[mresseguie]

Since this is the Solid State Circle, let's limit this thread to SS DACs. They can be NOS, R2R, Oversampling, DSD, MQA, etc. There's no price limit. You can mention a $30 DAC (if it exists) or a $50,000 DAC. There's a plethora of new DACs out there.

Here are a couple that I've been oohing and awwing at lately:

Soekris 1541 R2R DAC and Nuprime Evolution DAC. I have not heard either of these, but they seem to get great reviews from audiophiles who own them. Have you heard either? What were your impressions?

Michael

[S Clark]

"They can be NOS, R2R, Oversampling, DSD, MQA, etc." 
For those (few) of us that are not really into digital,  please define your terms and acronyms.  What exactly is oversampling vs NOS?  I assume R2R isn't reel to reel as I usually interpret it to mean. 

[Jon L]

Since this is the Solid State Circle, let's limit this thread to SS DACs. They can be NOS, R2R, Oversampling, DSD, MQA, etc. There's no price limit. You can mention a $30 DAC (if it exists) or a $50,000 DAC. There's a plethora of new DACs out there.

After all these years, I have formed an opinion that in terms of pure subjective sound quality, DAC technolocy advances since say the PCM63/UltraAnalog D20400 days have GREATLY been exaggerated 

[Early B.]

The damn digital era -- it screwed everything up. You gotta be a tech nerd to understand modern day DACs. The solid state ones come with "filters" to give them different flavors. It's annoying to flip through them to find out which settings sound the best. What happened to "plug & play?" 

[WGH]

I use a Van Alstine FET Valve Hybrid DAC (discontinued), it has tubes so I can't talk about it's sound but a few years ago we compared the Van Alstine DAC to the more expensive PS Audio PerfectWave MkII DAC in two different systems and could hear zero differences. The only way we could hear a difference was to use the digital filters built into the PerfectWave, gritty digital recordings made in the early days can be ever so slightly altered to make them listenable.

[Big Red Machine]

I'll bet there are plenty of $1000 dacs that can compete with my $10k dac these days. We should have a GTG and bring in some price points and technologies and do a comparison event. That would be fun. I've always wanted to try one of the newer resistor ladder units being made these days as compared to the earlier days.

Jon's on it. These chips are so close today that the pleasantness of the unit comes in the power supplies and analog output circuits and how they are done. A resistor here, an inductor there, …..

[timind]

After all these years, I have formed an opinion that in terms of pure subjective sound quality, DAC technolocy advances since say the PCM63/UltraAnalog D20400 days have GREATLY been exaggerated 

I believe the best redbook I've heard was my old Resolution Audio CD50 with dual PCM63s. If that player had a dac input, I would probably still use it.

[mr_bill]

After all these years, I have formed an opinion that in terms of pure subjective sound quality, DAC technolocy advances since say the PCM63/UltraAnalog D20400 days have GREATLY been exaggerated 

I'm with you.....

[Jon L]

I believe the best redbook I've heard was my old Resolution Audio CD50 with dual PCM63s. If that player had a dac input, I would probably still use it.

By God, that brings back memories of my Resolution Audio Opus 21 CDP, which DID have spdif input, and I can't recall why I sold it other than the continual search for the next-best-thing in digital.  It used the PCM 1704 ladder DAC chips, which have now become so sought-after! 

Opus21 by drjlo2, on Flickr

[rollo]

  Yes the gap has narrowed a bit however there are still big differences in performance/features of different priced DACs. Depends on how they are used can make ALL the difference. If using a dedicated transport @44.1 then a server the quality can be big. Using a DSD DAC with music recorded in DSD a bigger difference in sound quality.
  Some DACs are voiced, some are not. R2R, Chip it is the end result in tonality, harmonic structure that matters.Higher price usually correlates with better sound. If that extra bit floats your boat and you can afford it. Go for it. If not thats cool as well.


charles

[MttBsh]

For the last few years I've been using a Schitt Ygdrassil which I found to be far superior to previous DACs I've owned such as Eastern Electric, Audio Note, Monarchy and others. I have a feeling that for around a grand the Digital Amplifier Company (DAC) DACs may be the ones to beat in terms of sound quality for the money.

[JohnR]

"They can be NOS, R2R, Oversampling, DSD, MQA, etc." 
For those (few) of us that are not really into digital,  please define your terms and acronyms.  What exactly is oversampling vs NOS?  I assume R2R isn't reel to reel as I usually interpret it to mean.

NOS = non-oversampling. Most DAC chips these days (and for a long time) oversample i.e. convert the incoming digital data stream into a higher multiple, like 44.1 to 352.8 kHz. Arguably the oversampling filter is not perfect, which is why a modern trend is to oversample in the computer (for some reason, this is called "upsampling") where you have more compute horsepower available, and then feed the DAC the highest possible sampling rate. NOS DACs don't oversample. However it means that - by default - they have a rolled-off frequency response conforming to what is known as the sinc function.

R-2R = resistor ladder - https://en.wikipedia.org/wiki/Resistor_ladder. This is an old-fashioned (or now, "retro") way of converting from digital to analog, which is basically what you would come up with if you were starting at the beginning. R-2R DACs tend to have a lot of distortion components, a sort of "distortion grass," with the level of it depending on the accuracy of the ladder.

Oversampling - I guess I assumed that was known above. This is converting one sample rate into a higher one. Like any conversion process, it's not perfect.

DSD = direct stream digital. This is a single-bit representation of the digital signal - https://en.wikipedia.org/wiki/Direct_Stream_Digital. It consists of a stream of high-frequency pulses, where the signal value is represented by the density of the pulses. It’s the format that SACD stores data in, I believe. When passed through a low pass filter, you get the analog signal. However, you also get high-frequency noise, which is why you now get higher rate versions of it called e.g. DSD128, DSD256, and so on that push this noise up past the audio band. (Normal DSD is then known as DSD64, where 64 is the oversampling ratio.)

MQA = Master Quality Authentication, a proprietary technology that came out of Meridian Audio. It’s been controversial, but the key claims are that 1. High-res sample rates can be represented in a lower sample rate stream, and 2. That “errors” in the AD and DA conversion process are somehow fixed by the MQA decoder so the end result is the same as the “Master”. The latter part requires licensed hardware; the first part can be done in software with e.g. the Tidal player. It is a lossy process i.e. you will never get back out exactly what went in.

[timind]

By God, that brings back memories of my Resolution Audio Opus 21 CDP, which DID have spdif input, and I can't recall why I sold it other than the continual search for the next-best-thing in digital.  It used the PCM 1704 ladder DAC chips, which have now become so sought-after! 

Opus21 by drjlo2, on Flickr

That's what I replaced my CD50 with:



I used it as a dac for quite a few years. Sold it about a year ago. It was one of those very easy sales.

[S Clark]

Thank you JohnR.  I seldom listen to digital, and never really beyond a cd player, so my questions were sincere.   
Although I had looked up much of it on Wikipedia, your explanations were helpful.   So is basic sampling the selection of a data point along a string at a particular rate?  For example, taking a particular number of points at a stream of data flowing at 44 100 bits per second?

[JohnR]

There are two parts to analog-to-digital conversion. First is sampling, where you capture the value of the signal (i.e. the analog voltage) at regular intervals in time e.g. 44,100 times a second. Second is quantization, where the (theoretically) infinite resolution of the signal value is reduced to the resolution of a finite digital word e.g. 16 bits. The first can theoretically be recovered exactly within the passband i.e half the sample rate, the second loses information. (The question then is whether any of the lost information was useful anyway, something audiophiles are prone to forget...)

The result is a (quantized) discrete-time signal, which has a spectrum that has infinite multiples of the original spectrum. Which is why a low pass filter is (usually) considered necessary in the digital to analog convertor and the reason for oversampling in the first place (the analog filter is simpler).

[mboxler]

A plug for the little guy 

$8.00 PCM5102 DAC with I2S input. 

[mresseguie]

A plug for the little guy 

$8.00 PCM5102 DAC with I2S input. 

I had no idea. How does it sound? [I know. How does one describe how any DAC sounds?] Do you use this DAC?

[mboxler]

I had no idea. How does it sound? [I know. How does one describe how any DAC sounds?] Do you use this DAC?

Sounds pretty good.  This was mostly a learning project, as I had no idea what I2S was.  I was going to add a small Class D amp and put in a small chassis, but haven't yet. 

Actually, this little project led me to understand S/PDIF as well.  USB is still confusing.  Trying to keep the old brain working.

Mike

[KLH007]

I'm really enjoying my new Bricasti M3 with network board, no more USB cables and dongles just Ethernet only to a network. Big improvement over the Comet and at twice the price expected.

[JackD]

For a Solid State DAC I've settled on the Aqua La Voce S3 for the last year. If I get the urge for the tube sound I swap in the Musical Paradise MP-D2 Mk III Deluxe.