Ladder Schumann R2R DAC Review

[srkbear]

The power supply in any digital device has the critical job of dealing with square waves switching into loads. The loads being the next IC downstream. As each load in the circuitry draws power they can affect the power supply loading in ways that are detrimental to the entire unit. Inductors are used on the power supply rails and are placed as close as possible to the loads/ICs power input(s). The inductors reduce the amount of square wave feedback that would usually reach all the way back from the ICs to the power supply where they would affect the other ICs due to the power supply having square waves riding on the output. A R2R design is digital on steroids and whether they are conserving space by using a toroidal transformer or designing for shock and awe I don't know but the power requirements of the R2R are so much more demanding for what is already a demanding task.

Thanks for clarifying about R2R DACs, which makes sense but is unfortunately the sole conclusion I could glean from your text—I tried my best to get through it, but it was obviously an example of the sort of insider jargon commonly spoken amongst high level audio scientists. I’ve been around here for quite awhile, and I hope I’ve been sufficiently transparent that I’m not an electrical engineer, just a lifelong enthusiast with an excess of curiosity about what’s going on under the hood. I am for sure always eager to learn.

But through no fault of yours, your explanation soared way over my head—it kinda brought to mind what would happen if I read my progress notes to one of my patients in an effort to educate them about their diagnoses and prognoses. My shop talk would offer them minimal insight, but could easily terrify them.

Perhaps the intimidating tone was due to some perception that I was being snarky to you in my original question, which was absolutely not my intent—and if I came across that way I apologize. I hope you’ll make note that I did start by asking if this power supply requirement was specific to R2R DACs, as it didn’t make sense to me for DS DACs. And thankfully you eventually got around to confirming that in your final sentence, so all is well!

I’ll never have the fund of knowledge to comprehend the rest of what you wrote, but that’s ok. The most important lesson I learned from the exchange is that there’s just one more byzantine, technological complication with R2R ladder DACs that renders them all the more tragically inelegant and obsolete, and baffles me even further that some folks still treat you like hopeless rubes for not shelling out ten grand to own one. What could they possibly be thinking, really? Anyways, peace and happy holidays! —Steve

 

[Doodski]

Thanks for clarifying about R2R DACs, which makes sense but is unfortunately the sole conclusion I could glean from your text—I tried my best to get through it, but it was obviously an example of the sort of insider jargon commonly spoken amongst high level audio scientists. I’ve been around here for quite awhile, and I hope I’ve been sufficiently transparent that I’m not an electrical engineer, just a lifelong enthusiast with an excess of curiosity about what’s going on under the hood. I am for sure always eager to learn.

But through no fault of yours, your explanation soared way over my head—it kinda brought to mind what would happen if I read my progress notes to one of my patients in an effort to educate them about their diagnoses and prognoses. My shop talk would offer them minimal insight, but could easily terrify them.

Perhaps the intimidating tone was due to some perception that I was being snarky to you in my original question, which was absolutely not my intent—and if I came across that way I apologize. I hope you’ll make note that I did start by asking if this power supply requirement was specific to R2R DACs, as it didn’t make sense to me for DS DACs. And thankfully you eventually got around to confirming that in your final sentence, so all is well!

I’ll never have the fund of knowledge to comprehend the rest of what you wrote, but that’s ok. The most important lesson I learned from the exchange is that there’s just one more byzantine, technological complication with R2R ladder DACs that renders them all the more tragically inelegant and obsolete, and baffles me even further that some folks still treat you like hopeless rubes for not shelling out ten grand to own one. What could they possibly be thinking, really? Anyways, peace and happy holidays! —Steve

I was trying to simplify as much as possible although it's difficult to do that when we have new buzzwords and concepts involved. The easiest method to explain I suppose is to revert to the water analogy. The R2R DAC power supply is the main water reservoir supplying all the ICs and circuitry with water. As digital circuitry uses square waves there are issues that results each time a square wave draws water from the reservoir. So imagine many times per second that the square waveforms in the digital circuitry are switching ON and OFF and each square wave when switching ON and OFF can send water pressure feedback all the way back into the main water reservoir. That water pressure change in the main reservoir would affect the other square waves in the device and so this feedback must be eliminated or minimalized as much as possible. To do this a coil of wire (inductor) is placed inline on the water flow and that prevents feedback from the digital circuitry from going back into the main water reservoir and polluting the water reservoir with energy that we don't want in the power supply water reservoir. Kind of like pinching off a garden hose and then the water pressure wave goes back inside the hose all the way to the main water system and it will affect the water pressure at the bathroom and kitchen etc. So the water pressure will pulse with each pinch of the garden hose. Imagine thousands of pulses/pinches per second and things can get messy and stuff happens that is unwanted. So to stop this water pressure pulse from traveling back up the hose to the kitchen and bathroom we could install a pressure regulator inline to dampen or eliminate the water pressure pulse.

The R2R DACs are power gobbling monsters that have many issues and one of them is the power supply needing to be able to supply a steady uninterrupted flow of electricity/water to the ICs and other circuitry. Hence the maker of the Ladder Schumann R2R DAC made a pretty heavy duty power supply for their DAC. Whether that toroidal transformer is required I don't know but they are usually smaller in size than a regular iron core transformer. That saves space. That and toroidal transformers look ace-cool and this model is all about the cool factor for some people.

Happy holidays.

 

[zajogungster]

Interesting that they even machined a branded lid for the transformer!

Thanks for the review!
i know people what they like is that it is packed with parts, in a nice sleek layout and more than the sound they enjoy and love the interior and the cosmetic features.
nice machine