a modded vs an unmodded unit - I will have the opportunity soon when I start building my 32 channel studio DAC in earnest. I'll record modded and unmodded examples through a state-of-the-art AD converter and upload them here.
I am sufficiently convinced that the Vref caps are necessary in rev.4/5 to get good bass and a number of other improvements, but recorded test tracks from modded and unmodded boards would be very much appreciated for ABX and a more scientific perspective!
I also read that the last bit of THD doesn't matter, and I think Soren believes that anything below 0.1% is inaudible. But since the Vref improvements seem unmeasurable (THD, IMD, dynamic range, SNR, square wave, etc.), could there still be a large gap between dam1021 and the perfect dac? Assuming that THD doesn't matter to our ears below 0.01% and that resistor accuracy only affects THD, we should be able to claim that dam1021 will at least sound the same as a dac made with perfect resistors. If the previous point is admitted, what else is there to improve on theoretically? The new 4k linear filter sounds no different from the 1M tap linear filter in HQPlayer which is pretty much theoretically perfect (though I don't reject the possibility that someone with more revealing equipment and better ears might pass an ABX test with it). The ps scale jitter probably is inaudible, I don't believe the output cap worsens the sound audibly, is there any other potential problem in the super simple and transparent R2R system? How can MSB or TotalDAC possibly do better?
Maybe it's time for Soren to start an aggressive advertising campaign against TotalDAC and MSB, and have those guys send us proof that their products are better...
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I have to admit I'm still a bit obsessed and not in the right frame of mind at the moment, but here's MSB DAC IV measurements again: MSB Technology Platinum Data CD IV transport & Diamond DAC IV & D/A converter Measurements | Stereophile.com
0.005% harmonic distortion. I honestly can't understand why people bother with MSB Technology. The giant CNC aluminum chassis does little to shield the radiated EMI from the toroidal and adds only weight. You'd have to be the vainest audiophile in the world to consider it at $43,325
The slightly newer analog dac seems to measure better, but still: MSB Technology Analog DAC D/A converter and Analog Power Base power supply Measurements | Stereophile.com
ffs you can almost get a dac1541 with the price of MSB's volume control add-on
0.005% harmonic distortion. I honestly can't understand why people bother with MSB Technology. The giant CNC aluminum chassis does little to shield the radiated EMI from the toroidal and adds only weight. You'd have to be the vainest audiophile in the world to consider it at $43,325
The slightly newer analog dac seems to measure better, but still: MSB Technology Analog DAC D/A converter and Analog Power Base power supply Measurements | Stereophile.com
ffs you can almost get a dac1541 with the price of MSB's volume control add-on
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Jan, the main reason I offered advice earlier was that I have been reflecting on my decision sometime after I started my build last year to go dual-mono. It seemed perfect at the time - I have just enough space for an extra board, plenty of clean power, reliable inputs and controls that don't need much tweaking to get a second board running. My back panel would also look much more pleasing with the 4 channel raw outputs of dual-mono. It's not like I desperately need the cash for anything, and I already spent quite a lot of time getting one board running, so why not add a second for just a bit more money? I certainly didn't consider the fact that lower THD at this level is most likely inaudible, and the only real benefit is probably 3db of dynamic range, if even that. All this is after I manage to overlook the few uS of possible delay between the two channels.
What bothers me is not the extra cost involved, but the decision I made. I don't believe that forgetting is a good way to deal with one's past, if only because of what we can learn from it. It is clear from simple thought experiments that perfectionistic motivations played a part in my decision, as well as insufficient understanding of the benefits of dual-mono.
But given what I know now, would I make the same decisions as I did? Jan, despite all this, I think you are in a better position than I since with the dam1121 you can choose to go 4 boards if you wish and maintain perfect synchronization, which would take you to the 8 channel configuration of TOTL MSB dac, and a bit short of TotalDAC's 12 channel configuration (though they somehow seem to have half the resistors we do, i.e. 50 compared to 100+ per ladder, 2 ladders per board). Statistically, given a large enough number of boards paralleled, the distribution would converge almost surely to the expected value. But one caveat is that I'm not sure if the expected analog output given resistors with tolerance would have 0.0% THD, even though the expected value of the resistors is probably 0.0% from the spec resistance.
I don't think all this information would automatically give a decision, however. The complex circumstances of each person differ greatly. But for me, justifying a dual-mono configuration is not that much easier than justifying the build itself, even if I knew back then everything I do now. The element of risk and uncertainty is almost inevitable in both decisions. I find it hard to tell how much an equipment will be worth to me personally, unsurprisingly perhaps, most of all something that purports to reproduce art. Of all the things we care about, some we can't hope for and may never know, others we hope for and find out eventually, yet others we hope for but may never know for sure. Perhaps this would fall in the final category.
What bothers me is not the extra cost involved, but the decision I made. I don't believe that forgetting is a good way to deal with one's past, if only because of what we can learn from it. It is clear from simple thought experiments that perfectionistic motivations played a part in my decision, as well as insufficient understanding of the benefits of dual-mono.
But given what I know now, would I make the same decisions as I did? Jan, despite all this, I think you are in a better position than I since with the dam1121 you can choose to go 4 boards if you wish and maintain perfect synchronization, which would take you to the 8 channel configuration of TOTL MSB dac, and a bit short of TotalDAC's 12 channel configuration (though they somehow seem to have half the resistors we do, i.e. 50 compared to 100+ per ladder, 2 ladders per board). Statistically, given a large enough number of boards paralleled, the distribution would converge almost surely to the expected value. But one caveat is that I'm not sure if the expected analog output given resistors with tolerance would have 0.0% THD, even though the expected value of the resistors is probably 0.0% from the spec resistance.
I don't think all this information would automatically give a decision, however. The complex circumstances of each person differ greatly. But for me, justifying a dual-mono configuration is not that much easier than justifying the build itself, even if I knew back then everything I do now. The element of risk and uncertainty is almost inevitable in both decisions. I find it hard to tell how much an equipment will be worth to me personally, unsurprisingly perhaps, most of all something that purports to reproduce art. Of all the things we care about, some we can't hope for and may never know, others we hope for and find out eventually, yet others we hope for but may never know for sure. Perhaps this would fall in the final category.
This is an extraordinary statement. I know what goes into the development and engineering of the MSB product and it is very very sophisticated. I suggest that you get an opportunity to talk to them at one of the audio shows, and take some music along for a listen.
Sophistication does not imply effectiveness. There is nothing inherently wrong with buying MSB, but I don't think I'll be doing it. The only question I want them to answer is: why is MSB better than a dam1021? And I'm not sure if they have a good answer. What they have on their website is certain unconvincing.
I've done several A-B tests between my DAM (in various stages of development) and a Rockna Wavedream (the first one, with MSB's R2R modules) at a friend's house. The rest of the system was equally impressive (ASR amps, ATC 100 speakers, etc).
In all cases, it was no contest. In the end, the DAM put on a good show, but the Rockna was definitely better in all aspects.
I'm not saying that it was a fair comparison, since the Rockna is a balanced design costing more than 10 times as much as my DAM build, but it is what it is.
In all cases, it was no contest. In the end, the DAM put on a good show, but the Rockna was definitely better in all aspects.
I'm not saying that it was a fair comparison, since the Rockna is a balanced design costing more than 10 times as much as my DAM build, but it is what it is.
Did you try the SE output of Rockna? Also even if the sound is different I’m not convinced that it’s better... this is not to say that others can’t arrive at a different conclusion
Btw, you should do the vref mod quickly, update to 4k filters, and do another comparison. The new 4k filter sounds quite different from Paul’s.
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Where are these on the board? Picture. Cxx?
I have been struck by a sudden urge to modify. Da*n you ynmichael ;-)
Thanks!
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