[Freo-1]

This has me buffaloed.  I've been auditioning various CD/Blu Ray/DAC combinations for some time, and while the performance in general has improved with age, the one DAC that I keep coming back to (and will not give up) is a vintage Wavelength Audio Cosine NOS unit.  This sports the TDA 1543 Select grade DAC, employes no oversampling, and has a single 6GM8 tube buffer out to transformers.  The unit does not have the hyper level of detail many of the new 32 bit SABRE DAC's, but what it does have in spades is a natural sound that is very analog sounding, with not a hint of what most folks complain about digital sound.  It almost reminds me of a high end Reel to Reel unit of days gone by. 

So, the question is, why does such a vintage unit still sound so good?  Is it the NOS approach? 


 I've been thinking of getting a Metrum DAC, as I am intrigued by their design approach

[rodge827]

So, the question is, why does such a vintage unit still sound so good?  Is it the NOS approach? 

It is NOS done very well and yes the NOS approach will get you the most natural sound.

The best dac I have had was the Audio Note Kits 2.1b NOS Dac. The best thing about the Kits dac is that you can build it the way you want to.
We way upgraded the ps, used AN Silver Coupling caps, and a lot of BG caps on the dac board. 

[Folsom]

That chip still competes up into the tens of thousands of dollars level.

New DAC's are more advanced, but ultimately just because more technology is happening, that doesn't mean the sound is better per say. It might be different, comparable, but better is subjective. As DAC manufactures have found out, people are sensitive to things they aren't sure about measuring, at levels they didn't think were applicable to human, etc. It's not easy to understand.

Ultimately the signal is AC, from any DAC. Old DAC's don't leave gaps, but how they fill them could appear more crude since they often do less points to "connect the dots" with. They're still connected.

[Freo-1]

Good feedback, guys.  Thanks.

Take a look at this review.  There is a set of waveforms that make it appear that the NOS approach is superior.  Makes one wonder why it is not employed more often?

http://www.6moons.com/audioreviews/metrum/1.html

[volitanspine]

I am no engineer, so I cannot claim to explain what it is about NOS DACs that makes them sound so good. I own a Metrum Octave Mk II. It is the most satisfying DAC I have heard to date. It is the least digital sounding converter I've yet to hear. It has plenty of resolution, great timing, pace, and does a surprising job in bringing a palpable presence to the music I play. I have a good vinyl setup which does a better job with decaying sounds and gives an even more palpable realism to the music, but my Octave is no slouch in comparison. I used to listen to my Sabre based DAC mostly as background music, but I listen to my Octave with as much focus and enjoyment as I do with my turntable.

[Ericus Rex]

In my experience the 'latest and greatest' dacs have been hyped up to be a far bigger advance in sound quality over an older dac than is the reality.  I once compared my old Rega Jupiter player's dac (considered ancient at the time of comparison) with a new Benchmark DAC1 (the greatest thing since sliced bread at the time) and the differences were so subtle that I kept the Rega a few more years until I got my SACD player, which was a MUCH bigger advance in sound quality over redbook than any change of DAC I've ever heard.  Yet all these dac reviews make it sound like the technology has made "incredible" advances in the past few years.  There's been improvement, no doubt, but I'd have to change the word "incredible" to "subtle".

Just my humble, and usually wrong, opinion.

[Jon L]

So, the question is, why does such a vintage unit still sound so good?  Is it the NOS approach? 

Nah, I've heard plenty of TDA 1543 based DAC's (single, stacked, etc) that are not so great.  The Cosine was a premium DAC costing like $3500 (10 year ago money) utilizing simple I/V stage with tube output, Magnequest transformers for choke, output, etc.  These are probably the reason it sounds so good to you frankly.  I wish more manufacturers would take this kind of approach with SOTA chipsets like Sabre instead of sticking a bunch of op-amps after the DAC chip.   

[dpatters]

I am no engineer, so I cannot claim to explain what it is about NOS DACs that makes them sound so good. I own a Metrum Octave Mk II. It is the most satisfying DAC I have heard to date. It is the least digital sounding converter I've yet to hear. It has plenty of resolution, great timing, pace, and does a surprising job in bringing a palpable presence to the music I play. I have a good vinyl setup which does a better job with decaying sounds and gives an even more palpable realism to the music, but my Octave is no slouch in comparison. I used to listen to my Sabre based DAC mostly as background music, but I listen to my Octave with as much focus and enjoyment as I do with my turntable.

I also replaced my Sabre based EE Minimax with the Metrum Octave and never looked back. Very non-fatiguing presentation of the music.

[*Scotty*]

You might find an Auralic Vega DAC an interesting contrast to your TDA 1543 based DAC. I briefly had one in my system and was impressed with the harmonic completeness it had, it sounded like the entire instrument was present. Vocals were also well fleshed out and not thin sounding.
Scotty

[bardamu]

Hello,
Blame it on the bonus that the salesmen are getting. The average seller doesn't care if you walk out the store with a device that maybe just has some extra gimmicks but will sound not better and sometimes even just worse than the thing you just did put on ebay.
They know the brands that will give them a bigger profit margin. So that is what they wanna sell to you.
With help of the magazines who did kind of brainwash you they can easily guide you to the product THEY wanna sell and not to the thing YOU wanna buy. Of course now it isn't the magazines anymore but all the electronic websites that guide you.
Just buying what you like is already very hard. Knowledge didn't improve that much compared to the era where people use to read books.
If you prefer your 10 year old Dac so be it ( mine is even older Curcio) Just spend your money else where.
Sincere greetings, edward

[Freo-1]

The reason I pointed out the NOS approach is related to the signals referenced in the review linked above.  It seems as if the non-oversampling method produces a set of cleaner analog waveforms.  Jon L also brought up good points about the construction methods used.

I also had a Oritek Audio NOS (Version 4.1) that I gave to a buddy, and that sounded very smooth and analog-like as well.  Makes me wonder what all this oversampling is supposed to achieve?

[Folsom]

Most DAC's sound terrible without good power. Battery operations make them very smooth, but don't have the sparkle some like, found with AC. The cheaper the DAC the cheaper the power supply delivery to the actual chip. Then output capacitors are important too. There's almost nothing between the chip itself and your other equipment. Depending on the unit it isn't often more than two capacitors, some tracings, and your IC's. Which means all the stuff before the chip defines the difference between the $20 1543 and the $3500+ 1543. It's a fair amount of parts, doing different things. It's amazing how many different variations there happens to be. I'm still a huge fan, and wish I could get one of Peter Daniels in the ultimate formation, USB input. Maybe one day I'll just build it by hand.

It's ok though, I just listen to vinyl...

[gregfisk]

I have listened to several non NOS dacs and was never happy with the sound they produced. They all sounded bright to me and very digital. I currently own two NOS dacs, a Metrum Octave in my main system and a Havana in my beach house system, both of them sound very analog to me. The Havana is very lush, warm and musical, but lacks a bit of detail, the Octave is not as lush, still warm but has more detail. I have not listened to a single dac that was not a NOS dac that I could listen to for very long before fatigue set in. Of course this is just me, so the usual disclaimers apply.

[Quiet Earth]

Here is a paraphrased excerpt from the owner's manual of my NOS DAC. It explains in laymen's terms why the NOS approach is better :

"Regardless of the theoretical advantages of over sampling, noise shaping, re-clocking or jitter reduction, these corrective measures greatly interfere with the critical time domain requirements of the signal.

Music is a time continuum from start to end which when broken is irreparably damaged. No amount of clever manipulation can restore it to its original time / frequency / amplitude duration or relationship, regardless of what the theorists may tell you."

I agree with this philosophy. However, the problem with making it true across the board is one of economy. You can't just take the analog signal directly off of a D/A chip and hand it over to an op amp through a I/V resistor and be ahead of the game. Well I suppose you can, and some manufacturers actually do,,,, but that will probably sound bright, aggressive, and/or fatiguing in the long run. The power supplies, the I/V technique, the analog filtering, and the quality level of all of the supporting parts will make or break the whole thing.

I think if you are not willing to spend too much money on a NOS DAC then you should probably buy a regular "corrective" type of DAC.

[bixby]

Nah, I've heard plenty of TDA 1543 based DAC's (single, stacked, etc) that are not so great.  The Cosine was a premium DAC costing like $3500 (10 year ago money) utilizing simple I/V stage with tube output, Magnequest transformers for choke, output, etc.  These are probably the reason it sounds so good to you frankly.  I wish more manufacturers would take this kind of approach with SOTA chipsets like Sabre instead of sticking a bunch of op-amps after the DAC chip.   

Jon is right, it's not all about the chip.  My ack dac was fatiguing as all get out.

[Folsom]

Well, like I said it's power.

Clean power removes all the fatigue. I've found NOS DACs are the easiest to listen to of all DACs, with good power. 

[jarcher]

I sort of doubt that NOS or NON-NOS or even the DAC chip used is the single most paramount factor in defining the sound quality, for better or worse, of a DAC unit.  The implementation of that chip with all that supports it before and after is just as important if not more so when it comes to defining the success of the sound. quality.  And if old NOS DACs / CD players etc for whatever reason sound subjectively better, I suspect it's because the darker rolled off sound help to mask some of the worst of brittleness that digital playback can produce. 

Which is all not to saw that NOS DACs are inferior, but I would pay more mind to what has been done as far as implementation before and after it, in particular with respect to power supply (which digital seems to be very sensitive to) and input quality, which seems to be well addressed these days w/ respect to timing and jitter thanks to company's like Wavelength. 

The Auralic Vega DAC which Scotty mentions, which is based on a Sabre ESS 9018 DAC, which over & up samples more than just about any other DAC I've seen, even though it is very revealing and not warm, succeeds I think because it takes a SOTA approach to input, clocking, up sampling, output stage and power supply all outside and independent of the DAC chip.  The results therefore I think would be successful even if the Sabre chip were replaced with a NOS one.

[*Scotty*]

Now this is information I read in a 6moons.com review online, and supposedly the ESS 9018 internal up-sampling capability is not used which one of reasons it performs the way it does. http://www.6moons.com/audioreviews/auralic5/1.html
To date I have not liked the resulting sound produced when an ESS Sabre DAC is allowed to internally up-sample the data.
Scotty

[Canada Rob]

Most DAC's sound terrible without good power. Battery operations make them very smooth, but don't have the sparkle some like, found with AC. The cheaper the DAC the cheaper the power supply delivery to the actual chip. Then output capacitors are important too. There's almost nothing between the chip itself and your other equipment. Depending on the unit it isn't often more than two capacitors, some tracings, and your IC's. Which means all the stuff before the chip defines the difference between the $20 1543 and the $3500+ 1543. It's a fair amount of parts, doing different things. It's amazing how many different variations there happens to be. I'm still a huge fan, and wish I could get one of Peter Daniels in the ultimate formation, USB input. Maybe one day I'll just build it by hand.

It's ok though, I just listen to vinyl...

For over five years I've used one of Peter Daniels USB NOS DACs.  He built it specifically for me with upgraded parts.  To this day, it still gives me goosebumps when I listen to it.  I just can't top it when playing 16/44, and it takes a really good vinyl rig to improve upon it.  Audio Zone still sells their version of it and it is also extremely good.  Even though they don't mention it on their website, it can be ordered with USB input.

The problem with many of the "high rez" DACs of today is they give 16/44 the short shrift and put all their eggs into the 24/96 and up basket.  I've been auditioning the Resonessence Labs Herus+ and Concero HD and I am liking what I'm hearing whether playing native 16/44, 16/44 hardware upsampled( which in the past I have hated), or native 24/96.  I've not tried the higher resolutions they are capable of yet.  They designed both the Sabre chip and the DAC, so if anyone should be able to utilize that chip correctly, it should be them.

[*Scotty*]

I think it is possible that in a great number cases the DACs in question are just not very good and only when they are fed a diet of Hi-Rez data does their performace become acceptable. Recalling Sturgeon's Law, 90 percent of everything is crap.
Scotty