[JaZZ]

  Electrostatic direct drive from a single stage pulse array DAC? Funny, John and I were talking about it today. I think he thought I could design one in an afternoon....

 
Yes, please do! Let's say tomorrow afternoon? But I don't want to rush you... Next Monday is o.k., too.
 
Thank you, Rob!

 

[Rob Watts]

   
Hello, what does the extra cores mean?
 

 
A core is a DSP core - it is a FPGA dedicated module that can do multiple adds, accumulation and multiply amongst other features in one module. Sometimes I create my own cores out of FPGA fabric, once I have run out of dedicated FPGA hardware DSP cores. I use cores as the building blocks for large WTA filters. Dave's FPGA has 132 hardware DSP cores, but I needed 166, so I created the missing 34 cores out of FPGA fabric (that means gates and flip-flops on the FPGA).
 
Rob

 

[JaZZ]

Rob, I just hope my previous post didn't come across as respectless – my sense of humor may not quite match with others'.
 
In any event I have already expressed my respect for you and your work. The Hugo was a milestone, and DAVE is a masterpiece in my book. Now if I could enjoy this revolutionary sound quality also with my electrostats! It's not that I generally attribute higher sound quality or realism to them, but it would be great to have equal footing for them.

 

[Rob Watts]

  Rob, I just hope my previous post didn't come across as respectless – my sense of humor may not quite match with others'.
 
In any event I have already expressed my respect for you and your work. The Hugo was a milestone, and DAVE is a masterpiece in my book. Now if I could enjoy this revolutionary sound quality also with my electrostats! It's not that I generally attribute higher sound quality or realism to them, but it would be great to have equal footing for them.

Actually I was thinking Tuesday, would that help?
 
It would be interesting, I guess the biggest headache would be scoping the project out (how much voltage, how much current... plus any other issues). Then making it universal, so lots of things to think about. But being short of interesting things to do I am not short of, so I guess you will have to wait.... till maybe Tuesday 7 Jan 2020.
 
Rob

 

[m0nster]

Has anyone of you tried the MrSpeakers Ether or Ether C on the DAVE? I would be interested to hear if they pair well?

 

[JaZZ]

 

  Rob, I just hope my previous post didn't come across as respectless – my sense of humor may not quite match with others'.
 
In any event I have already expressed my respect for you and your work. The Hugo was a milestone, and DAVE is a masterpiece in my book. Now if I could enjoy this revolutionary sound quality also with my electrostats! It's not that I generally attribute higher sound quality or realism to them, but it would be great to have equal footing for them.

Actually I was thinking Tuesday, would that help?
 
It would be interesting, I guess the biggest headache would be scoping the project out (how much voltage, how much current... plus any other issues). Then making it universal, so lots of things to think about. But being short of interesting things to do I am not short of, so I guess you will have to wait.... till maybe Tuesday 7 Jan 2020.
 
Rob

 
Oohh!!!  

Well, you're the boss. – Sadly my upper limit will be dropped to 11.35 kHz till then.

 

[rgs9200m]

I just have the Hugo TT so maybe this isn't the place to post it, but how does it magically get rid of the shrillness of redbook digital without muddying up the bass (especially the upper bass) that can make things kind of nauseating?
In my experience with CD players from Playback Designs (MPS5) and Burmester, they did address the shrillness and fatigue, but always added some terrible softness.
Curiously, SACD solves this problem most of the time and that's why I love it still. But the Chord way is the best I've heard in keeping impact and transparency without losing focus on regular-resolution non-SACD. And it works on even old digital recordings of popular music.

 

[Mojo ideas]

Hmm, lots of questions today!

Firstly, I have not said that 44.1/16 bit is better than HD PCM (its easily better than DSD IMHO - and this is an important requirement - on my DAC's). Probably the best recordings I have is 192/24 - and generally, all things being equal, higher SR is preferable - but not by much. In principle - and note I mean in an ideal world - 44.1/16 is capable of very much better performance than we currently get - with a large enough tap length, you can recover the timing perfectly, assuming the ADC has zero (and I do mean zero) aliasing which currently the pro ADC's do not have - its as bad as -6dB!. Moreover, properly dithered 16 bit is capable of perfectly resolving an infinitely small signal - if you take an infinite period of time to do the FFT or correlation. So the format is capable of, again in principle, of perfectly reproducing the original timing information and perfectly capable of accurately reproducing very small signals.

But "you know nothing Jon Snow" is my favourite quote,and until you do carefully structured and rigorous listening tests, this quote applies. One of the interesting things about the Davina project is being able to decimate 705.6 k to 44.1 without any aliasing at all. Couple that with a long tap length WTA filter on the DAC, then I can actually hear the losses involved and be able to actively minimise them. The next question is the effect of bit depth, and how to treat truncation without degrading sound-stage depth, and this will also be a very interesting test. Now its very easy to do it for a 16FS signal (as in Dave), you simply use a 350dB noise shaper - but this is not an option at 44.1

On to the noise shaper - the 350 dB limit is technology limited (and its a very complex story), given that I am using 20 elements on the pulse array. I could detect a change going from -330 to -350, but frankly it was small. Any more depth to wring out? Perhaps. But by far the biggest loss is on the analogue power amplifier - the digital power amp will solve it (I know as the early prototype had amazing depth reproduction). Then there is the issue of the ADC itself, and again we have Davina coming to the rescue, as I have already designed the ADC noise shaper and this exceeds 350 dB.

I mentioned tap length, and yes I suspect that longer tap lengths will give better sound. But by how much? Frankly I do not know, and its possible its not much. I have mentioned 1M taps before, as this gets us to a sinc function with an accuracy of better than 16 bits - this then guarantees time domain performance exceeding 16 bits accuracy for a 16FS output signal. Unfortunately, the FPGA's capable of doing this are insanely expensive.... And I shudder at the design time needed to write close to 1,000,000 lines of code and verify the design, let alone getting timing closure on the FPGA....

Electrostatic direct drive from a single stage pulse array DAC? Funny, John and I were talking about it today. I think he thought I could design one in an afternoon....

And talking of Jon Snow - season 6 Game of Thrones - not long to wait now.... Much less time to wait than designing an electrostatic DAC/amp, that's for sure.

Rob

You could design it in an afternoon but you'll have to spend six months writing and rewriting code to get it right though Rob.

 

[romaz]

   Sadly my upper limit will be dropped to 11.35 kHz till then.

 
Slightly off topic but I presume you're joking about your upper limit of hearing although if you're a musician or you listen to your music very loud, maybe you're not.
 
As a physician in my real job, I can tell you that by age 25, most of us are unable to hear signals above 15 kHz.  I know I can't and it's just a fact of life.  As we age, this gets worse but depending on your line of work or routine behaviors (musician, military, construction, frequent IEM user), some of us lose our hearing more drastically.  Sounds discouraging but there's another way to look at it.
 
The frequency range of hearing, from 20-20,000 Hz encompasses 10 octaves.  From 10,000-20,000 Hz represents only 1 octave.  If you can only hear down to 11 kHz, that represents 0.9 octaves of high frequency hearing loss.  If you are a "glass half full" type of person, that means you can hear 9.1 octaves out of the 10 that are available.  That means you still have 91% of your hearing.  Doesn't sound as bad, does it?
 
If you guys are wondering what your upper limit of hearing is, here's a simple way to check:  https://www.youtube.com/watch?v=qNf9nzvnd1k

 

[bmichels]

   
Yes, please do! Let's say tomorrow afternoon? But I don't want to rush you... Next Monday is o.k., too.
 
Thank you, Rob!

 
Next monday will anyway be well before the BHSE that I just ordered will arrive (in 1 year ? ) 

 

 

[JaZZ]

 

   Sadly my upper limit will be dropped to 11.35 kHz till then.

 
Slightly off topic but I presume you're joking about your upper limit of hearing although if you're a musician or you listen to your music very loud, maybe you're not.
 
As a physician in my real job, I can tell you that by age 25, most of us are unable to hear signals above 15 kHz.  I know I can't and it's just a fact of life.  As we age, this gets worse but depending on your line of work or routine behaviors (musician, military, construction, frequent IEM user), some of us lose our hearing more drastically.  Sounds discouraging but there's another way to look at it.
 
The frequency range of hearing, from 20-20,000 Hz encompasses 10 octaves.  From 10,000-20,000 Hz represents only 1 octave.  If you can only hear down to 11 kHz, that represents 0.9 octaves of high frequency hearing loss.  If you are a "glass half full" type of person, that means you can hear 9.1 octaves out of the 10 that are available.  That means you still have 91% of your hearing.  Doesn't sound as bad, does it?
 
If you guys are wondering what your upper limit of hearing is, here's a simple way to check:  https://www.youtube.com/watch?v=qNf9nzvnd1k

 
I've been a bass player in a band / in bands at younger ages, but my hearing loss is just from my age: 65. I recently tested it: I hear up to 13 kHz, which sounds even a bit louder than 12 kHz, but still quite low. I'm not complaining – but the guessed limit of 11.35 kHz in almost four years is not too unrealistic (although a bit pessimistic on purpose – to put some pressure on Rob).
 
I agree that it's still a bandwidth enabling to enjoy music in high quality, and frankly I don't miss the now missing 4 kHz compared to the age of 25 or so. But I'm sure the quality of the equipment will play a less important role with shrinking hearing bandwidth.

 

[Beolab]

Slightly off topic but I presume you're joking about your upper limit of hearing although if you're a musician or you listen to your music very loud, maybe you're not.

As a physician in my real job, I can tell you that by age 25, most of us are unable to hear signals above 15 kHz.  I know I can't and it's just a fact of life.  As we age, this gets worse but depending on your line of work or routine behaviors (musician, military, construction, frequent IEM user), some of us lose our hearing more drastically.  Sounds discouraging but there's another way to look at it.

The frequency range of hearing, from 20-20,000 Hz encompasses 10 octaves.  From 10,000-20,000 Hz represents only 1 octave.  If you can only hear down to 11 kHz, that represents 0.9 octaves of high frequency hearing loss.  If you are a "glass half full" type of person, that means you can hear 9.1 octaves out of the 10 that are available.  That means you still have 91% of your hearing.  Doesn't sound as bad, does it?

If you guys are wondering what your upper limit of hearing is, here's a simple way to check:  https://www.youtube.com/watch?v=qNf9nzvnd1k

I hear 20hz-18khz when i do the tests, and im 34 years old, and can hear a the high pitched frequency that is generated when a CRT TV start up on a different floor, and the half or full glass of water test

I just play High End loudspeakers very load at my work

 

[Sonic77]

Take your time with digital amps, I'm happy with what I got, plus I can save some money, or buy some headphones.

 

[analogmusic]

One million lines of code? not sure how this works, but is this even possible by one single person? How would this work? Is some code a repetition?
 
Anyway was listening to my Hugo in the car, and it really does the job musically, on some old INXS albums which I know very well, the music sounded punchy, fun, and vibrant.
 
I can't think of anything that I could wish for, so maybe the DAVE is really enough for us musically !
 
About the encoding side, once record companies get their DAVINAS for encoding from 768KHZ rate (or analog masters - apologies if this upsets anyone)  back to 44.1, I hope we can finally listen to music the way it was meant to be heard by artists.
 
But honestly with Hugo (haven't heard DAVE), I think we are already pretty damn close.

 

[m0nster]

Take your time with digital amps, I'm happy with what I got, plus I can save some money, or buy some headphones.

Haha, you wish that you'll save some money. I bet you'll find awesome headphones first. Or a new DAP. Or you get a second DAVE, because it's just that great