After a long search for a truly neutral, honest and transparent DAC for a reasonable price I've come across the Linnenberg Audio udc1 (listprice €1260).
(not to be confused with Lindemann which also has a DAC, though that one doesn't look very interesting to me)
I've just bought the udc1, it will hopefully arrive somwhere mid/end next week.
Couldn't find anything about the udc1 on this forum (not much on the rest of the Internet either) so I thought I'd start a thread about it with information and later a review.
If anybody else here has heard this DAC or knows more about it please share.
Not that looks matter much to me, I do really like the clean minimalistic pro look of the ucd1.
I've never liked "hi-fi" looking equipment personally, probably due to more of a studio background.
And minimalistic it is.
Only a powerchord and USB 2 input and 2 balanced XLR outputs.
Which is perfect for me, I don't need anything else.
Adding S/PDIF inputs only brings extra costs and often degraded performance when the USB is converted to S/PDIF first instead of directly to I2S.
The USB input is the asychronous USB M2Tech hiFace OEM board (up to 24bit 192kHz bitperfect with kernel streaming and wasapi drivers) which outputs I2S, making the DAC the master clock and giving very low jitter.
Since there are no S/SPIF inputs it seems to me there doesn't need to be any jitter cleanup etc, and there is no ASRC, giving a very pure digital signal path.
Design, construction and parts quality all seem very high and pure.
Some more info about the design:
The USB connector is galvanically isolated from the rest of the circuit by i-couplers and its own floating power supply.
The incoming sample rate is up sampled to a fixed rate of 192 kHz before entering the DAC chip. (I'm assuming this to be a synchronous upsampler)
DAC chip is the Burr Brown PCM1794a. (which we also find in for instance the April Music Eximus DP1, which also has async USB and a 192kHz upsampler btw, though also a much higher price and many additional features)
I/V / output stage is completely passive.
From the Linnenberg website:
"A passive I/V converter consisting of 0.1% precision resistors and the ultra low noise dual monolithic transistor SSM2212 is the perfect link between PCM1794A and the output buffers. This arrangement is absolutely free from slew rate induced distortions, provoked by high frequency out of band noise originating from the actual digital - analogue – conversion process."
"The subsequent gain and passive I/V stage is almost similar to the one used in the cdp3E. This discrete Class A signal path employs only the latest high quality parts from Zetex, Analog Devices and National Semiconductor. The output stage of the udc1 drives cables of any length as a result of the excellent wideband diamond buffer with 0.25A current capability. All voltage regulators are sourced exclusively from the leading specialist supplier (Linear Technology) with ultra low noise specifications (20uV).
No opamps. Zero feedback. Just music."
Now this output stage looks very attractive to me.
I don't know much about output stages and I/V conversion, but have been reading up on it a lot lately.
I've read that opamps can have trouble with the very strong high frequency noise comming of delta sigma DACs before filtering (which is actually stronger than the audio you do want). And that this could be partly to blame for harshness / treble glare / exaggerated dynamics/transients I know all to well from some other DACs.
I'm hoping this output stage will give true dynamics. Fast and exciting when the recording is, laid back and slow when the recording is.
Keeping my fingers crossed.
It looks to me that the designer, Ivo Linnenberg, has a very pure, skillfull, perfectionistic and rational approach.
I can really appreciate and identify with this.
I also spoke with him on the phone shortly for my order (very nice man btw), and amongst other things he told me he has affinity with the studio world.
That tells me more good things.
And it's just refreshing to see such a pure DAC.
The more I learned about how DACs are actually constructed the more I saw all the imperfections and nonsense.
Weird filter designs like minimal phase filters and apodizing filters, NOS DACs, ASRC and other "jitter reducing / removing" schemes that make no sense to me (an ASRC does not remove the jitter, it keeps the errors but simply gives it a different name), and many other marketing hypes.
None of this in the udc1.
The specs are modestly stated.
Frequency response: 1Hz - 24kHz +0.1dB -0.5dB
Distortion and noise: <0.01% 10Hz - 20kHz at -10dB
Output level: 4V rms balanced
Output impedance: 150 Ohms
Mains voltage: 115V, 230V factory set
Dimensions (H x W x D): 55 x 165 x 224 mm
At first glance the THD+noise of <0.01% looks a little on the high side.
But looking better you can see that it's specced at -10dB and for 10Hz to 20kHz and we need to remember that this is at 192kHz.
Most other DACs have their THD+N stated for a 1kHz sine at 0dB at 44.1kHz.
I've looked at the spec scheet for the PCM1794a, and it states that for 44.1kHz the THD+N is 0.0004% typical and 0.0008% max, all for full scale input.
At 192kHz the THD+N is 0.0015% typical, max is not stated but I logically assume it to be 0.003%.
As for most (all?) delta sigma DACs the THD+N is roughly a fixed value above / follows the theoretical THD+N of 24bit digital audio (it's roughly a straight line from the stated THD+N at 0dB to the 100% THD+N at the stated dynamic range, which point is between -127 and -132dB for the PCM1794a), we can calculate roughly the THD+N max at the -10dB stated in the specs for the Linnenberg udc1.
Doing the calculation finds roughly 0.01% THD+N max at -10dB at 192kHz for the PCM1974a. Exactly the same as in the specs for the udc1.
It's nice when things work out haha :)
So that tells us there's nothing to worry about here, and indicates the passive output of the udc1 also measures perfectly.
(edit: my calculations here are not correct. but the <0.01% THD+N stated spec is from actual measurement of the udc1)
I could not find any reviews of the udc1 on the Internet yet.
But there is a review by 6moons of the Linnenberg cdp3E CD player, which uses the same PCM1974a DAC chip and almost exactly the same passive I/V / output stage. I'm guessing it sounds very similar to the udc1.
6moons gave it a raving review on sound quality, saying it is better than the Weiss DAC2 and Burson HA160D.
Here are some extracts:
"cdp3E vs. Weiss DAC2: The Linnenberg fleshed out and texturized what the Weiss left drier, starker and paler. Quite matched on raw detail even though the cdp3E held a small advantage, the truly decisive factor was the legacy machine's greater image/tone density. Without any valves in the signal path, these qualities added up to what one usually expects from glowing bits whilst avoiding their liabilities. Transparency itself is ghostly. In more ways than one you see right through it. To mistake a virtual for a real performer without the aid of sight needs something extra, even compensatory. Think of it as incarnation factor. It turns ghosts into believable presences. For that our hifi must grab us on a nearly instinctual gut level far away from the mind. There dynamics certainly factor highly but during playback in the home they hardly ever approach realistic breadth and the true violence of live peaks. What's left then? However you define it, that's what made up the core difference between Linnenberg and Weiss."
"cdp3E vs. Burson HA160D: This juxtaposition inverted the above. Very well matched on that—flesh & blood, incarnation factor, your term—the German had the superior ambient retrieval. This micro detail wrapped itself around performers to extricate them to a higher degree from the soundfield to become nearly freestanding entities. While this freestanding illusion never comes off fully, the cdp3E went just a bit farther than the HA160D. The sense of presences interacting with defined recorded space was more acute. In declining sequence of excellence, it thus was Linnenberg, Burson, Weiss. The first two shifted an important dividing line. Lesser albums apparently flat dimensionally and tonally would still sound flatter than their more masterful peers but no longer flat per se. The more incarnation is in place, the broader the scope of CDs or music files becomes that can sound very satisfactory. This is key to enjoying a library that's built from the music up rather than the sound down. The cdp3E brilliantly checked off all the usual audiophile attributes centered around resolution. More importantly, it began steadfastly on the other foot of physicality and substance."
"Since my embrace of computer audio in early 2010, the Linnenberg became the first legacy player I've met—or let into the house—which suggests that the rationale or justification for its kind hasn't entirely expired yet. For the cdp3E it has most certainly run out on features (cough) but not on performance. To hard-boiled hifi fanatics that could be sufficient. Softening the scratchy hair shirt is the very attractive €4.500 sticker for a better than €3.000 Weiss converter + CD/Pro transport with custom servo board and all European manufacture."
Well that wraps up the info I could find and my thoughts on the udc1.
As you can read, I'm already raving about this DAC before I even heard it :)
It's because I feel well enough educated this time to make an assumption on what makes a good DAC, and had been fantasizing about how my ideal DAC would be constructed. I was even considering building my own DAC.
Didn't really want to go down that road as it would take a lot of time in research and the potential for error due to inexperience would be high.
But then I found this DAC, almost exactly how I fantasized my ideal (but reasonable cost) DAC to be like.
Asynchronous USB to I2S to PCM1794a, clocked from a low jitter clock, to passive I/V. All with a high quality power supply and parts. Only I would have personally done upsampling on the computer (will still do this) but the built in upsampler of the udc1 is kind of like a bonus that will come in usefull at times.
I'm sure that had I tried building it myself (based on a collection of DIY designs available online) it would have been nowhere near as well done as this.
But the proof is in the pudding :)
I'll let you all know how it actually sounds when I get it.
I hope I will not have to give another dissapointing review like with the Lavry DA10 and Yulong D18.
But I strongly suspect that won't be the case this time.
Btw. I thought it might interest some of you here that there is also a fresh new headphone amp available from Linnenberg Audio, the spa1 (listprice €970).
Perhaps a good partner for the udc1?
Not interested in this myself as I've switched to speakers only for the moment (Klein+Hummel O300 and a very big high ceiling great sounding room. Thought I'd better put all my money in one great speaker setup than spread it around and have a less great speaker + less great headphones setup)
Disclaimer: I'm not affiliated with Linnenberg Audio (or any other audio company for that matter) in any way.
I'm thinking about why I'm writing this info and soon to be review down.
I guess I've started to feel involved with this online community after spending countless of hours reading reviews and discussion here, first about headphones and lately about DACs. Perhaps sharing the results of my DAC search can help some with their search.
Combined with excitement about my comming new DAC and there you have it :)
Edited by slackman - 1/10/12 at 10:21am