Best alternative: Preamp with built in DAC chip or Modern DAC

[edorr]

Most DAC's are DAC's inserted into preamps. They just don't have analog inputs. What do you suppose is different?

Not sure about the NADAC, but most DACs do volume control in the digital domain, which is of course an entirely different approach / architecture than the analog domain volume control of a preamp.

 

[spazmatron]

Thank you for that clarification, Blizzard. I understand things a bit better now. I never really thought the NADAC could be completely transparent, but by inference, you have just confirmed that it is not. I am still interested in hearing it, though, and look forward to visiting MadFloyd. Perhaps we will bypass the Pass preamp for comparison.

I have not daisy chained 2 preamps mainly because I could never see myself spending the extra cost, so it never really occurred to me to try. Might be fun just to see how much the sound degrades. As Tim, wrote, the question is, "Is it audible?" I can't say until I've tried it.

The questions in my original post are being answered and I have learned something from having started this thread which was not clear from the other two discussions on this topic in the other threads. So I appreciate your input and that from others.

For the sake of my sanity when you pop round to madfloyds please definitely try the dac direct and with pre then compare.

Bring your thoughts Back here as I will be most interested.

 

[Blizzard]

For the sake of my sanity when you pop round to madfloyds please definitely try the dac direct and with pre then compare.

Bring your thoughts Back here as I will be most interested.

And make sure to try without HQplayer adding the fairy dust when the Pass is connected as well. As this is how 98% of users experience the NADAC when connected through a preamp.

 

[Blizzard]

Not sure about the NADAC, but most DACs do volume control in the digital domain, which is of course an entirely different approach / architecture than the analog domain volume control of a preamp.

They do these days much more than in the past. This is because there's an incredible volume control built right into the DAC chips anyways. And for most chips, this volume control can't be bypassed. So why not take advantage of it and utilize it? After all that's why it's there. But of course, it's not much of a money maker enabling this feature, and it comes free with the package. So some try to come up with creative ways to add expense to their products. The standard mark up is BOM x 6. So by adding to the BOM, you are adding to the net profit as well.

Also the DAC must have a low noise floor, so for anything with tubes, this volume control is out of the question. Because only the music is turned down, but the noise level doesn't change. If used with tube gear, at low level listening the hiss, would drown out the audio. Analog volume controls turn down the hiss as well. Traditional class A stuff also has a high noise floor.

 

[edorr]

They do these days much more than in the past. This is because there's an incredible volume control built right into the DAC chips anyways. And for most chips, this volume control can't be bypassed. So why not take advantage of it and utilize it? After all that's why it's there. But of course, it's not much of a money maker enabling this feature, and it comes free with the package. So some try to come up with creative ways to add expense to their products. The standard mark up is BOM x 6. So by adding to the BOM, you are adding to the net profit as well.

Also the DAC must have a low noise floor, so for anything with tubes, this volume control is out of the question. Because only the music is turned down, but the noise level doesn't change. If used with tube gear, at low level listening the hiss, would drown out the audio. Analog volume controls turn down the hiss as well.

Right. but to say "Most DAC's are DAC's inserted into preamps." is not necessarily correct, because DACs have a fundamentally different volume control architecture than preamps.

 

[Blizzard]

Right. but to say "Most DAC's are DAC's inserted into preamps." is not necessarily correct, because DACs have a fundamentally different volume control architecture than preamps.

It all depends on the DAC. You can use the exact same volume control in a DAC, as a preamp.

 

[PeterA]

No he can't explain it in electronic engineering terms, that's why he said fairy dust. Replace that word with magic. It's the same thing, you love the magic of Your pass gear. Cool.

These are lazy terms to explain something which is not clearly understood by the user of the term. If something specific were added to a circuit to create distortion or emphasis a certain harmonic or frequency and the result was a warmer, richer, leaner or strident sound, that I can understand. It would be more precise and less lazy. It would also be more helpful in a thread like this.

Yes, I like the sound of my system specifically for particular engineering decisions that the designers made, none of which involve magic or love. Emotional connection, perhaps, but that is a response to the results, not an explanation of why something sounds the way it does. The term "natural" comes to mind to describe the overall sound, but that term is also controversial in these pages, as we have learned.

"Cool", is kind of funny. I often wish it were the case. I think of Pass amps as kind of warm, to the touch, that is, rather than warm sounding.

 

[TBone]

Everything adds some degree of coloration. even a 1' length of speaker cable

It's the degree of coloration I'm concerned about ... consider the poor ole tiny cart output signal before it arrives at the phono-stage, never mind the pre-amp..

removable head-shell [cart clip/solder/wire/solder/pin]
tonearm [pin/solder/wire/solder/pin]
cable [pin/solder/wire/solder/rca]

and consider the importance/quality of the shielding, wires, solder, pins, rca's, etc etc ... makes you wonder how we can hear anything at all

 

[edorr]

It all depends on the DAC. You can use the exact same volume control in a DAC, as a preamp.

You can, but in pratice very few DAC builders do, as you just asserted yourself.

 

[Blizzard]

You can, but in pratice very few DAC builders do, as you just asserted yourself.

It's a good thing we are all free to support the manufacturer who chooses to do things right. But the key to being able to determine this is, to know what doing things right is in the first place. Education is your best friend in this department.

 

[edorr]

It's a good thing we are all free to support the manufacturer who chooses to do things right. But the key to being able to determine is, to know what doing things right is in the first place. Education is your best friend in this department.

My ears are my best friend. I used to religiously avoid digital domain volume control (along with many others), but presently happily use the PS Audio digital volumen control with great effect. I also took the SPectral preamp out of the chain, which worked fine with spectral poweramp, but totally destroyed sound quality when inserted between PS Audio DAC and Poweramp. NO substitute for trial and errror in my experience.

 

[Blizzard]

My ears are my best friend. I used to religiously avoid digital domain volume control (along with many others), but presently happily use the PS Audio digital volumen control with great effect. I also took the SPectral preamp out of the chain, which worked fine with spectral poweramp, but totally destroyed sound quality when inserted between PS Audio DAC and Poweramp. NO substitute for trial and errror in my experience.

Yes PS audio DAC's are also designed with a robust gain stage for direct connection to amps.

 

[Blizzard]

Thank you for that clarification, Blizzard. I understand things a bit better now. I never really thought the NADAC could be completely transparent, but by inference, you have just confirmed that it is not. I am still interested in hearing it, though, and look forward to visiting MadFloyd. Perhaps we will bypass the Pass preamp for comparison.

Of course the NADAC won't be completely transparent. But the most transparent way you will ever hear it is by connecting it straight to the power amps. If you think it sounds worse, that only means you like the coloration's introduced by the interconnects and the preamp. It won't be due to any impedance mis-match or lack of voltage.

 

[Purite Audio]

I've posted this several times already, but fell on deaf ears to some. But you really need to listen to what he's actually saying, because he's a very clever man, and knows the myths surrounding analog volume controls. So he presented things in a way that the naysayer would have trouble arguing with. IE, "Analog volume controls are better", but this is only if they have a noise floor below -135db. Good luck with that But then you also have other artifacts with analog volume controls as well like the extra circuity in the signal path, so it's pretty much ridiculous if you think you can do a better analog volume control in a DAC with a Sabre chip, than the digital one in the chip. However, the DAC must have a very low noise floor for this to be true. Great example, the NADAC.

There is absolutely nothing the matter with a properly engineered digital attenuator, but, an analogue attenuator turns down signal and noise, digital attenuation only attenuates signal, this is why it is good practise not to use too much digital attenuation.
Weiss use a variable analogue output and to fine tune a properly dithered digital attenuator.
Keith.

 

[Blizzard]

There is absolutely nothing the matter with a properly engineered digital attenuator, but, an analogue attenuator turns down signal and noise, digital attenuation only attenuates signal, this is why it is good practise not to use too much digital attenuation.
Weiss use a variable analogue output and to fine tune a properly dithered digital attenuator.
Keith.

But the issue is null and void if the noise floor of the DAC is so low that it's completely inaudible to the human ear.

 

[Purite Audio]

But the issue is null and void if the noise floor of the DAC is so low that it's completely inaudible to the human ear.

Unfortunately the dac isn't the only component in your system that generates noise.
Keith.

 

[Blizzard]

Unfortunately the dac isn't the only component in your system that generates noise.
Keith.

Yes but the DAC comes before everything else. So if noise is added by the amp, the volume control on the preamp/DAC isn't going to attenuate it no matter if it has a digital or analog volume control. And if your source is analog, then you won't be using a digital volume control built into a DAC chip, FPGA, DSP chip etc. Digital volume controls are only for digital sources.

 

[Purite Audio]

Yes but the DAC comes before everything else. So if noise is added by the amp, the volume control on the preamp/DAC isn't going to attenuate it no matter if it has a digital or analog volume control. And if your source is analog, then you won't be using a digital volume control built into a DAC chip, FPGA, DSP chip etc.

No, that is the difference between digital and analogie attenuation, analogue attenuates signal and background noise .
It really isn't an issue Ifyou have a properly dithered digital attenuator and do not attenuate too much, that is why variable analogue outputs such a good idea.

Keith.

 

[edorr]

Yes PS audio DAC's are also designed with a robust gain stage for direct connection to amps.

Paul McGowan nonetheless uses a tube preamp (Aesthetix Calypso) between his DAC and Poweramp, and will be releasing his own PS audio preamp shortly. I actually kept urging him to try one having achieved great results with ARC 5SE, and he finally gave in and changed his position that preamps always degrade sound quality.

 

[Blizzard]

No, that is the difference between digital and analogie attenuation, analogue attenuates signal and background noise .
It really isn't an issue Ifyou have a properly dithered digital attenuator and do not attenuate too much, that is why variable analogue outputs such a good idea.

Keith.

Yes it isn't an issue if you have a 32 bit volume control like is in the sabre chips. The only advantage you would get with the variable analogue output is if the DAC had a high noise floor, or it doesn't have a DAC chip with a 32 bit volume control like the Sabre inside. My chipless DAC for example uses an analogue volume control. But the only reason it does, is because I don't have a DAC chip in there with a 32 bit digital volume control built into it that can't be bypassed.