[adrianm]

deleted.. wrong forum!

It's ok, we'll be here, still waiting for you to join us...

 

[littlej0e]

Sorry but you are incorrect. The output from the volume control is simply not truncated - nor is it dithered - but aggressively noise shaped, so that the signals within the audio bandwidth are perfectly preserved. By perfectly, I mean it will reproduce a -301dB signal to an accuracy better than +/-0.001 dB and with a phase shift of within +/- 0.001 degrees; this level of accuracy is essential in order to maintain the perception of depth and detail resolution. To illustrate the power of this noise shaper look at the 16FS output of the M scaler's truncator to 24 bits:





You can see that the noise floor is at -390dB - and this is actually down to my test vectors. The noise shaper starts to kick in at around 16 kHz. Subjectively, this is completely transparent, in that there is no loss in SQ if a digital module can reproduce -301dB with zero amplitude or phase errors - from this perspective, then the volume control function can be considered lossless. All of my modules have to pass this demanding test, plus of course listening tests, before they can be incorporated into a design.

This approach is very radical, and to some would be considered excessive; but after many listening tests, it is the only way to accurately reproduce soundstage depth. Generally, digital volume controls are not done with such aggressive 11th order noise shaping - they are normally dithered when truncating, which is subjectively not lossless. Some don't even do that, just discard bits, which is just plain stupid/incompetent due to the severe small signal distortions introduced.

PS - just so you can see the -301.03 dB signal zoomed in:


The level is -301.030 dB, against -301.299957 dB ideal value

Ok...now what the does this even mean? Phrases like "subjectively transparent" and "subjectively lossless" are sending my bull-$hit-o-meter through the frickin' roof. Something is either fully transparent or it isn't. Fully lossless or it isn't. There is literally no grey area in those statements. So is the Dave DSP fully transparent and lossless or not?


I have absolutely no problem with you or Chord products, sir (quite the opposite, I'm actually a bit jealous I don't have a Dave...especially with the SJ power supplies ). I'm also not trying to put you on blast, search for any seemingly unpolished corner of impropriety to cast doubt on your very fine products as there is no doubt your DSP solution is both extremely clever and incredibly useful. I'm just after the truth because the statements above sound like very carefully phrased slight-of-hand marketing speak. Like an infomercial trying to sell me a rotisserie chicken machine, by using phrases like "virtually no cleanup".

Again, I can't stand people that mindlessly argue not to be wrong instead of searching for the absolute truth and that's sincerely all I am after here. I don't want to piss anyone off, hurt anyone's feelings, business, or opinions. I'm just looking for the simple truth.

 

[ra990]

...Something is either fully transparent or it isn't. Fully lossless or it isn't.

 

[littlej0e]

 

[Rob Watts]

The only thing is an optimised Dave and M-Scaler are state of the art. A Bartok is far from state of the art. There would be no point tweaking one as the designed is flawed in the first place imho. Most of the tweaks listed above are of benefit to any high end hi-fi system and are not required for the opto-dx. The opto-dx is the only way to 100% isolate the Dave an M-Scaler electrically as far as I know.

Opto-DX will only isolate completely if both sides of the Opto-DX are battery powered - otherwise you would get RF leakage via the mains. But if you are going to the trouble of installing batteries you may as well do it on the M scaler - then you would get 100% isolation too.

Ok...now what the does this even mean? Phrases like "subjectively transparent" and "subjectively lossless" are sending my bull-$hit-o-meter through the frickin' roof. Something is either fully transparent or it isn't. Fully lossless or it isn't. There is literally no grey area in those statements. So is the Dave DSP fully transparent and lossless or not?


I have absolutely no problem with you or Chord products, sir (quite the opposite, I'm actually a bit jealous I don't have a Dave...especially with the SJ power supplies ). I'm also not trying to put you on blast, search for any seemingly unpolished corner of impropriety to cast doubt on your very fine products as there is no doubt your DSP solution is both extremely clever and incredibly useful. I'm just after the truth because the statements above sound like very carefully phrased slight-of-hand marketing speak. Like an infomercial trying to sell me a rotisserie chicken machine, by using phrases like "virtually no cleanup".

Again, I can't stand people that mindlessly argue not to be wrong instead of searching for the absolute truth and that's sincerely all I am after here. I don't want to piss anyone off, hurt anyone's feelings, business, or opinions. I'm just looking for the simple truth.

I can see why you could say that your BS meter is going through the roof - but when I post I try to be as accurate from a technical sense as possible. You can't have a volume control that is bit perfect, as it obviously changes the data; you could call it lossless if you maintained accuracy - so 24b times 24b volume coefficient would give a 48b result that would be mathematically 100% accurate. But internally within a DAC if you kept that up the bit depth would rapidly cascade out of control. All the subjective evidence I have to date indicates that my tuncation noise-shapers are lossless from a sound quality POV; but if I were to call it absolutely lossless than that would be technically inaccurate, and posters would rightly post that I was being economical with the truth, and then turning it into marketing speak (which I despise and hate - so much damage is done in this industry by marketing BS).

Note that I did say "All the subjective evidence I have to date indicates..." and curiously one of the research programs I have in progress is proving that statement directly - what level of noise shaped truncation is possible after which it no longer becomes subjectively transparent - is a question I am looking into currently.

We are all looking for the absolute truth, but unfortunately that truth is rarely simple. My job in posting is difficult as I have to be 100% accurate, but at the same time trying to explain things simply...

 

[littlej0e]

Opto-DX will only isolate completely if both sides of the Opto-DX are battery powered - otherwise you would get RF leakage via the mains. But if you are going to the trouble of installing batteries you may as well do it on the M scaler - then you would get 100% isolation too.



I can see why you could say that your BS meter is going through the roof - but when I post I try to be as accurate from a technical sense as possible. You can't have a volume control that is bit perfect, as it obviously changes the data; you could call it lossless if you maintained accuracy - so 24b times 24b volume coefficient would give a 48b result that would be mathematically 100% accurate. But internally within a DAC if you kept that up the bit depth would rapidly cascade out of control. All the subjective evidence I have to date indicates that my tuncation noise-shapers are lossless from a sound quality POV; but if I were to call it absolutely lossless than that would be technically inaccurate, and posters would rightly post that I was being economical with the truth, and then turning it into marketing speak (which I despise and hate - so much damage is done in this industry by marketing BS).

Note that I did say "All the subjective evidence I have to date indicates..." and curiously one of the research programs I have in progress is proving that statement directly - what level of noise shaped truncation is possible after which it no longer becomes subjectively transparent - is a question I am looking into currently.

We are all looking for the absolute truth, but unfortunately that truth is rarely simple. My job in posting is difficult as I have to be 100% accurate, but at the same time trying to explain things simply...

Rob,

Thanks so much for taking the time to explain. I truly appreciate it. Even more than that, I now fully appreciate the extremely precarious and delicate situation you are in posting on a public forum and I never fully considered that when I asked my question. Sorry if I put you on the spot or in an uncomfortable situation and thanks again for answering. Your response makes perfect sense.

Lastly, congratulations on designing and building a fantastic DAC and DSP control. Even though it isn’t bit perfect, it should still functionality offset the increase/decrease in resolution, which is pretty damn amazing in of itself. I suspect your competitors will try to rip this off with a quickness. if they haven’t already done so.

Best wishes

 

[burbster]

The Dave and Blu2 were my starting point. It has taken some tweaking to where "I wonder if it can get any better"
Upgrades from the beginning:
1. Oyaide BD510 BNC cables with clip on ferrites.
2. Opto-DX with 3 m optical cables running on Batteries, removed clip on ferrites.
3. Farad Super 3 for Opto-Dx
4. 2 additional Oyaide DB510 BNC cables for Opto DX T
5. Intel Nuc running Roon Rock
6. Melco S100 switch with duplex single mode fibre to router. Finisar FTLF1318P3BTL SFP Optic Transceivers
7. Fiber Optic cable, Melco S100 to Ubiquiti edge router. CORNING part # 040402G5Z20020M, LC Duplex to LC Duplex Patch cord, 2 fibres, LSZH, 2.0 mm legs, SMF-28® Ultra OS2, 20 m
8. Ferrum Hypos power supply for Intel Nuc.
9. Intona 7055B with full galvanic isolation and no capacitive coupling for Intel Nuc
10. Separate analogue and digital power cables to consumer unit.
11. DFS 2 040-2/0/0.03-F RCD, Gigawatt G-16A MCB x 2 digital and analogue
12. Audioquest Niagara 7000 power conditioner for power amps and Dave and Opto-DX R
13. Audioquest Hurricane power cords
14. Original RSA Dmitri used to power Blu 2, digital source components and Opto-DX T
15. Upgrade premium single mode fibre optic cables for Opto-DX.
17. Distance (free upgrade!) My power amps, Dave and loudspeakers are at the front of my listening room. The Blu2 and digital source components are about 4 metres away along the side wall. The main advantage of the Opto-DX imho! Only the Dave, Opto-Dx R, power amps and Niagara 7000 are placed between the loudspeakers.
18. Investigating silver foil analogue RCA interconnects, Just ordered Blackcat SilverStar 88 Flatwave RCA Interconnects
19. Foil speaker cables ??
20. 6m tap M-Scaler ??

Note upgrades are not in chronological order.

Hi, Out of interest, did you ever try running the whole system off the audioquest 7000? Appreciate you have separate analogue and digital feeds from consumer unit, but I thought the 7000 had isolation transformers built into every source socket? (I may be wrong) but that gives you a good degree of electrical isolation (more than a separate circuit on the same consumer unit would) that way you get the isolation plus all the other benefits of the cleaned supply that AQ brings? I am trying to figure out if its worth running a further separate 'digital' circuit in myself, so curious to know your thoughts.

 

[audio_1]

Hi, Out of interest, did you ever try running the whole system off the audioquest 7000? Appreciate you have separate analogue and digital feeds from consumer unit, but I thought the 7000 had isolation transformers built into every source socket? (I may be wrong) but that gives you a good degree of electrical isolation (more than a separate circuit on the same consumer unit would) that way you get the isolation plus all the other benefits of the cleaned supply that AQ brings? I am trying to figure out if its worth running a further separate 'digital' circuit in myself, so curious to know your thoughts.

No. I wanted to isolate the Blu2, Opto-DX T, and digital source power supplies from the power amps and Dave as much as possible. I would also require very long power cords as my digital and analogue components are 4 metres apart. I already had the RSA Dimitri so always intended using it for the digital components.

I take advantage of the isolation transformers in the Niagara 7000 by having the power amps supplied from the high current power corrected sockets. The Opto-Dx R from one isolation transformer and the Dave from the other.

I hope that my system's power supply, reduces RF leakage via the mains as much as possible. (Niagara isolation transformer, 40 metres of power cable, 2 x power conditioners, multiple power cords and 2 x miniature circuit breakers.) The digital and analogue power cables from the consumer unit to my listening room are also spaced as far apart as possible in the attic for most of their length.

 

[burbster]

No. I wanted to isolate the Blu2, Opto-DX T, and digital source power supplies from the power amps and Dave as much as possible. I would also require very long power cords as my digital and analogue components are 4 metres apart. I already had the RSA Dimitri so always intended using it for the digital components.

I take advantage of the isolation transformers in the Niagara 7000 by having the power amps supplied from the high current power corrected sockets. The Opto-Dx R from one isolation transformer and the Dave from the other.

I hope that my system's power supply, reduces RF leakage via the mains as much as possible. (Niagara isolation transformer, 40 metres of power cable, 2 x power conditioners, multiple power cords and 2 x miniature circuit breakers.) The digital and analogue power cables from the consumer unit to my listening room are also spaced as far apart as possible in the attic for most of their length.

Thanks, you have certainly gone to great lengths to minimise any possible interaction between the circuits! For some time now I have had a dedicated audio ring main, but recently, through total lock down boredom, I went a step further and installed a dedicated consumer unit, fed directly from incomIng supply block, along with some modified internal wiring in said consumer unit and finally a screened 6mm cable to the socket. Sad I know!

 

[Triode User]

Thanks, you have certainly gone to great lengths to minimise any possible interaction between the circuits! For some time now I have had a dedicated audio ring main, but recently, through total lock down boredom, I went a step further and installed a dedicated consumer unit, fed directly from incomIng supply block, along with some modified internal wiring in said consumer unit and finally a screened 6mm cable to the socket. Sad I know!

My friend did similar to you. Unfortunately with my friends system I was able to demonstrate that his dedicated consumer fed directly from his incoming supply provided no RF isolation at all. A good test is to plug a mains wifi extender into one circuit and then plug another into the dedicated audio ring main fed from the separate consumer unit. The chances are they they will communicate quite happily via RF over the mains circuits.

 

[audio_1]

My friend did similar to you. Unfortunately with my friends system I was able to demonstrate that his dedicated consumer fed directly from his incoming supply provided no RF isolation at all. A good test is to plug a mains wifi extender into one circuit and then plug another into the dedicated audio ring main fed from the separate consumer unit. The chances are they they will communicate quite happily via RF over the mains circuits.

Hopefully the Blu 2 isn't feeding as much RF into the mains as a WiFi extender! I assume the RF leakage frequency is higher than a WiFi power line extender carrier frequency so will attenuate more. 40 metres of power cable, power cords and 2 power conditioners must reduce RF leakage a bit. Good test though. I will try it to see. I will borrow a WiFi power line extender kit and check. I don't see any other solution working for me. Batteries are unreliable and too much hassle.
This would also be a good test for the Niagara 7000 isolation transformers. I will test it between isolated outputs too.

 

[Rob Watts]

Rob,

Thanks so much for taking the time to explain. I truly appreciate it. Even more than that, I now fully appreciate the extremely precarious and delicate situation you are in posting on a public forum and I never fully considered that when I asked my question. Sorry if I put you on the spot or in an uncomfortable situation and thanks again for answering. Your response makes perfect sense.

Lastly, congratulations on designing and building a fantastic DAC and DSP control. Even though it isn’t bit perfect, it should still functionality offset the increase/decrease in resolution, which is pretty damn amazing in of itself. I suspect your competitors will try to rip this off with a quickness. if they haven’t already done so.

Best wishes

Thanks for your kind comments, and no you didn't put me on the spot - I am always happy to clarify, and never worried at all about being challenged on technical aspects.

 

[burbster]

My friend did similar to you. Unfortunately with my friends system I was able to demonstrate that his dedicated consumer fed directly from his incoming supply provided no RF isolation at all. A good test is to plug a mains wifi extender into one circuit and then plug another into the dedicated audio ring main fed from the separate consumer unit. The chances are they they will communicate quite happily via RF over the mains circuits.

So you are basically saying all my efforts were a complete waste of time!!! Thanks!

But yes I think you are probably right, I suspect they will work, but as Audio_1 states, I would also hope that the signal would be somewhat attenuated, if not what would be stopping your next door but two neighbor using a similar device to connect to ones in your house? (I say next door but 2, as that property should be on the same phase, but not always)
From my own experience the type of earthing arrangement you use on the dedicated circuit has more effect on RF attenuation. But that becomes quiet controversial as we can stray into non compliant installation's (BS7671) if we are not careful.

 

[OrenT]

Hi all, would appreciate your wisdom & experience.
Looking to upgrade from TT2 to Dave and came across this site:
http://diyhifiaudiophile.com/home/4...eadphone-amp.html?search_query=dave&results=3

Can this price possibly be legit or am I naive for even asking? Anyone from @ChordElectronics here?

Haven't found anything negative about them online, but when Googling their address, about 5 "fishy" (porn, anima) sites come up.
Also, I have contacted them and received professionally written replies (specifying total with shipping and insurance to my country), again, with their website and address in the signature.

Love to hear your thoughts. Thanks!

 

[genefruit]

Hi all, would appreciate your wisdom & experience.
Looking to upgrade from TT2 to Dave and came across this site:
http://diyhifiaudiophile.com/home/4...eadphone-amp.html?search_query=dave&results=3

Can this price possibly be legit or am I naive for even asking? Anyone from @ChordElectronics here?

Haven't found anything negative about them online, but when Googling their address, about 5 "fishy" (porn, anima) sites come up.
Also, I have contacted them and received professionally written replies (specifying total with shipping and insurance to my country), again, with their website and address in the signature.

Love to hear your thoughts. Thanks!

Based on the prices for other items, I find it difficult to believe they’re legitimate. I don’t know their end game but I am skeptical that an order placed would result in the item being delivered. On the other hand, what do you have to lose?