[Rob Watts]

Yes it does attenuate the signal by 2.73 dB - but you can simply increase the volume control to compensate. It won't change the actual clipping point, or the maximum power output.

 

[jlbrach]

without the 3DB attenuation it is already difficult to drive the HP's I mentioned...what volume level is it safe to go to before it will clip?

 

[Rob Watts]

No danger of clipping at all even at +7dB whilst using Blu 2. So clipping is only possible at +8 dB.

 

[jlbrach]

ok great,so i assume that using the dave alone it would clip at +5 and above?

 

[Rob Watts]

Yes - your fine at +4 dB with Dave on its own.

 

[jlbrach]

just to put this subject to bed,is it hard and fast that +5 will clip at all times and to never go beyond +4 on the Dave?

 

[Rob Watts]

No - as a program material that has a peak level at say -1 dBFS will allow +5 dB operation without Dave clipping. But sources that do hit 0 dBFS will clip.

 

[jlbrach]

not entirely sure i understand the terminology but i appreciate the answer

 

[Rob Watts]

not entirely sure i understand the terminology but i appreciate the answer

dB is a relative scale, and it could be set to anything you want. But dBFS means dB full scale and applies to PCM so 0 dBFS is the absolute maximum you can get out of the PCM - so a sine wave at 0dBFS will hit the max positive peak level and (almost) the max negative peak level.

What I am getting at is quiet recordings where the peak output does not hit 0 dBFS (or the max level PCM can do) will not clip even with volume set to above +4dB. Let your ears be the guide you will hear it harden up when starting to clip.

 

[jlbrach]

a quick question regarding the use of external amps....in most all cases when using a loudspeaker system one would routinely use a power amp with the dave or dave/blu 2.....it is pretty much unavoidable when powering a serious floor standing speaker system and nobody questions the transparency of such a setup yet when one speaks of possibly using a headphone amp to listen to hard to drive HP's people speak as if it will degrade the transparency etc and in general downplay the use of such headphone amps...personally i do try to avoid the use of an external amp with my dave and can do so easily when pairing with my Utopia's which as so easy to drive but if one used the LCD-4 or Abyss it is a more difficult decision.....in most cases the dave does drive these HP's well but in some cases with certain recordings which are mastered at very quiet levels it is problematic to listen to the dave alone....for example give Joe henderson "the state of the tenor,live at the village vanguard" a listen...it takes quite a bit of power to listen to it at satisfactory levels......the Blu 2 being 3 DB less would make this more of an issue....I am curious what people think?what people do?what thoughts anyone has?

 

[Whazzzup]

an external music server playing hi res will bump the volume up, or cause you to turn down the volume on your dave. Thus create more headroom. I don't have lcd4 or abyss and use an amp, course I have a bar of soap handy just in case.

 

[JaZZ]

a quick question regarding the use of external amps....in most all cases when using a loudspeaker system one would routinely use a power amp with the dave or dave/blu 2.....it is pretty much unavoidable when powering a serious floor standing speaker system and nobody questions the transparency of such a setup yet when one speaks of possibly using a headphone amp to listen to hard to drive HP's people speak as if it will degrade the transparency etc and in general downplay the use of such headphone amps...personally i do try to avoid the use of an external amp with my dave and can do so easily when pairing with my Utopia's which as so easy to drive but if one used the LCD-4 or Abyss it is a more difficult decision.....in most cases the dave does drive these HP's well but in some cases with certain recordings which are mastered at very quiet levels it is problematic to listen to the dave alone....for example give Joe henderson "the state of the tenor,live at the village vanguard" a listen...it takes quite a bit of power to listen to it at satisfactory levels......the Blu 2 being 3 DB less would make this more of an issue....I am curious what people think?what people do? what thoughts anyone has?

With speakers you can't avoid to use an additional amplification stage – which means the signal will be degraded to some degree. With (most) headphones you can – speaking of Chord DAC/headphone amps –, so adding an amp to the chain will degrade the signal as well, thus make the sound objectively worse than without. That's the whole story.

There's no wire-with-gain amp (although some Head-Fiers call their own amps like this), which can easily be proven with systematic comparative tests and also the fact that all amps sound different. That's why Rob is about to develop his series of «digital class A amps» promising to realize exactly this classic ideal. I hope he will integrate an output for electrostatic earspeakers, but am aware that my wish is a bit utopic.

 

[Muataz]

I think it would be more interesting to have active speakers where each drive unit has a dedicated power pulse array driving it. Each, of course, would have band-limiting filtering for the driver it's powering. Then, "room correction" is a secondary function of these digital amplifiers and there's no stupid passive crossover sucking up ridiculous amounts of power.

Since you're expecting to be able to get 10s of watts of power from a power pulse array in the first iteration and since there's no passive crossover, the resulting speaker should be quite something.

Now, to find a speaker that's amenable? ATC?

Now playing: Stars of the Lid - Dust Breeding (1.316) +

With this possibility, we can build speaker from the best drivers and tune them for 1/10 price of high end speaker that will never be perfect

 

[ciukas]

@Rob Watts I plan on following your lead in having the Davina travel w me everywhere in my carry on so I can have the full power of 1 million taps by my side, except that I'll be doing so w my Hugo 2. Could you please explain how the Hugo 2 can magically output music with all the processing power of 1mil taps? From what I understand, the Davina (or the Blu mk II) handles most of the processing power from the source in real time, feeding all that new upsampled info w no perceptible input lag to another DAC/Amp (Hugo 2/Dave). If that is true, with taps being equal, what then are the differentiating factors in sound quality being played by the Hugo 2 vs the Dave? Are their own tap capabilities being bypassed completely, and are the WTA filters, supercapacitors, and output stage the differentiating factors thereon? For relatively easy to drive iems or headphones such as the Focal Utopia, can one assume that there wouldn't be much of a difference between the Hugo 2 + Davina vs the Dave + Davina?

You also previously mentioned the Davina would be able to upsample and encode ripped cd/vinyls 'offline' to Blu mkII/Davina wav format, storing said files on a DAP feeding a Hugo 2/Dave therefore not needing the Davina as a processing unit in such a chain. How would that upsampling and encoding work? Will Chord provide Davina users with a proprietary app to convert such files? Will the Davina be able to upsample any audio files? How large would such files be?

To more practical matters, how do you store the Dave/Blu mk II in your carry on? Do you have some sort of customized giant foam insert with Dave/Blu mk II cut outs? Also, where do you keep the Dave/Blu mk II when you're out of your hotel room? Locked in the carry on?

 

[Rob Watts]

Lots of questions there.

An M scaler converts 44.1/48 to 705.6/768 with a million tap WTA filter, and with the million taps I can guarantee better than 16 bit accuracy for the re-constituted interpolated samples, as the difference between an ideal sinc filter (which would reproduce it absolutely perfectly) and a M scaler WTA filter is much smaller than 16 bits. Hugo 2 can accept 768 kHz dual BNC as it's input, so it is designed to work with an M scaler.

Dave is still more transparent than Hugo 2 (it's immediately obvious on an AB test), and that is down to a number of reasons. But the biggest factor is the budget for Dave allows for much better analogue components.

As a rule of thumb, you can assume the file size will be 16 times larger. Unfortunately, it has to be in WAV format, as FLAC does not support it. A number of free apps allow editing and creation of audio files - check out Audacity. The file should allow for very efficient compression.

I just wrap Dave and Blu 2 in bubble wrap, then it goes into my carry-on. When traveling, the carry on does not leave my sight!

Rob