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. |
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 |
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. |
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. |
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 |
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. |
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. |
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? |
.... 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 |
Agree. Only works with the same observer listening on two different systems. Even then I think the experiment is flawed because you could have a system that simply is more clear in the frequency range of human voice, which could be happen with boor bass response. for example on a set of electrostats with poor low frequency response this may be easier than on a true full range system.
Nonetheless, just for kicks, I'd be happy to try. If you set up a file transfer (you have my email), I'll give it a shot. Keep in mind I am not a native English speaker though! |
.....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. |
Seems like an excellent approach. However, I believe going from 4.0v to 1.0v represents about 15db attenuation. Most listening takes place in the -20db -40db attenuation range (if you have sensitive speakers could go all thw way up to -60db), so the Wadia would still have to apply at least -25db attenuation in the digital domain, far more than -9db. It seems like the adjustment to output level are to adjust for speakers sensitive during initial setup. These sensitivies have indeed a range of about 15db. The for day to day listening you do digital domain volume control in the -30db - 0db attenuation range. |
Tru. I don't think all digital VC are created equal, and if someone sells a 100K dac with digital VC, they probably cracked the code on how to do it without losing reslution (or the minimal loss ofsets the loss incurred with analog VC). I mentioned the 64 bit megabucks Da Vinci and Totaldac, that also do digital VC.
This is important to me because I own the EMM Labs DAC2X, which currently has not VC, but its architecture allows for implementing digital VC through firmware. I am hopefull Ed Meitner joins the ranks of the digital VC done right crowd and delivers a stellar digital VC.
I am currently using the digital VC in my Trinnov processor, and according to the manufacturer at 50db attenutation I am losing information. Of course, this has not stopped them for using the exact same digital VC in the $40K ADA Reference SSP, so it can't be all that bad. |
Agree again. At the end of the day, all designs involve compromise. I don't really care if a VC is digital, analog, or hybrid, but just how it sounds. It stands to reason that with the advances in digital technology the gap has narrowed, and DCS digital VC in their 100K DAC suggest when you pull out all the stops, a digital VC can be superior or equivalent to the best that can be achieved analog. This is encouraging because digital technology tends to trickle down very fast. But again, the proof is in the hearing. FWIW, in the Stereophile review, out of the DCS debussy, Weiss 202 and Bel Canto 3.5, the reviewer preferred Bel Canto, which has Digital VC (the Weiss has not). The reviewer never even mentioned it - just reported what he was hearing. |
The chief designer at Bel Canto send me a one pager explaining the merits of digital volume control, and how unless you have very high sensitivity speakers (horns) and needs very high attenuation, there is absolutely no loss in a digital VC. If their VC was analog he would not be passing out such information. |
Steve, you may have better ears than me (very possible), but I doubt your system is more resolving. I use your offramp 5 with monolith, the EMM labs DAC2X (used in professional studios) and the same speakers the guy that does HD remastering for HD tracks uses in his studio. |
Steve, how would that work? You could get me a "live in the bluenote recording" and see if I can hear what table three was ordering on track 5 at 3 minutes 12 seconds into the track (two dry martinis)? Would be interesting, but not methdologically sound, because it does not account for difference in sensitivity of the hearing of the observer. One of us may simply have better hearing. |
