Vintage/Current R2R DAC Owners Discussion, Insight, and Review Thread

[astrostar59]

  You're thinking of the DIY board. The dac1101 is an actual product with the dac on a custom board that is in an enclosure and has a USB input. 

You are correct, sorry, that is a new product. I have read it will be better with a more advanced line stage (no opp amp). But for the money looks hard to beat.
 
But TBH I would look higher up the scale for a main system DAC if budgets allow.

 

[kenman345]

 
You are correct, sorry, that is a new product. I have read it will be better with a more advanced line stage (no opp amp). But for the money looks hard to beat.
 
But TBH I would look higher up the scale for a main system DAC if budgets allow.

I am actually looking at it for a secondary DAC. I use a Metrum Musette for my main but I use my laptop for music and my desktop to game and I have a mixer combine the two signals together. I find the desktop audio is dirty, very easy to hear the problems and an external DAC fixes it so I was thinking if I got the dac1101 then I could use it for my Desktop for my games and then as a portable DAC when travelling.

 

[Andrew Rieger]

Anyone have experience with the Mojo Audio Mystique V1.0? Used prices seem very reasonable. 

 

[astrostar59]

 

 
There is a huge and long standing thread on other forums, I think at computer audiophile.com and DIY audio. There are lots who have build it and you can get the info you need there.

You're thinking of the DIY board. The dac1101 is an actual product with the dac on a custom board that is in an enclosure and has a USB input. 

Yes that is a finished product. Looks interesting performance (potential) v price. There is a big DIY community on computer audiophile that has used the board in DIY DACs. I would be interested in a kit with a tubed output using this board.
 
Might be wrong, but I read from Lampizator owner postings that the board is used in the Big 7 and GG units. Can't confirm that so if not correct, please post.

 

[yawg]

  I am actually looking at it for a secondary DAC. I use a Metrum Musette for my main but I use my laptop for music and my desktop to game and I have a mixer combine the two signals together. I find the desktop audio is dirty, very easy to hear the problems and an external DAC fixes it so I was thinking if I got the dac1101 then I could use it for my Desktop for my games and then as a portable DAC when travelling.

An external DAC doesn't fix all problems. I have one and still get some clicks in my music from my netbook, I guess it's effing Windoze.
 
Playing that same music via that same ext. DAC from my Nokia N8 - no clicks, pure beautiful music.

 

[Beresford]

  An external DAC doesn't fix all problems. I have one and still get some clicks in my music from my netbook, I guess it's effing Windoze.  Playing that same music via that same ext. DAC from my Nokia N8 - no clicks, pure beautiful music.

What software / extra hardware are you using on your N8?   I have bought one which I want to set up to play music well.  Thanks.

 

[yawg]

 
What software / extra hardware are you using on your N8?   I have bought one which I want to set up to play music well.  Thanks.

No extra hardware. Playing my FLAC files directly from the N8 using QuasarMX works fine. With my amazing BossHifi B8 over ears it's loud enough without amp. When I play via my FiiO DAC/amp as a booster via the HP out the sound is even less dynamic. But when I use the USB out of my N8 (USB2Go via the supplied Nokia adapter) the DAC of my FiiO is enabled and the amp kicks ass. But apparently the built-in HP amp of the Nokia is powerful enough for my highly efficient 16 Ohm B8s, no big difference. More dynamics and volume with the DAC/amp on USB and tighter kick drums.
 
The N8 is a great audio device. A pity they discontinued Symbian. But there are people who love the Nokias and still write and upgrade new apps for them.

 

[glina]

As it seems, it's time to (re-)join the club. I've been having nostalgic moments after my long gone Cambridge Dacmagic 3 (Based on 2x TDA1305T chips, hybrid R2R and DS) and I just couldn't find that with liquid and explosive sound with any modern device I've tried. I currently own 5 DACs, including one based on the 2x ESS9028 Pro and one on the newest AKM AK4397. As good as they are, they may have to step away in favor of ...

The Valab/Teradak V3.1D. Well known on this forum, this is an 8x TDA1543 DAC with USB, re-clock, re-data and a reasonable power supply. It has a very basic passive analog filter and no output stage whatsoever.
First plugged in it sounded a bit nervous, but the underlying qualities were abundant. Nothing that some tweaks wouldn't fix.

1. Replaced 8x 100nF ceramic decoupling capacitors on TDA1543 with Panasonic ECHU 100nF film caps
2. Replaced 8x 10uF tantalum decoupling capacitors on TDA1543 with New old Stock (the NoS in a NOS DAC) Non-ROHS Elna Cerafine 33uF
3. Replaced the I/V resistors with Vishay Bulk Z-Foil. I had to change the value to 250R, as the originally mounted 340R were clipping the output above -3dB).
4. Bypassed the analog filter, the wiring is direct from 8xTDA1543 via a coupling cap to RCA.
5. Used Clarity Cap CSA 2.7uF for signal coupling (the best I could fit in the smallish housing). I could decrease the coupling caps from 10uF to 2.7uF knowing that my following stage is a high input impedance amplifier.
6. Last but not least, hooked up an oscilloscope to adjust the working point for minimal THD and clipping after the I/V resistor change.



This little box is really nothing short of amazing. It loses nearly nothing in detail and dynamics comparing to modern DACs, but beats them hands down with pinpoint imaging, coherency and natural midrange smoothness. My total investment in mods is around $50 and a few hours time, very well spent. Accompanying equipment is an Audio Note P2 SE power amp and Audio Note AN-E loundspeakers (talk about misalliance )

I can hardly recommend a better piece of gear to get a taste of NOS R2R.

 

[conquerator2]

So, I've recently acquired the inexpensive Audio-gd R2R11, which uses their own DA-8 R2R DAC module. I only sold my Chord Mojo recently and my previous favorite was a likewise R2R Theta Digital Basic II. I was not a huge fan of Schiit's R2R designs as I found their tuning less appealing than Theta's, which uses a vintage (TI) Burr-Brown vintage DAC chip, most similar to the recently discontinued and highly regarded PCM1704, which Audio-gd used in their previous flagship designs. I only heard the DAC-19 from their vintage designs which impressed me and a few of their DS designs which, while okay, felt into a similar category as the Schiit.
So, after selling my Theta and Mojo I was going into the R2R11 with a healthy dose of skepticism, owing to my mixed A-gd experience and low all-in-one price point.
Boy, was I in for a very pleasant surprise! Over the past days, this unit has made its place in my collection as one of the highest regarded units that I've ever owned (perhaps even listened to). The tonality with the included amplifier is spot on, very similar to how I remember the Theta and DAC-19 sounding like, but better detailed, with wider soundstage and just as much vintage goodness. The amplifier has ample power to drive most headphones and with the ones I've tested so far it sounded excellent. It has all the essential inputs (similar to the Mojo) and sounded excellent through the speaker outs with my monitors. The USB implementation is rock solid and as someone who's had many issues with their previous VIA USB32, performs flawlessly and sounds great. The ALPS potentiometer feels super smooth, there's low and high gain and it can be made slightly warmer sounding by adjusting a set of jumpers inside (I did not find this necessary myself). It runs barely warm to the touch and blends fairly well on a modern desk with its fairly small footprint.
For the asking price of $350 (well, closer to $450 if I account for shipping and VAT) I still couldn't believe it. Not only was the sound way above what I expected in the best case scenario (somewhere between the Mojo and Theta, closer to a DS device) but it also ranks as one of my cheapest, if not the cheapest audio gear purposes ever. Taking a glance at my profile, if I combine any number of amps and DACs together they always came out pricier and just not as good. To conclude, I am stunned and delighted that there's a unit like this available, and as much as it was a shot in the dark for me (completely new R2R design, new USB board, low price, mixed experience) I can safely say that this unit will stay here for a while and that I don't think there's frankly a better R2R DAC/amp combo out there right now in its price range and a few notches above it.

 

[drbluenewmexico]

I have been using a Mystique 1 DAC in my headphone testing system as well as my main full size living room system
for years now. It gives me the clearest most analogue like sound I've ever heard from a digital source. its much better
than high end CD players DAPs or up sampling DACs I've experimented with. I've also had Mojo Audio upgrade
an older Renaissance Labs DAC i got used, ten years old, with new state of the art parts and circuits. The upgrade
was cost efficient and spectacularly effective in improving sound quality.
I was one of those vinyl diehards who said that digital would never approach the purity and naturalness of vinyl.
i always described digital as a "bad zerox" of a pure mile long groove of vibrations Ben's DAC made me eat my words.
His DAC's equal or surpass the "analogue" sound of vinyl in ways which allow my brain to relax and experience
the music instead of the bits. I can't recommend Ben's work and Mojo Audios gear too highly!

 

[kvik]

I made a list of current Multibit/R2R DACs, maybe someone will find it useful.

 

[MojoAudio]

Amazing list of R-2R DACs.

Thank you Kvik.

A few notes though...

The CS8412 and PCM2707 are not R-2R DAC chips, but rather S/PDIF receiver chips. I would imagine that many of the DACs on this list might use the CS8412 S/PDIF receiver (personally I use the CS8416 S/PDIF receiver). That doesn't mean the 47 Labs DACs are not R-2R...likely with those S/PDIF receivers they are. It means they use an unnamed DAC chip in addition to those two S/PDIF receiver chips on your list.

The Wolfson WM8742 is not a multi-bit DAC chip, but a multiple single-bit Sigma-Delta converter. It does convert all sorts of formats of PCM and DSD, but ultimately the conversion is single-bit. So if that's the correct DAC chip, the Abbingdon DAC doesn't belong on this list.

And the LTC2753 DAC chip is very unlikely to be R-2R. The data sheet actually doesn't state specifically what they are, but in the size package they use, and considering what they are intended to be used for, it is quite unlikely. The LTC2753 DAC chip is using some type of proprietary "multiplying parallel input" 16-bit topology that is recommended to be used for: High Resolution Offset and Gain Adjustment, Process Control and Industrial Automation, Automatic Test Equipment, and Data Acquisition Systems (not audio). So I'm guessing the DIXO DAC doesn't belong on this R-2R DAC list as well.

Aside from those few notes, this is an amazing list.

Thank you for taking the time to put this list together and post it

 

[kvik]

Thank you for the kind words, and for the corrections, MojoAudio.

47 Labs: Model 4733 - You are right, PCM2707 is used as receiver chip, the DAC chip used is TDA1543. Model 4705 - Again, CS8412 has to be the receiver chip, unfortunately I am not able to find out which DAC chip is used. I am not able to judge, if the design suggests the DAC chip is R2R. I will try a bit more to find the chip used, before I omit the unit from the list.

Abbington: The unit appears to utilize two separate DACs, one for RedBook (UDA1305AT), another for everything else (WM8742). The former is multibit, I believe, the latter not, as you point out. I primarily included the Wolfson chip as additional info (about the second DAC).

DIXO: Here I basically just found the LTC2753 data sheet, and I am not skilled enough to judge from that, if this chip is multibit/R2R. No-one else seem to use it for audio, or refer to it as multibit, so I simply took the creators word for it. You might be right, that it doesn’t belong on the list.

 

[MojoAudio]

Since the CS8412 is a 24-bit 96KHz S/PDIF receiver I'm 99% certain that the 47 Labs is a true R-2R even if you can't find the specific chip it uses. I've never heard of a modern single-bit DAC using a vintage CS8412 receiver and most modern single-bit DAC chips have built in S/PDIF receivers and wouldn't require it. Likely the 47 Labs is using an older R-2R DAC chip such as the TDA1541 or TDA1543 since there is no advantage to feeding them 192KHz input.

There is literally no info on the UDA1305AT chip in any search I've done. People even commented "there is no info on this chip" that I found in the search. My guess is that it is not an R-2R chip since pretty much all of the vintage R-2R chips are well known. It is very likely that chip is used for other purposes, such as a receiver, digital filter, or demultiplexer that feeds the actual DAC chip.

The LTC2753 is not R-2R, but it has a form of "multi-bit" decoding since it has multiple Sigma-Delta converters running in parallel. I believe these multiple decoders are used as a form of error correction during data transmission. Quite an odd bird when it comes to audio DACs. I don't know of any other company using that DAC chip.

The Wolfson WM8742 also states "Multi-Bit Sigma-Delta conversion" on its data sheet. That is another term for "Wide-Band DSD" which is what recording studios use to lower the noise floor when editing, mixing, and mastering DSD. It is not the same as "R-2R" even though the term "multi-bit" is used to describe both. Note that for each bit you add your noise floor is reduced by 6dB. This is why Sigma-Delta DACs require such sophisticated digital filters, noise shaping, and upsampling (moves noise out of the audible ranges).

And the PCM1704 is not actually a pure 24-bit R-2R DAC chip. They can not match multi-bit resistor ladders beyond 20 bits according to what these companies tell me. The PCM1704 is in fact an ingenious hybrid of multi-bit R-2R and algorithms. They use two R-2R resistor ladders, one for the Most Significant Bits (MSB) and one for the Least Significant Bits (LSB). Then the ladder from the LSB is summed, significantly reduced in voltage, and "spliced" onto the the output from the MSB ladder using an algorithm. To me the PCM1704 has a sonic signature half way between classic R-2R and modern single-bit Sigma-Delta decoding. I still prefer the sound to any modern single-bit DAC chip

Something else to account for is tube output stages. Read the data sheets: most tube output stages have less than 90dB SNR. Since a 16-bit recording has a potential of 96dB dynamic range that would mean that no matter the resolution of the DAC chip that is used in a DAC with a tube output stage the output bit-depth resolution can not be greater than 16-bit Red Book. Sorry to burst anyone's bubble on that techno-fact

How come HD recordings still sound better on these DACs?

Because the editing, mixing, and mastering of these new HD recordings is better than the original Red Book release and not because the format is actually 24-bit.

That's why a well made 16-bit DAC, such as my personal "low budget" favorite, the Terra DAC, can out perform much fancier higher resolution DACs. The Terra DAC has no additional op amps, no tube output stage, uses a good quality external power supply, and much larger higher-quality output capacitors than most. A simple proven design that is done well. Almost identical to the circuit used in many of the more expensive TDA1543 DACs on the list.

 

[glina]

I see nothing what would suggest LTC2753 is a Delta-Sigma chip. In fact, the non-linearity characteristic and glitching is very much typical for R2R, so is the limited bit-resolution. Chance is, this could indeed be a nice audio DAC.

UDA1305AT is in fact the TDA1305T, a well known chip from the multibit era, although it's an odd one. It is a hybrid R2R/Bitstream dac with integrated digital filter. Some very successful commercial products such as Naim CD3.5, CD5 and Cambridge Audio Dacmagic 2, 2i and 3 used that chip. I used to own the Dacmagic 3 and it was a wonderful piece of gear, one of the best I've owned in fact.

Funny you should mention tube output dacs and TDA1543 only a few sentences apart. You very well know that TDA1543 has very poor noise and distortion characteristics, worse than 90dB even if using many parallel chips. This has little to do with perceived quality. I used to pursue parameters such as <120dB SNR in my amps and dacs, but 15 years into the hobby i realized each step puts me further away from enjoying music. I think this is exactly why we are now experiencing the R2R "revival", as well as vinyl and tube revivals. It makes me wonder if reaching technical (measured) perfection with discrete R2R DACs wont catapult as back to square one.