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. |
".....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."
I have a background implementing dithering and resampling algorithms for image processing applications used by the government and military. Not sure about this statement either. I would expect different yet comparable results in terms of accuracy to the alternative of not using digital if done well. Of course, that's always the big if with anything.
Also, the algorithms needed to accomplish optimal results have been well documented in academia for decades already and are old hat in the image processing world. I have no idea why it need cost a fortune to implement decent software based dithering and resampling to lower volume in home audio gear these days. That's why I like to buy gear that likes to advertise how their gear achieves performance, not just the claimed results. Then one can really know the value of what they buy if they care enough to do the homework.
In the case of DCS, specifically the newer more mega buck than ever Debussy gear, theirs is seemingly some of the most sophisticated home digital audio processing gear and software out there from what I read (with sound quality to match bsed on actual audition) but it comes for a hefty price. I would expect a very good perhaps reference implementation there that noone could fault based on technical approach nor listening. |
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. |
"I am currently using the digital VC in my Trinnov processor, and according to the manufacturer at 50db attenutation I am losing information."
Isn't loss of information a gradual thing with any volume control as the signal is attenuated? I don't think it just suddenly happens at some point. Attenuation might occur at different frequencies at slightly different rates for example with an analog control.
However each volume control, analog or digital might attenuate the signal slightly differently at each step, so no two necessarily are created equal. I would expect digital attenuation done right to be as good or perhaps even superior in terms of linearity and presenting what can be presented at any particular volume well.
Again, I suspect that this is another case where digital gets a bad rap categorically for no good reason. There has to be both good and bad digital and analog volume controls. ANy company that cares about good digital sound quality should be able to do it both well and in an affordable manner these days based on available technology. The technical challenge of implementing a good digital volume control algorithm would seem to be trivial compared say to the challenges of managing jitter as needed in real time during playback, IMHO. |
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. |
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After reading all of the above, the high end tube preamp is the way to go for me. In five years as digital technology continues to evolve, I'll revisit the feasibility of using the preamp section of a DAC.
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"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."
I agree this is probably the best strategy in most cases today.
I try to keep the volume control on my Squeezebox Touch controls at max normally, then set my preamp volume to desired volume level for most tracks. Then I use the TOuch VC if needed to lower the volume a touch if needed from there, especially for louder recorded tracks. A bonus with a device like SB Touch is that remotes, computers, tablets, handhelds or any wireless device with a web browser can be used to tweak the volume down on the Touch from anywhere in the house as needed. |
Mapman - Look, I have used a few digital volume controls, including the one in the DEQX, iTunes and Amarra. By far, Amarra is the best sounding volume software so far, and it starts to affect the SQ at more than -9dB. I can hear this because I have on of the most resolving systems on the planet. I clearly hear lyrics in tracks that noone else can make-out.
In most peoples systems they will probably not hear this effect until maybe -20 dB or more. This is due to the fact that there is so much other noise, distortion and compression in the typical system that these effects are masked. This masking can be caused by jitter from the source, active preamps and even poor amplifiers.
Steve N.
Empirical Audio |
"the reviewer preferred Bel Canto, which has Digital VC"
I read this review. I think the digital volume they are talking about is a digitally controlled analog volume chip. I dont believe it is DSP. They also used a certain low-jitter USB to SPDIF converter to drive the DAC BTW.
Steve N.
Empirical Audio |
Steve,
I have no doubt your system is ultra resolving.
Can you tell me what it is, out of curiosity?
Thanks. |
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. |
Mapman - sure, my system comprises:
2009 Mac Mini with SSD and 8Gbytes DRAM (better than newer versions IME). Amarra rev 4318 used for playback - 3 EQs are used in Amarra to flatten the speakers and room. Tuned with calibrated mic Earthworks M30 and iTunes Audiotools. Music Files are all .wav format uncompressed.
16-foot Polestar USB cable
Short-Block USB cable filter
Empirical Audio Overdrive SE DAC - used for volume control and D/A
Empirical balanced "bare-wire" silver cables
Empirical Audio Final Drive transformer buffer for galvanic isolation and achieving true-balanced signals (2 chassis). Also switches in the Home Theater
More Empirical balanced "bare-wire" silver cables
Empirical Audio modded Parasound JC-1 monoblocks - power cables are top of line silver Tekline.com
Empirical Audio Clarity7 speaker cables
Custom 4-foot ribbon speakers with 10" bass-box underneath. Custom crossover with Jensen Capacitors air-core inductors, V-Cap Teflons, non-polar Black Gates and low-inductance planar resistors. All wired with silver-plated copper wire in multiple twisted-pairs.
I also have a Sonos connected with cheap S/PDIF cable to an Empirical Audio Synchro-Mesh reclocker that feeds the S/PDIF input on the Overdrive DAC for more casual listening.
I dont sell the cables anymore BTW.
Steve N. |
Ed - I'm sure your system is resolving. You may have one of the few.
Maybe we should exchange some tracks and find out how resolving.
Steve N.
Empirical Audio |
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. |
Ed - I think this is possible. I have some old tracks that recently I noticed new lyrics and background singers that I never heard before. The challenge will be to distinguish the lyrics and understand them.
Steve N.
Empirical Audio |
Understanding lyrics is a particular type of human skill. Some people are just better at it than others. Seems like an extremely poor way of testing how resolving a system is. |
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! |
