Dac Technology Mature?

I would love to hear an old Theta & Wadia compared to the new stuff.
probably a Viamak , too

I read about there stuff, but never heard

As close as I got was a Rotel 855

Is there going to be a lot of difference?

i look forward to the response

jeff

For me, I like my converters to be transparent - If I want color I'd rather do that in other areas of the audio chain.

To test the transparency of digital audio is actually pretty easy. You just have to make a digital copy of an analog recording (tape or vinyl, for instance) and do a double blind test to see if anyone can hear the difference. I believe such a test was done with analog tape but I can't seem to find it on google. Does anyone know about it? 

Mature? Yes. 
How far and how fast?
Getting out the CAL delta transport, the Sonic Frontiers Ultra Jitterbug and Theta Pro Basic IIa DAC for demo against my Oppo BDP-83SE. Will report how things “improved” from 1993 to 2010. 

The Linn Klimax DSM Katalyst is WOW sounding. Go
out and hear one. You will be drooling. All Klimax DSs can be upgraded to the 4th Generation DAC Linn make today. Also the older boards can be Renewed to play in other rooms. https://www.youtube.com/watch?v=L1t6hZdKXLw  https://www.youtube.com/watch?v=rPGKEV7v7T8

Any discussion about DAC Technology should include the developments made by Rob Watts and John Franks of Chord Electronics. Custom Coded FPGA chips with over 500k lines of code replace off the shelf DAC chips. Thier new Hugo TT 2 also receives the benefit of an upgrade from 4-element design to a 10-element design, which works in harmony with the radically upgraded FPGA and code.  In comparison to the 256-tap filters that traditional chip DACs may run, Hugo TT 2’s more powerful Xilinx Artix 7 FPGA, custom-coded by Chord Electronics’ Rob Watts, with 86x 208MHz cores running in parallel to create an advanced 16FS WTA 1 filter with 98,304-taps. That horsepower does more than just connect the dots of data to create an analog waveform, it creates a soundscape.

Chord seems to have the only new DAC technology making an appearance with its DAVE & upsampler taking on the $100,000 plus DACs at a fraction of the price. It appears to be an updated version of what made Wadia famous in its day that everyone else has given up on as an approach. Alan Sircom, the editor of HIFI+ prefers DAVE to the big boys.

Great analogue stages really matter, but apparently, the great tube gear designers aren’t going there. i.e. could you imagine one designed by Vladimir Lamm?

768 might make a meaningful difference that may get people to start paying attention but I suspect it will be a multiple of even that number, that will bring back some semblance of the resolution available on really, really good vinyl playback. Sceptics here need to make the comparison before saying otherwise.

As someone who's done a complete 180 over the past few years to jump fully back to vinyl because of my dissatisfaction with digital, I for one, sure hope DAC technology is not mature.  In our frequent get togethers, just about every person raves over our even mid level analog rigs providing much better sound and happiness than most of the highly touted digital implementations we also own

whitestix298 posts08-04-2018 10:08pm

improvement over, for example, the internal DAC in the Oppo 205.  

Hmm, I thought my Oppo 105 sounded excellent (pretty sure it has the identical dac section as the 205) until I replaced my preamp with an Audio Alchemy DDP-1 Dac/Pre, just for the pre, but once I got around to trying the DAC portion I was shocked that the AA DAC was light years ahead

I did own a California Audio Labs delta sigma some 30 years ago.

IMHO, one of the main issues/obstacles is the transmission line from trans> dac> pre. One of the few cable mfgs who actually knows what he's talking about is WireWorld. His Mini Eclipse series is a serious bargain, as are his power cords

Another is how well the AC is filtered. I have a Core Power Tech 1800 plugged into a 20 amp dedicated line 

In short, "Yes" to the OP

But:
Tube DACs are still evolving, though at a slower rate than 10-20 years ago

SS Dacs will continue to diversify on tried and true principles, but now with more hybrid designs (not just tube/SS, but now SS and Class D) and now incorporating more R2R designs

Class D is as mature as it has ever been right now, but will continue to get better as the tech progresses (eg, from primordial switching tech to ICE modules, to NCORE modules TOTL)

That said, I found an old Sony CD/DVD player from 2000. MSRP = $3000, mine for $40. has a R2R CD DAC and is just a smidge below the SQ of my $3000 Sim CDP (2005) and $5000 Bel Canto 3.7 DAC (2015)

More specifically,

”The principle of sigma-delta modulation, although widely used nowadays, was de- veloped over a time span of more than 25 years. Initially the concept of oversam- pling and noise shaping was not known and the search for an efficient technique for transmitting voice signals digitally resulted in the Delta Modulator. Delta modula- tion was independently invented at the ITT Laboratories by Deloraine et al. [11, 12] the Philips Research Laboratories by de Jager [10], and at Bell Telephone Labs [8] by Cutler. In 1954 the concept of oversampling and noise shaping was introduced and patented by Cutler [9]. His objective was not to reduce the data rate of the signal to transmit as in earlier published work, but to achieve a higher signal-to-noise ratio in a limited frequency band. All the elements of modern sigma-delta modulation are present in his invention, except for the digital decimation filter required for ob- taining a Nyquist rate signal. The name Delta-Sigma Modulator (DSM) was finally introduced in 1962 by Inose et al. [25, 26] in their papers discussing 1-bit converters. By 1969 the realization of a digital decimation filter was feasible and described in a publication by Goodman [16]. In 1974 Candy published the first complete multi-bit Sigma-Delta Modulator (SDM) in [6]. Around the same time the name SDM was introduced as an alternative for Delta-Sigma Modulator and since then both names are in use. In this book the oversampled noise-shaping structure will be referred to as SDM. According to the author SDM is the more appropriate name since the integration or summing (the sigma) is over the difference (the delta).”

Let's go back to 1948 at Philips a couple of geeks there started it all off.
https://ibb.co/fGLL89

Cheers George

Archimedes has firmed up at 2 to 1 odds, but I heard someone was offering 200 to 1 odds that Plato invented Delta Sigma theory. How do I get some of that action?!

The concept is ancient. Calculus comes from mid 17th century. Often it is the implementation or application that is tricky. Da Vinci invented the concept of a helicopter but it wasn’t possible to build one until technology was sufficiently advanced. 

This just in! Read em and weep!

The (delta sigma) technique was first presented in the early 1960s by professor Haruhiko Yasuda while he was a student at Waseda University, Tokyo, Japan. The name Delta-Sigma comes directly from the presence of a Delta modulator and an integrator, as firstly introduced by Inose et al (Japan) in their patent application.

@georgehifi Interesting. Here is a list of Patents assigned to Vimak Corporation - https://patents.justia.com/assignee/vimak-corporation
That list includes the following patent -

Multiple clock signal generator apparatus Patent number: 5266908 Abstract: A digital-to-analog converter--preamplifier apparatus serving as an interface between a source of digital audio signal data and an amplifier is disclosed. A digital stage receives multiple digital audio signal inputs, a selected one of which is analyzed by a digital audio interface receiver, processed by a digital signal processing device and a delta-sigma modulator prior to passing to the analog stage for conversion from the digital domain into left and right channel analog audio output signals. Volume control is performed on the audio signal in both the digital domain and the analog domain in order to optimize performance and minimize noise. The present invention automatically adjust for input word lengths of greater than 18-bits.

Type: Grant

Filed: January 26, 1993

Date of Patent: November 30, 1993

Assignee: Vimak Corporation

Inventors: Michael A. Koulopoulos, Russell A. Siggelkoe, Thomas R. Hegg

What I am certain of is that Vimak held relevant patents for the only truly discrete implementation of a Delta Sigma dac i’m aware of. And whilst they may not have invented Delta Sigma theory, they developed it to it’s ultimate potential using proprietory technology in the DS-1800Mk2.

I do believe we're both wrong.

From Stereophile: " Philips invented the delta-sigma modulator in the 1960s, and were the first to apply it to CD players in its 1-bit form (switched-capacitor based)."

Cheers George

georgehifi 08-08-2018 6:35pm
4,118 posts

BTW: I remember that maybe Technics invented the first Delta Sigma, and they called it MASH.

Cheers George

I was told that Vimak invented Delta Sigma theory by one of the few high end audio engineers who has serviced the incredibly complex DS-1800Mk2 dac. As I understand it, Vimak Corporation hold the design patents for the technology, or atleast did (as patents expire). The other factor supporting that contention is that Vimak are the only manufacturer to have ever implemented a fully discrete Delta Sigma dac, as opposed to the usual chip-based design. However i’m happy to be proven wrong if anyone has information to the contrary.

Dac Technology Mature?

I know this is blasphemy, but Is Dac technology reaching maturity.

I think it’s coming back around again to R2R Multibit even if now it’s discrete as there are no chips being made because of cost.

Vimak invented Delta Sigma dac technology

BTW: I remember i think that "maybe" Technics invented the first Delta Sigma, and they called it MASH, in the 1989 SH-X1000

Cheers George

@bachish   

You can add add links to your post with the “link” button. Just copy and paste the link to your soundcloud file.

@shadorne 

Thank you, shadorne!  Yes, the Benchmarks have a great reputation and are often used in classical recordings.  Out of curiosity, do you transfer your vinyl to digital through your Benchmark? That would be a fun listening test to compare. I agree that the converters have substantially improved over the years. And from the recording side, to get a decent sample rate conversion back in the 90s, I had to take the recording to a mastering studio and pay a couple hundred dollars for what I can do myself even better  today.  Everything, it seems to me, has really improved.

I use a Mytek ADC 96/24 for recordings. As nice as that converter is, Mytek has even made some improvements in their current models. But I like my Mytek paired with my ribbon mics. The Mytek is uber detailed but retains the lovely smooth, silky sound of the ribbons. I tend to spend more on the recording side of things then monitoring or listening side (I have to prioritize somehow or I'll go broke! haha) so my DAC isn't as fancy as yours but just ordered a Grace m900 for a DAC. I have been using a lower end Schiit.  But the m900 came recommend for its transparency and detail, which is what I need for classical recordiing and for which Grace is known, and it's only $499 - about my price limit at the moment.  

I know now what you mean about trading detail for a more euphonic sound.  Hey, it's exactly what the arts have been all about for centuries - give the viewer or listener something that presents life through an ideal - a better world, an ideal place.

Since you have such a nice set up, is there a way for me to embed one of my recordings from SoundCloud on here? They compress the audio but it sounds better than YouTube at least. I'd love to get any feedback from you all. It's a jazz recording using minimalist recording techniques - just two ribbon mics in Blumlein array through a high end mic pre (hand made), into my Mytek ADC. Pure and simple.  Good players too.

@bacshish

Congrats of first post and welcome. I cannot agree with you more. I am happy with the transparency of my Benchmark DAC 3. I would be happy with any number of leading DACs - they all sound really great. Leaps and bounds better than the mid 90’s and the latest have an edge over mid 2000 DACs that makes them as close to vinyl as I have ever heard. Other DACs require more babying with special cables, various filters or reclockers etc - so I like the convenience of the bullet proof reproduction from Benchmark - so unlikely to replace it.

For euphonic sound I use a McIntosh preamp - well known for their crafted sound. I don’t use the built in DAC as it requires a Schiit Eiitr or similar to work optimally. I am willing to trade a bit of resolution from the DAC 3 but gain in some pleasant tube warmth - especially at low volumes. McIntosh seem to have achieved a pleasant balance to my ears. Some preamps like ARC are too much like SS (for my taste). Some preamps like VAC are too euphonic (for my taste). I am looking to audition an EAR 868PL in my setup but I fear it may be a little overly euphonic for me.

Hi, First post here...professional classical musician and recordist as a serious hobby for 20 + years. So I’ve been on the other side of the audio process, so to speak, and am just curious to read what the audiophiles are up to.

So hello everyone.

Here’s my take on ADCs and DACs - IMO, they have already attained a level of near perfect transparency (assuming a professional level of converters designed with that goal in mind).

On top of that, the sample rate conversion has become stellar. For instance, when downsampling from 88.2 or 96 Kh, 32 bit float to 44.1 16 bit dithered and noise shaped in Izotope RX, the original and down sampled version with a phase reversal null perfectly in my DAW in the audible rang. Listening back it’s dead silent at full volume except for a slight bit of white noise (the dither and headphone amp noise).

So if it is transparency you are after, they are pretty much there already. Probably just small improvements are on the way.

If you are looking for a more euphonic sound that can match analogue, then I’m sure there is much more to come.

No question DAC technology has matured.  I had a half dozen DAC in the past several years priced under $1K and recently picked up an Ayre QB-9 DAC and the SQ improvement was stunning.  The fact of the matter is that you have to spend north of $2K to hear much improvement over, for example, the internal DAC in the Oppo 205.  

MickeyB;

Good Point
I know my ears will not keep up.

A bunch of interesting points in the discussions

jeff

 

DAC technology will continue to improve but the big question is will our ears continue to hear the micro improvements? I know my carpenters ears will not. I'm fine with a Grant Fidelity tube dac. 
Though my friend has a Lumin D1 and I was very impressed. 

@ejr1953 I agree with you that dacs have greatly improved over the years, but not because of radical improvements in dac chips. More so for the reasons I eluded to earlier. Component and material quality, psu’s, upsamplers, clock accuracy, boards, tolerances etc have all improved over time, as has manufacturing equipment (incl: computers).

frozentundra OP 08-04-2018 11:07pm
105 posts

Gents;. And Ladies!

You are all wrong....

Then why ask for input if you could answer your own question & were not well disposed to alternate points of view? We could have all been spending our time on something more useful like reading a book or doing housework..

Of all the components in a high-end audio system, IMO the DACs are the ones currently enjoying the most improvements.

Certainly, as time marches on, amps, preamps, speakers, etc. are improving, but IMO those technologies are pretty much "mature".

One thing I've come to appreciate is how much improvement a DAC exhibits with the quality of the AC power it's being fed.  The more I learn about DACs, the more I appreciate how much the timing of the bits is important to the quality of the analog signal it outputs.  I believe the better DACs will have better handling of the timing of those bits (more attention to the internal clock designs), and therefore produce better sound.

Gents;.  And Ladies!

You are all wrong.....( catch your attention?)

100 people & 1000 opinions.  
 It's just like it was stated in AG a few years ago.( above comment)

I'd love to get an opinion of a manufacturer, Steve N?

 I had an older Rotel 855 Cd player & it died
When I upgraded to a Peachtree Pre & ESS DAC is was a noticeable positive change

I think the last 5-7 years have brought about serious changes in tonality, more full body vs bright.
I do think big changes are stabilized

I continually look at Dac output signals vs inputs in Sterophile
They look nasty, but still sound pretty good

Elizabeth;  Marantz SA-10 vs Ps Audio Directstream?    Any opinions?


jeff

As digital music playback starts with a PCM or DSD 'blueprint' (of varying sample rates and bit depths) of a load of electrical signals that are the building blocks of this thing called music then the DAC is a rather important part of the picture to put it mildly as it actually builds the music brand new every time you hit the play button. These two formats are very different and yet I'm not convinced either is being converted to their respective bests. Instead we have DAC's that are primarily PCM or DSD based and convert the other format to their particular format, or we have hybrid DAC's that claim to be doing everything. The quality is extremely good but being pedantic it would be great to hear music through a dedicated DAC.

Nothing is fully mature until it dies.  This can apply to both life and audio.  As long as we are alive, we are evolving....some slower, some faster.

DACs have definitely become more stable, but it’s the “transport” that’s quickly evolving.  Network based systems such as Roon is where the future of digital is going, and that’s a moving target....and lots of fun.

I think some members are confusing terms, as in adolescence > maturity > dotting off to the nursing home. I reckon it’s fair to say that after 50+ years of constant development, DAC technology has reached “maturity”.

Dac technology has been largely worked out for 20+ years. For example, Vimak corporation who invented Delta Sigma technology implemented the only truly discrete Delta Sigma dac; the DS1800Mk1 released 25 years ago which was incredibly complex and over-built. Now, Delta Sigma dacs are implemented in miniaturized chips. And in the process I think they lost something actually.

But that doesn’t mean DAC technology is standing still, or that manufacturers aren’t innovating. Data Conversion Systems proprietary ring dac and APL Hifi’s proprietary DSD dac are good examples.

Listen to a DCS Rossini and tell me DAC technology is not much better than 5 years ago.

bigkidz                                                                                                                     08-04-2018 11:51am
1,646 posts
Picking up on Shadorne’s comment, remember it’s all about implementation. And that comes down to the skill of the designer and the company’s manufacturing capacity. As I said, the digital part (incl: the dac chips) in total would contribute no more than about 15% or so to the complete sound. The psu and analog stage, combined with pcb layout matters more.

Quote citation missing, but it’s all good ;).

Digital is still in its infancy, IMHO.  It will continue to improve for a long time to come. 

Very Interesting.  So I guess my DAC with a 30lb power supply would be considered???  Upgrade for future???  PCB layout???  Hmmm what about point-to-point wiring, copper chassis, discrete R2R, Caddock resistors, V-Caps, DHT design?  

Picking up on Shadorne’s comment, remember it’s all about implementation. And that comes down to the skill of the designer and the company’s manufacturing capacity. As I said, the digital part (incl: the dac chips) in total would contribute no more than about 15% or so to the complete sound. The psu and analog stage, combined with pcb layout matters more.

melbguyone - where are you coming from? You are so wrong about ps audio. How many dacs do you know of use FPGA? How many dacs do you know can add MQA thru software and at no cost? Their DS dac has the bridge which is outstanding technology where very few dacs support. You can have the old technology of using USB and having a music server or computer in your audio room. Most new releases of their software improve the SQ not decrease it, but what’s nice, you are in control, use the latest version or not. How about buying a $1500 board for your dac for MQA or another type, and you don’t like it? Can you send it back?

I agree with Eric.  I have an AD1955 in my Emotiva pre-amp and I noticed no real difference on hi-res files, but mp3's and Redbook CD's are much better sounding.

In my experience with any machine, there is little to be gained by chasing the yearly updates. Whether it is a car, a bike, or an amp, there is an improvement but is it enough to warrant switching to the "new model" everytime something gets another mosquito wingbeat per ms? NOt for me.

When you compare products between companies it is the same thing, some will be a wingbeat ahead. Chevy, Ford, or MBZ? Depends.

Every ten years, go ahead and update if that's what you want to do because there will be quite a difference. I know that attitude seems to be anathema to many audiophiles, but it is sensible. Ten years is arbitrary.

@maplegrovemusic It's not about being cool, there is a lot more to a DAC than simply D to A conversion. A good DAC needs a good solid power supply and good analog output stage to truly sound good. Any designer would tell you that, and frankly that goes for other gear not just DACs in terms of a good power supply.

Lots of opinions;

I just did a comparison of my Meridian Explorer2 with a Exogal Comet DAC.
Many thanks to one of our Audio Group for alowing the comparison.

I have found ( to my ears) that a true comparison needs to be done on a system that you are " intimately familiar with and its sound quality"

We compared both & MQA, too ; via Tidal.

I found it easy to hear more details, more depth and more width of soundstage.  Tonality was different, but not huge.
It was maybe a designer preference?

AND it was my system. It is easier to hear differences on the home system that I've listened to a lot.

When I go to my buddies houses, they all sound great, but with variables due to their individual tastes
I have to listen quite a while longer to detect differences.
My buddies have great ears & great systems.
I'm kinda the yellow belt & they are the black belts, but I'm learning...

My guess, Is I can hear 10-15% more details/ resolution in the better models.

Anyway, my opinion

My goodness, what a strange hobby

jeff

A dac is a dac is a dac . Plain old inexpensive days will feed you the data bit perfect . Not cool enough you say ? Spend more where the designer has added more treble , more bass , etc .... And a fancier case the more you spend .

Hey my 20, 23 actually, year old DAC sounds just fine thanks! Love that old R2R technology, wedded to a robust power supply and tubed analog output stage of course.

Same here. Old R2R; check.  Tube output stage; check.  Robust power supply check.  The only difference is that mine is *only* 16 years old.  As I stated in another post (I'll respond to that one shortly), my old 16 year old DAC sounds very close (but slightly better in some ways) than my newer DACs.

Hey my 20, 23 actually, year old DAC sounds just fine thanks! Love that old R2R technology, wedded to a robust power supply and tubed analog output stage of course.

Mature, yes, in the sense that you can engineer tube amps that sound a lot like solid state, and solid state amps that sound a lot like tubes.  W.r.t. DACs, unless you go out of your way to engineer something that sounds a lot different from the crowd (which may or may not be a good thing), there's a lot of convergence doing on: different topologies, different chips, etc., end up with a sound that is really pretty similar--and which is only picked apart by audio reviewers looking for something to hang their hat on.

Mature?  I'd say exactly the opposite.  Although it's always existed, the differences between the delta-sigma DACs and the R2R and NOS multi-bit processors seems to be in its relative infancy.  Heck, we're still reconciling the convergence of tubes vs. solid state, and that's been going on for 40 years.  And digital technology is progressing at a faster pace than analog ever has.  So, five years from now I'd expect the digital processing landscape to look very different than it looks today.  The analog world, not so much.  So I guess mature is relative, and to me digital is the petulant teenager bursting with energy and embracing change in a fast-changing digital world.