R-2R Ladder DACs (in production 2015)

Any others in production today? Views on these specifically or on R-2R versus Delta Sigma in general?

Aqua HiFi La Scala
PCM1704-K (4) Dual mono

CH Precision C1
PCM1704 (8) Dual mono

Computer Audio Design CAD 1543
DAC Philips TDA1543/N2 (16)

Metrum Acoustics Pavane
Propietary "Transient" chips

MSB DAC V
Discrete (proprietary)

Schiit Yggdrasil
AD5791 BRUZ (4)

totaldac d1-twelve
6 discrete ladders per channel (600 vishay foil resistors)

Trinity Electronic Design Trinity DAC
PCM1704

There's a lot more to these DACs, and any DAC for that matter, than the D/A conversion. I did hope to focus on that aspect primarily in this thread though.

 

Thanks so much for posting this list.

It would be very useful to have prices next to these. I suspect that at least some of these units are well into the 5 figures price-wise. Speaking strictly for myself, I would never even look at a 5 figure DAC. Never.

I suspect others may share my sentiment.

 

Yeah, I wanted to leave price out of it so the focus could be on R-2R. Maybe after we get into it a bit. For now, let's just agree that pricing is way out of control for any number of them.

Hope your Yggy is working out. I doubt there's an R-2R which delivers more value.

We should have some members who can elaborate on today's R-2R in general. Once we make some progress on D/A, then it would be a good idea to get into power supply, analog, etc. I'm planning to make a solid effort to inform myself on the modern digital front end- the DACs and the "digital transports". The bottom line will always be listening, but it won't hurt to have a pretty decent understanding of the design principles. For now, I'm of the view that implementation is what matters most and not necessarily one design principle or another.

 

I'm auditioning an Aqua La Voce S2 R2R/Ladder DAC right now actually. I'm comparing it to my Schiit Gungnir delta sigma DAC. I'm also demoing a new 2 channel amp at this point so the overall change in sound is tough to nail down to the DAC specifically. I still have to take a look at the box for the unit to see if I received the dual Burr Brown unit or another - La Voce is modular whereas La Scala is not.

Edit - confirmed I do have the dual Burr Brown model

 

Lavry DA2002

 

I'd love to look at and hear the Totaldac on headphones with a variety of amps and a variety of headphones. Just so I know what it sounds like. And so I can find out if headphones are able to let me hear what a DAC like that does. Some say that DAC goes 3D. And I'm chasing 3D style sound on headphones. So it would be neat to know what it does, and if it does what is said it does. I put it in the category of curious to hear but totally cannot afford.

The Yggy is about as far up the ladder as I can justify for a DAC. Especially with just a headphone rig. I've been seriously considering the Yggy.

 

I think you can get a multi bit DAC just as wrong as a delta sigma.
I owned a couple of Audio Gd DACs that used multiple 1704s that were OK but nothing special-pretty lifeless sounding.
I have heard some reasonable TDA 1543 based DACs and they can be quite cheap.
Accuphase and Vitus manage to get their delta sigma DACs sounding very human and very good.They are great amplifier makers though so really know their way around power supplies and discrete output stages.
Krell and Accuphase made some sublime sounding CD players and DACs using PCM 1702s.A much underrated chip and I believe every bit as good as the 1704 and TDA 1541.

Primare use 1704s in their DACs.

But yes I find multi bit ladder DACs have some real musical soul and conviction.
The Accuphase DC61-now THAT is the real deal-with its twelve 1702s.

 

For someone who has a generally good understanding of digital audio, but not what this thread pertains to - anyone care to give me a primer on the what why and how? Don't be afraid to get technical, lay it on me.

 

The totaldac d1 line features chip-less conversion of PCM to analog. Beyond that, there are some key variations moving up from the entry level d1 units to the flagship such as elimination of active discrete Class A output stage. Also, there is a filter intended to compensate for NOS deficiencies which can be defeated. Attenuation is handled by FPGA with custom 69-bit DSP.

Note that DSD must be converted to 24/176 PCM.

The d1-twelve would certainly be a "must demo" for anyone interested in hearing the most important DACs on the market today.

 

I can't get technical for you, so we'll let some others handle that. For the non-technical, we are discussing non-oversampling (NOS) DACs. These R-2R ladder designs take a different approach to conversion to analog from the typical oversampling Delta Sigma DACs.

As far as I understand it, the primary advantage of R-2R is the absence of pre/post ringing. The main disadvantage is a shortcoming of some sort in the treble. There is, of course, far more to any DAC than conversion itself. Hopefully, we can touch on these various concerns in an effort to generate interest in today's digital front ends. So much is happening. Exciting times!

Maybe someone could list the broad 4 or 5 DAC types today? Among them will be DSD for everything FPGA (DirectStream, Playback Designs), NOS R-2R, Delta Sigma (Berkeley), etc.

 

Discontinued.

 

Their flagship DAC 30 uses a Crystal CS4398, which is not R-2R. I think? Perhaps there is another production model which uses the 1704. I tend to doubt it since supply of that chip is short.

 

Thanks for that, really appreciated. A NOS DAC sounds like something I would be into. I'm looking forward to even more technical discussion here

 

Must have been recently, then.

I don't think R-2R and other multibit topologies are inherently superior or inferior to sigma-delta DACs. I am a firm believer that the DAC chip itself is probably the LEAST important component in terms of sound in a digital audio component, with the post-conversion analog circuitry having the most significant impact on the sound. If modern DAC chips are properly implemented and performing to spec, their noise characteristics, SNR, dynamic range, and effective resolution should render any differences in sound of the chips themselves beyond the pale of audibility. The one area where there might be slight differences, primarily in HF reproduction, are in the different digital filter designs, IMHO.

 

Although I also can't get too much more technical, it's far more complicated than that. delta-sigma uses D>A conversion more like DSD, and PCM signals must be transcoded before conversion. More, it is filters before the actual DAC which typically do the oversampling and a ladder-type DAC can also have oversampling filters in its input.

 

To me, it's like the vintage Les Paul (seller wanted $15,000) that I had an opportunity to play. I passed. That guitar would have ruined me for the axes I have at home (a 1999 Les Paul Classic among them). What's the point of knowing what a DAC I can't afford sounds like? But I'm not trying to discourage you from your "3D quest". The forum seems to always benefit from your audiophile experimentation.

Regarding the Yggy, I couldn't be happier. I'm a huge advocate of PCM->DSD upsampling to improve the sound of Redbook. But with the Yggy, unadulterated 16/44.1 sounds just stellar. So much so that I've lost a bit of interest in hi-rez PCM. Seriously.

 

I don't know if the chip is least important, but I'd agree that the way that the chip is being used is more important than the chip make/model. Additionally, there a few DACs in the R-2R list which have no conversion chips at all.

I'm in the camp, as of now, that the best end-to-end implementation is more critical than Delta Sigma versus R-2R. The over-sampling DSP filters (mostly for Delta Sigma) are where quite a bit of proprietary design effort is spent. There are those designers, however, who are committed to NOS and I think we'd find that these engineers believe that if oversampling were implemented that it should be done by a computer and not within a DAC. These are the types of viewpoints to keep in mind in order to gain a basic understanding of DAC offerings out there today. There are hardliners against op-amps in the analog stage, for example. And then there will be a few guys who use an op-amp in a unique way. And on and on.

 

Good to hear!

One aspect I might go for is the modular design, which is conducive to hardware upgrades as developments come about. This wouldn't be as important to me with the Yggy, since the price point is so attractive. If you ever want to sell it in the next few years, then I've got to believe you will do very well. For me, well, I plan to transition to the "digital transport" once pricing and advances work themselves out. By then, I'd like to feel good about my understanding of DACs.

On that note, the DACs listed are primarily geared to USB input. This aspect is also a fluid situation as shortcomings are being identified and overcome.

 

My demo unit is new (as far as I know) so I'm probably judging too harshly too early, but during the entire three hours I was listening last night - I really liked the sound, it is very highly resolving and sounds very smooth and listenable. However, the La Voce seems to have taken some of the sharp edges away from music, things almost seem rounded off a bit. I didn't get any sense of drama or emotion out of anything I listened to, to be completely honest. I'm comparing it to a sigma delta unit from Schiit. It needs to burn in for a few more days (it's playing constantly right now in my room) before I think it's fair to judge but it's got a pretty uphill climb to justify the asking price based on initial impressions.

 

Audio Note has a discrete (tantalum) resistor DAC in development, but the ecrutiatingly close matching required presents a formidable production hurdle.

The initial prototype, heard over a year ago in Munich, sounded amazing.

 

Do you have the D104K unit? Using USB out from a computer?

Another option is Metrum Acoustics Hex, which is one model down from the Pavane noted in the first post.

 

I do have the D104k, USB out from PC through a Regen into the USB in on the DAC. I don't have equipment to utilize any of the other inputs but USB does sound at least as good as Gungnir. Due to a bit of a logistical failure on my part, I'm having to use a long, "throw in" USB cable instead of my Supra cable but honestly I'm not noticing anything "off" about using the cheap cable (I know, can of worms, different discussion)

 

Audio-GD master 7 uses PCM1704. The sound signature is warm.

Schiit will be announcing multibit/R2R upgrades for their mid-tier DACs (Gungir/Bifrost) in mid August. (note: not 100% confirmed yet but the cat is basically 2/3rds out of the bag)

 

Interesting. Thanks! China. They also have a line of ESS9018 DACs.

Is the 1704U-K different than the 1704K. I know there were a few variations of the 1704, but I don't know what they are.

 

So NOS = R2R = Ladder DAC?