Søren, the designer of the dac1541, and CEO of Soekris Engineering, very kindly sent us (SBAF) a loaner/tour unit of the dac1541 to evaluate, measure and get some feedback on. This will be included in the “Life after Yggdrasil” thread for the usual comparison/evaluation, but ahead of that I wanted to post some thoughts in a “stream of consciousness” style. Why the difference here? Timing mostly; through the end of this month the dac1541 is available for €1110 instead of the usual €1290. My full write-up/comparison is not going to be done by that deadline, so this might help those interested come to a decision in time to take advantage of that offer. About the “dac1541”: This is a discrete R-2R sign/magnitude balanced DAC and headphone amplifier. It offers USB, AES, BNC/RCA Coax and TOSLINK inputs. The electrical inputs are transformer coupled, so already offer some electrical isolation. There are balanced (4-pin XLR) and single ended (1/4” TRS) headphone outputs, and balanced (dual 3-pin XLR) and single ended (RCA) “line” level outputs. It offers four different cross-feed settings and four different filter options. It’s possible to set the power-on output level for the headphone and “line” outputs independently, as well as which mode the unit fires up in. Since this is both a DAC and a headphone amp this is filed in the “Amp, DAC/amp” section. Notes on these “Impressions”: They will initially be focused on listening to the unit as a complete solution - i.e. driving headphones directly. More details on the raw-DAC operation will follow, along with formal comparisons and the results of much more vigorous listening sessions, in the “Life after Yggdrasil” write-up. Bear in mind that, as this is a “stream of consciousness” approach, impressions may change as listening progresses. Most notably, there are some things that do not become apparent in short listening sessions nor, necessarily in A/B comparisons … for example fatigue and overall musical enjoyment/engagement are best evaluated over protracted listening. And things that can be initially welcome or impressive can turn out to be grating or superficial. The unit has been powered up, playing music, for at least 72 hours straight and the details on the sound are based on listening from that point on. And, since I’m doing this quickly, I encourage @soekris to chime in to correct any factual misstatements. My desire to get some thoughts posted is limiting my normal “dig into the guts of the thing” time and will have to wait for my full-write-up. Digital Volume Control: Volume control is in the digital domain, and is in the chain for both headphone and “line” outputs. This actual volume dial appears to be a stepped encoder and rotates continually (no min/max limiter), with tactile “detents”. If you turn it slowly you get changes in 1 dB steps, turning it faster and those steps become bigger. If you push things too far, then the “clipping” light will start to flicker and eventually just be “on”. Keep your playback levels such that this light never illuminates. Which is easy … don’t go over 0 dB on the display and you should be fine – at least for “line-level” usage. My understanding is that with the level set to 0 dB, there volume control does not change anything about the signal (typical for digital volume control) and is effectively not-present. This is typically how you’ll want to run the unit in “line” out mode. Headphone Output: The only source for the headphone “amp” is the DAC itself. Unless I’m wrong about the implementation of the line-out and headphone connections, which is entirely possible, this means that there’s not a practical way to evaluate just the performance of the headphone “amp” part of the unit. So, in essence, this means commentary here, which is where we are going to start, is always about the unit as a whole. As always, I’ve used my Abyss, LCD-4, Utopia and HD800S for my listening. I threw in the LCD-2 and HD650 for good measure. I’ll try it with IEMs as I have time - mostly to check for “hiss”. The dac1541 has no problem at all driving the Utopia or HD800S, LCD-2 and HD650; speed and control are maintained easily up to the highest volume levels I am willing to listen at. With the LCD-4, while it drives pretty well, they’re not quite delivering what I routinely experience them as being capable of. The same is true with the Abyss. This isn’t necessarily affecting the quality of the reproduction per-se, though both the LCD-4 and Abyss have a more “visceral” sense to them when driven via the line-out and through my primary headphone amplifiers. The headphone output is generously powered (3.4W @ 50 ohms), so this is a bit of a surprise. I have gotten up around 0 dB on the volume control with the LCD-4 with some tracks, however, and at that point the clipping light will occasionally flicker. Sound: TL;DR; I like it. It’s more on the reference*/analytical side than the euphonic/musical side in terms of presentation, exhibits very good detail, is tonally neutral, and has excellent separation. This seems to be a sonically competent entry into the discrete R-2R DAC market. The combination of DAC/amp seems easily appropriate for its price-point (probably a bit above that level in fact) and for the types of transducers it is most likely to find itself paired with. And in more detail: The bulk of the comments in this post are based on listening via the balanced (4-pin XLR) headphone output on the unit. Some results from running it via my WA5-LE or Pro iCAN, but that has mostly been to see if what I’m hearing is a function of the DAC itself or has to do with the power available from the headphone output. Obviously, the full write-up will make it clear which is which and will focus on the DAC side of the equation with external amplification, as will follow-on commentary. … SOotB: Coming straight out of the box, hooking it up via USB, and just listening briefly to make sure things were working …. the sound I get here is very clean, clear and highly detailed/resolving. “Pristine” is the word that came to mind when first considering how the unit sounds. I would, with one interesting (to me) caveat, describe the general tonal presentation as neutral and reference-like*. What’s that caveat? When listening more casually I’m slightly more aware of the lower and upper registers than I am normally. That would suggest a very slightly U-shaped character. That’s probably a mental artifact rather than an actual effect – but it’s something I’ll have to revisit in the more detailed listening sessions. The sense of detail offered initially is very reminiscent of the better ESS/Sabre implementations, albeit without the “exaggerated” or “fake” nature of the Sabre stuff. That’s a good thing. I did not listen a great deal at this point … and instead left the unit to “warm-up”. After 72 hours (and change): Soren has said the unit didn’t need any burn-in … but I still like to let R-2R designs come to thermal equilibrium before getting into formal evaluation – if nothing else but for the sake of consistency. The resolution/detail and clarity is still the first thing that strikes me upon beginning to listen again. This doesn’t change between using the USB input (directly) and the AES input (via Aries). Again, for consistency, I switched to using the Aries via AES as the source for the bulk of my listening. While I’m told there shouldn’t be a difference between USB and the various S/PDIF interfaces, I get the sense of a slightly “harder” aspect to the music via USB than I do with AES and S/PDIF inputs. That is NOT to say that this unit actually sounds “hard” via USB, just that I felt it was “harder”. I would take this with a grain of salt, as it's early days and I'm by no means certain which way is preferable or if that sense will persist. Tonality is natural and realistic. Music has a natural sense of pace without any of the apparent “fast” or “slow” effects that are sometimes perceived. Separation and layering are excellent. This is probably the most obviously noticeable trait of the unit beyond the level of detail on offer. There is a deftness to the way notes are handled that is quite enjoyable, with light, rapid, plucks on strings or hits on percussion being conveyed in a very agile and, where appropriate, delicate manner. Notes start seemingly instantly and decay is natural and easy to follow to its conclusion. The filters are, with a little focus, audibly variant and after a little time you should be able to tell which you’re listening to. I’m finding myself on the default (filter light is orange) filter about half of the time so far (which is some mix between linear and minimum phase), and with the filter light extinguished indicating a “soft minimum phase” filter. That’s not to say these will wind up as my preferences, or the best the unit sounds … much listening to do there. The cross-feed function is meaningfully more obvious in its instant effects than the filter settings. Too early to say if I like it, find it reduces fatigue, or if it improves spacial presentation (left to right). You can definitely tell the difference with each of the settings, however and it’s not mucking up the overall sound, which is a good place to begin. .. LOTS more listening to do, and lots of specifics to get into … most of which will probably have to wait until next week now. -- *Many seem to take the phrase “reference” as some super-high-praise “this is the shit” affirmation. For me it just means that I’m not hearing specific coloration. Yggdrasil has a “reference” presentation for example, where as “Gungnir MB” I find a little warmer and as a result I would not use the “reference” descriptor there. Compare that to, say, a Linn Akurate DSM … which also has a “reference” like tone but, for me, is easily beaten, overall, by the Gungnir MB. Thus, for me, this term speaks to signature, not quality/performance levels.