Preamps built Into DACs


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A lot of higher end preamps are also DACs. A lot of guys that buy these high end DACs already have a high-end preamp.

How much money could be saved on a $6k preamp/DAC if the preamp section was removed? In my case, a preamp on a DAC is redundant. I believe the preamp section should be an option on a DAC.

What say you?
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There are DACs and there are combo pre-amp/DACs.

One buys what one needs.

Not sure I see a problem there?
In that price range? Not much.
In English language bunch of different words, expressions may mean the same thing and yet the same word can have a tons of different meanings. These factors you should know in order to stay within our 3d without going beyond.

DAC with volume control

Preamp with digital input(s)

Full function preamp(usually applied to the ones with phono)

DAC-preamp

preamp-DAC

...will basically mean the same and share the same idea

Conserning your second paragraph, I believe you're tripping or indeed found yourself in multi-d space and have no idea how to get outahere. Saving money by removing DAC? or preamp? How about removing DAC from CD-player? I don't getitatall. I've always believed that one box will be cheaper that two boxes.
One preamp with DAC and phono will keep you from necessity buying both of separates...

I used to study the multi-d math, but kinda quit doin' that coz got tired understanding those theorems that are necessary for you not to get lost.
To continue studying multi-dimentional calculus I would probably have to smoke an ounce of MaryJohana per week.
Mitch - Beware replacing a good active pre with a volume control in a DAC. Most of them are substandard and will be a step down.

On the other hand, a few are excellent and will probably beat your active pre. Depends on the technology and implementation. It varies widely. I would read the reviews. If they say it beats good preamps, then its probably a good candidate.

Some are based on variable gain control of an active buffer stage. Others are based on resistive attenuation combined with a gain stage. Some are based on using an integrated chip to digitally control the gain of an analog stage. Two of them are based on controlling the reference voltage to the D/A conversion.

The last 2 generally deliver the best SQ, but again it depends on the implementation, the design details. Controlling the D/A reference voltage is the only one that actually reduces distortion as the volume is decreased.

You can also use purely digital volume control, but I dont recommend it. More than about 9 dB of attenuation will start to reduce sound quality.

Another option is to use a passive transformer based volume control (TVC). You basically cannot lose doing it this way and it beats pretty much all active preamps.

Steve N.
Empirical Audio
This is a good question, the ps audio perfectwave dac mk2 has a preamp section in it, wondering how good it could be
Grace M903, Mytek 192 DAC-preamp, Antelope Zodiac+, Lynx HiLo modern professional DAC-preamps have superior preamp section within the price of $2000.
In general, my only concern about a DAC and pre-amp in a single box would be how well is the pre-amp section shielded from RFI generated by the digital circuits/DAC? In general, I would prefer these in separate boxes separated by space as an insurance policy at a minimum. I would definitley not try to cram a low level phono section in there as well.....

A similar concern with integrated amps is proximity of power amp with transformers, etc. to the pre-amp section, again especially with phono. HEre the issue is more EMI than RFI perhaps, but I would prefer separates here as well to physically separate the two as an insurance policy at minimum. Often, noise levels in circuits can affect the sound quality in subtle ways well before any effects are clearly audible.
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Thanks Steve, the reason that I started this thread is that some of the DACs that I'm interested in that have great reviews are DAC/pre units.

I'm a die-hard Audio Research tube preamp guy. I love their sound and I won't entertain any discussion about replacing it with a preamp from a DAC.

Offerings from Antelope Audio and Empirical Audio have well regarded DACs, but they also include a preamp. I can't help but wonder what my savings would be if there were no preamp attached to those units.
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I" can't help but wonder what my savings would be if there were no preamp attached to those units."

It's not about saving money. Its about removing a serious number of veils. Nothing quite like it.

I used a highly modified Levinson pre for years. Mostly wired with silver wire, point-to-point and lots of Black Gates etc.. Nothing like the stock ML. I though it was really transparent, until I developed a DAC volume control. The pre has been gathering dust for years now. Not even close.

The only thing I have found that approaches the tranparency and air of this is a good transformer linestage, such as the Music First. I actually use a transformer buffer now, using the Finemet transformer technology from Feastrex. Even better.

The only requirement for a transformer linestage is that the output drive on the DAC be sufficient. Op-Amp outputs can stay at home.

Steve N.
Empirical Audio
There do seem to be certain components that manufactrurers love to combine and DAC Preamps is one of them. I am no EE and don't understand the allure but you do see a lot of them. Amp builders I have spoken to seem to get a charge (no pun intended) out of building preamps. The reason remains somewhat unclear but to the ones I spoke with it was the challenge of the circuit. I somehow doubt that is why, I think it more an economical one and we need a frank discussion of that.
Audio-Gd has several, this is his starting price point ($549 no remote, $599 with) they go up to about $1900

http://www.audio-gd.com/Pro/Headphoneamp/NFB-10.1/NFB10.1EN.htm
Tim
Preamps, great active preamps, are a must for me. Without it music is
simply not as musical to me. So preamp builders please build on! To my
ears a proper stereo system needs a great active tubed preamp.

To me, I would be wasting money on my system not having my active tube
preamp. So yes, stop putting a volume knob on all those DAC's so when I
buy one I'm not wasting money on that volume knob.

To each his/her own and this is just my experience and preference. Listen
on!
Many have ditched very expensive preamps for a well implemented volume control in the DAC(including me). Considering the amount of loss incurred in an analog cable and running signal through additional circuits I am not surprised.

To me there are no sacred cows in where to put the volume control (which is what we are really talking about here). I used tube pre, solid state pre and now the volume control in the DAC. Then there is the whole debate about analog VC and digital VC in the DAC.

I think the ideal VC implementation would be a DAC with a switch for 0db, -10db, -20db, -30db, -40db attenuation in the analog domain to match DAC output level with speaker sensitivity and desired volume level for the listening session, and then a digital remote control to attenuate up to an additional -20db. Wonder why no one has build this.
If you have just digital sources there is probably no good technical reason to have a pre-amp. I'm sure there are very good dac with volume controls out there. Maybe to introduce tubes in the pre-amp if a tube sound only fan.
Only good reason is sound! Not any other reason.
Generally speaking in audio systems I prefer simplicity as less is often more. But this preference while good in theory(fewer boxes,power cables,IC etc.)takes a back seat to sound quality-music reproduction. We all will have different outcomes and opinions, no surprises there.

Grannyring my experiences mirrors yours, the better quality active linestages(premium tube models in my case) just sound much better, more complete and realistic to my ears. Those who find DACs with intergrated VC to their liking, congratulations and continued good listening.They just don`t cut it for me.
Regards to all.
I tried both ways with my Nuforce DAC-9 192k and preferred the sound with my preamp in place. When I used the DAC as the preamp it sounded a tad clinical and in your face. For my preamp, I'm using a Placette active and it has an excellent volume control. Using the preamp sounded smoother.
Threads like this make me laugh.

Even if you choose to go "no preamp"... there is still a preamp involved!! It's just a lower quality preamp, tagged onto the digital circuitry, sharing the same power supply as the digital section. No thanks!

Do you really think that if you put the circuitry in the same box as the transport/DAC that somehow it magically eliminates preamp circuitry?? Nope.
"The reason remains somewhat unclear but to the ones I spoke with it was the challenge of the circuit. I somehow doubt that is why, I think it more an economical one and we need a frank discussion of that."

I can speak to why I did it in my DAC. It was strictly because there was an opportunity to leverage the D/A technology to create a superior volume control with lower noise, distortion and no compression. It's all about performance. My volume technology can only be done within a D/A converter and cannot be adapted for analog circuits. If it was inferior to other active analog volume technologies, I would not have done it.

I believe other manufacturers typically add inferior volume control circuits because their competition adds this feature, so they have to add this feature. Their marketing depts decide for them. This all got started by one DAC manufacturer IMO.

Steve N.
Empirical Audio
"Wonder why no one has build this"

Empirical Audio and Weiss both have it, at least variations.

Steve N.
Empirical Audio
All good tube active preamps probably do improve the behavior of the amps, particularly dynamics, because they have sufficient drive compared to resistive passive linestages or op-amp DAC outputs.

However, and this is a big however, removing them from the signal chain is even better.

What you must understand is that some DAC volume control technologies do not "replace" the active preamp, they actually eliminated it. There is actually no preamp circuitry in the signal path at all. It is exactly like connecting the line-out of a DAC directly to the amps.

When you do this, the distortion, noise and compression that is in every active preamp, even the most expensive, is eliminated. Sound quality is a LOT better IME, particularly when the drive of the DAC is sufficient, like the drive (current) of an active pre.

Steve N.
Empirical Audio
SteveN,
I``m not an engineer or electronics component builder and thus lack the background to debate at all on technical grounds.
All I have to offer is based on hearing and I trust my ears and my spontaneous reaction to what I hear or emotional response (does it involve me or not and to what degree)What ever steps it takes to get there I`ll do it.

So far in my listening experiences premium quality tube preamps are an asset and clearly improve the sound quality. I`m sure the actual builders/designers of top level preamps could explain why their products improve performance and articulate the reasons(technically) quite well(which I`m unqualified to do ).

There`re just going to be proponents of both sides,direct connection vs active preamps,it`s great to have choices in the marketplace.
Regards,
Charles1dad, you said it very well and my experience is the same. No active preamp in a system is wonderful sounding to some, but I have always found the resulting sound cleaner, lighter and lacking in body, weight, natural tone and impact. No active preamp systems seem to provide more detail and can certainly be quieter, but over time I became aware that the perceived transparency and detail was really a result of other important musical cues being missing.
Hk_fan, in the case of digital domain volume control this is certainly not the case - you do in fact eliminate the "preamp circuitry" entirely. I don't know precisely how Empirical Audio's and Weiss volume control work, but I suspect they also eliminate circuitry and implement VC through a fundamentally different architecture.
So I ditched a $10K 2 box preamp (Modwright 36.5 LS/PS) in favor of a digital volume control, simple because taking it out sounded better to me.

Here is another consideration. Price / performance. Let's say you have a 4K DAC with a build in volume control, and you have $10K in the kitty for an upgrade. You can either buy a $10K preamp and put it behind your DAC (throw in some money for cabling too), or you can buy a $14K new DAC with volume control. In my experience the SQ improvement per $ of the DAC upgrade will be substantially higher than getting the preamp.

Again, I am talking from experience not theory. I recently spend $10K on upgrading my DAC and have fiddled with various preamps in the $5 - $10K range, and there is no comparison. Unless you have analog sources, preamps are dead end technology, and will eventually be replaced by the VC build into DACs. These DACs will also serve as the digital switching hubs. Some are integrating music servers, some will have digital room correction, cross-overs etc.
I think it comes down to the type of sound one likes. Both are ways to build a system and they yield different results - sound of music. As the post above states our actual experiences differ because we all like and are pleased by different sounding systems.
Digital volume controls are much more troubling in my mind, as the only way to reduce volume is to start discarding data.
Edorr,
You have found a solution that works best for you and that`s a good thing.I`ll assume we are all basing our choices on 'actual' listening experinces.I don`t believe top quality preamps are "dead end technology" or will ever be,in fact they seem to be improving.

As long as there`re listeners who hear and appreciate the superior sound quality these preamps offer there will exist a market for them(this won`t include you obviously).
Grannyring summed up the sonic differences very well, I imagine we have similar hearing and listening priorities.Edorr, there`re certainly others who hear things as you also.

For those who say the improved body,tone and dynamics is a coloration, well all I know is this is much closer to what I always hear with live performances(for what ever the reason may be). Edorr you may find your approach is closer to what you hear live as well. At the end of the day we all choose what we feel sounds most right.The lean,clean,thinner sound(less tone and body) is far less realistic and convincing for me.I`ve made my choice.

Edorr, one look at our respective systems would make it clear we have certainly taken different paths to find our individual sonic bliss.
Best Regards,
It makes a lot of sense to bundle preamp and dac these days much like pre-amp and phono pre-amp have been bundled into some pre-amps for years. The fact is digital is the norm now, not phono. So it is a natural thing to do. May not be the best/right solution for all. THat is why there are still separates for purists who care, like me.

True digital integrated amps, like the NAD M2 (all integrated amp functions performed in digital mode except final conversion to analog to drive speakers, though that would likely be done Class D style as well) are the next logical step in the evolution of audio technology and will become more common over time. I would love to try one today and strongly believe this is where things will tend to go over time, and it will all be for the better soundwise as well....

Hey I know that is heresy to a lot of old time analog lovers like myself, but why resist progress? After all , we all love our HD TVS, right? No reason all digital audio cannot be as satisfying, even today. Its the wave of the future. BEst to ride it rather than resist it.
Charles, you are making the incorrect assumption that my current preference to take the (tube) preamp out of the chain is motivated by different preferance in sound (i.e. clean versus full bodied). I thinkg we both strive to recreate the experience of the live event - this has always been my reference.

I have been using tubes and preamps all my life (I have owned Cary 300B, Graaf OTL, Rogue preamp, Audiologic Tube DAC, Modwright preamp). I did not all of a sudden change my preference from "body, tone and dynamics", to a "clean" digital sound. For years, I made the same choice as you.

It just so happens, my current system (with digital volume control), give me a more body, tone and dynamics than anyting I have ever owned, tubes included. We have the same destination, but just get there with different technology.

I am not saying if you took out your tube pre and started using the PWD volume control the same would happen in your system. It is all system dependent.

But again, our music reproduction objectives are precisely the same.
"It just so happens, my current system (with digital volume control), give me a more body, tone and dynamics than anyting I have ever owned, tubes included. We have the same destination, but just get there with different technology. "

Myself, I would like to, and at this point feel pretty confident that I could, drop my tube pre-amp for a good SS replacement and still get the body, tone dynamics etc. I want. The reason would be to not have to deal with tube maintenance and replacement periodically, which is not cheap to do right. I have dabbled with tube and SS DAC (and pre-amp) options to date for example and that experience builds my confidence that either technology can work best. The devil is always in the details, which device specifically, how well does it mesh with the rest of the gear, etc.
"So far in my listening experiences premium quality tube preamps are an asset and clearly improve the sound quality."

I agree. For MOST systems, the tube pre is an improvement. However for well-designed DACs with volume controls, even these will be crushed. There are only a couple out there that accomplish this BTW, so it is likely that you have not heard them.

Steve N.
Empirical Audio
"Even if you choose to go "no preamp"... there is still a preamp involved!! It's just a lower quality preamp, tagged onto the digital circuitry, sharing the same power supply as the digital section. No thanks!"

This is where you are dead wrong. You evidently missed some of my posts. There is actually "no preamp".

Steve N.
"It makes a lot of sense to bundle preamp and dac these days much like pre-amp and phono pre-amp have been bundled into some pre-amps for years. The fact is digital is the norm now, not phono. So it is a natural thing to do. May not be the best/right solution for all. THat is why there are still separates for purists who care, like me."

The distinction that needs to me made is between the DACs that just add a simple volume control in order to add the feature, and others that actually improve upon existing volume control technologies by using the infrastructure only available in a DAC.

Like so many preamps, active and passive, the devil is in the details.

Steve N.
Empirical Audio
Here is one way of looking at it. All the available musical information is encoded in the digital signal. This includes all the timbre, body, spacial information, decay and what have you.

The DAC converts this digital information to an analog signal. Anything added to the analog signal after it leaves the DAC is by definition information that was not originally there.

In many instances what is added may make the sound more pleasing. It may compensate for something your DAC did not retrieve, or your speakers or amps do not reproduce naturally.

The better your system is capable of reproducing the sound encoded in the original digital signal, the less it will benefit from adding something in the chain that adds coloration. In a (hypothetical) "perfect" system a volume control that just controls volume will sound best.

A perfect source (say a live acoustic piano recital) will sound better live than running the same hypothetical perfect source signal into an (imperfect) preamp into hypothetical perfect (i.e. capable of perfect reproduction of the source signal) amps and speakers. QED
" All the available musical information is encoded in the digital signal. This includes all the timbre, body, spacial information, decay and what have you. "

I agree with this and part of why I think the potential for pure digital amps is huge even with audiophiles and that these will be the norm in 5-10 years perhaps.
"However for well-designed DACs with volume controls, even these will be crushed. There are only a couple out there that accomplish this BTW, so it is likely that you have not heard them."

Steve, please list or reference if you have already.

Thanks.
Keep in mind the VC is only part of the design. You never listen to just the VC. There are very good DACs with analog, digital and hybrid VCs. It is conceivable a very good dac that has a digital VC could be improved upon by making it hybrid or analog, but at the end of the day you are buying a DAC/VC package and system performance matters. Also keep in mind some DACs are now 64 bit, theoretically making it possible to control volume in the entire range digitally without any loss.

Some examples:
Hybrid: Weiss (and probably Steve's Overdrive)
Analog: Aesthetix, MSB, Theta
Digital: Bel Canto, PS audio, Berkeley, DCS
Mapman - there are only two DACs that I know of that use the reference voltage to control volume (which actually connects the DAC line-out directly to the amps):

Empirical Audio Overdrive SE

I believe the other is a dCS DAC that is out of production

Steve N.
Empirical Audio
Steve, DCS latest gear has an all digital VC. Why would they have moved to all digital if they had a better mousetrap before? Given that their latest "stack" sells for over $100K I can harldy imagine they did this to save cost.

I have a hunch the latest digital technology allows for the design of a digital VC without any loss of resolution, while avoiding the signal degradation of doing anything in the analog domain. There is a guy in France that build the 64 bit TotalDac, that tried every VC implementation under the sun and settled for a digital VC. The 20K light harmonic Da Vinci is also a 64 bit all digital VC.
Mrvco in what price range??
They are equally troubling in my mind, and for this reason I have been avoiding them like the plague. However, my ears are telling me otherwise now, and the fact that a number of >$20 DACs use them suggest they can't be all that bad. It is conceivable an well implemented analog VC will elevate performance of such ultra expensive DACs even higher.
Hi Edorr,
I get your point, of the examples you list I`ve heard theWeiss, MSB(diamond stack and fremto clock) and the DCS in direct mode to an amplifier. They just did`nt get it done for me. That`s why I `m not saying you`re wrong but you know what,we just likely hear things differently.

The different make up of our systems is a reflection of how we hear and are drawn to. Not better vs worse just different perspectives.
I don`t feel an aligiance to tube preamps and thus unwilling to embrace the new,not at all.New does`nt always equal improved or better, sometimes it`s just new.

If I ever hear a DAC/VC combination that sounds better I`ll readily admit it, all I want is pure, natural sound and realism in my system.Which ever technology does it best to my ears then that`s the direction I`ll follow.If I find a DAC/VC unit that provides the realistic organic tonality,body and 'breath of life-vitality' that I have with my current preamp I`d gladly jump ship.It has`nt happened so far.
Regards,
Charles. Fair enough. With the lineup of DACs your listing I can't say you have been skimping on hardware. You got me tempted to try to insert a preamp and give it another try.

Thankfully I don't have any rackspace :) left. Do you still own the Coincident preamp?
Hi Edorr,
You`re very satisfied with your current setup, you may not need a preamp for your needs.
I `ve own my Coincident linestage and their 300b SET amplifier for over 3 years. I plan to keep both for many years to come.The funny thing is my genuine admiration for both 'continues' to increase. I`m fortunate(lucky?) as they`ve led me to pure emotional involvement and musical bliss.
Best Regards,
"Steve, DCS latest gear has an all digital VC. Why would they have moved to all digital if they had a better mousetrap before?"

I believe it was probably abandoned because it is very difficult to implement. It puts another layer of complexity and linearity concerns on top of the architecture.

It has some limitations, such as no ability to go to zero volume. It can go really low, but not zero typically. I dont see this as an issue.

Steve N.
Empirical Audio
"However, my ears are telling me otherwise now, and the fact that a number of >$20 DACs use them suggest they can't be all that bad."

Well even the best S/W DSP volume controls seem to cause audible artifacts at more than about -9dB of volume reduction. No amount of dithering and resampling will help IMO.

The besst overall solution is to use a good volume system to reduce the volume to listening levels and then adjust finely for each track using -0 to -9dB of digital volume. Works like a champ.

Steve N.
Empirical Audio
.... I believe it was probably abandoned because it is very difficult to implement. It puts another layer of complexity and linearity concerns on top of the architecture....

The worlds #1 manufacturer of cost no object DACs just released a >$100K DAC, but they abandoned the optimal implementation of the VC they used in earlier models and reverted an approach that compromises sound quality because doing it right is "very difficult to implement". Not a very plausible explaination
.....Well even the best S/W DSP volume controls seem to cause audible artifacts at more than about -9dB of volume reduction. No amount of dithering and resampling will help IMO....

There is absoltely no consensus on this, nor confirmation in listening tests. Lots of digital guru's will tell you -25db is fine. My personal experience confirms this.

....The besst overall solution is to use a good volume system to reduce the volume to listening levels and then adjust finely for each track using -0 to -9dB of digital volume. Works like a champ....

In principle this seems like a very good approach. I personally would think a 0db, -10db, -20db -30db -40db analog domain attenuation switch and an additional 25db to work with in digital domain during operations would work just as well, but we're splitting hairs.
I note the following from the manual of my Wadia 121, which uses digital VC:

"Best performance is obtained when operating the Wadia 121Decoding Computer Volume Control near the top of its range. If needed, the maximum output level of your Wadia 121Decoding Computer can be adjusted to match the overall sensitivity of your system so that critical listening will take place with the volume control operating near the top of its range. Critical listening should be done when the 4th or higher LED is lit. The maximum out level of the Wadia 121Decoding Computer is adjustable by means of a series of IR commands issued from the Wadia remote control. The Wadia 121Decoding Computer output level is factory set to accommodate the most common range of system sensitivity. If you find that your typical volume level during critical listening is below the 3rd LED on the LED display, it will be advantageous to use a different setting."

The output levels can be adjusted to 4.0v, 2.0v, and1.0v.

This seems to support Steve's statement that "even the best S/W DSP volume controls seem to cause audible artifacts at more than about -9dB of volume reduction." I wonder how he feels about Wadia's approach to allow the user to adjust the output voltage. Since my understanding of electronics is so poor, I won't pretend I understand all of this.