I would very much love to hear this behemoth build. Good luck to Aries Cerat for going balls out to concoct a space ship DAC - the nutty highend needs people like you - I mean that as a real compliment.
Thanks Stavros, but I am in Geneva, CH closer to your hope in Cyprus. LoLThank you for the link.
Maybe we could talk about DHT magic at CES.
The Siemens E280F are far the best of the bunch of E280F not only sound wise,but construction quality and consistence as well.
I will share some info.
High transconductance tubes like the E280F are usually all over the place mu-gm wise,as the slightest variation on grid pitch,and i am talking about micro scale,you have large deviation.
So ,testing a dozen of valvo tubes,dozen of Philips on my custom valve tester-tracer, i got variations up to 1V offset on curve trace,from tube to tube.Siemens were 0.1V which is something amazing and cannot believe the quality control they had back then,
Do not get me started on Philips dark and mellow sound
I will bring some with me,if we do have time at CES we can compare so you can hear "first hand"
Stavros
I am not surprised that Siemens/Telefunken and RSD (sp?) have such solid construction.
Phillips/Pope/Valvo Amperex depend on the date and factory used. They are not all created equally, as I am sure you know.
Well I hope everyone had the chance to enjoy some turkey and gravy comas over the last few days
I hope now without much questions pertaining to the explanation of weight in the Limited Edition chassis that we have ironed out that most of the weight contributed to the Aries Cerat design is certainly not just for show. Many points have suggested that the design is "over" engineered, but based on what? If I could shift your perception to the possibility that most of the designs today are "under"engineered to fit a certain price-to-margin ratio or to fit a price point thereby introducing compromises. As you can imagine, building anything weighing as much as even the reference DAC at 120lbs and dimensions of 24W X 24L is not going fit the "typical" or "mainstream" perception of DAC design
With an Aries Cerat anything at the very least you can physically see/feel where your money is going towards.
Which begs the question...? How do you determine what DAC you will look to buy? Are your buying instincts parts focused or more on the proprietary circuits used to achieve "X".
I use Audio Consulting MIPA amplification (Serge swears by being independent from the grid), so I would be interested, why did you opt for a "quasi battery" operation, but did exclude batteries?
Paralleing converters cannot and will not reduce jitter.Maybe i got Joshua confused somewhere
Here is our approach on jitter.
We use many techniques regarding lowering and canceling jitter,passive and active ways.
Bouncing digital signals, overshoots, low rise times etc greatly increase jitter. We solve this by using special digital driving circuits,tuned buffers and carefully tuned digital line terminations for all our digital signals,so we elliminate the creation of jitter through the ways described above.
Crosstalk between digital lines, ground noise and power supply noise and crosstalk is a major source of random and deterministic jitter. We use extensive LC filtering(using high loss RF chokes and high speed capacitors) to all ICs ,power rails and logic circuits,(up to 70 separate filters) to solve this problem.
Jitter originated in USB and Spdif/Toslink sources is canceled right at the conversion-enable line, or the ”refresh” signal of the converters.
Having an IC that is has no complex data handling logic and no multi stage data logic, the highly precisely timed signal, resolves in a extremely accurate jitter free conversion.
This is not possible with any other converter,as there will be always internal logic and data handling, vastly deteriorating jitter performance, even if the clock input is close to perfect.
The Super clock is also used upstream, for reclocking the XMOS asynchronous usb controller, as well as the SPDIF receiver.
Our recklocking techniques are glitch free and does not require for additional clock inputs-outputs for the rest of the audio chain,such as the transport.
Most important aspect of the techniques we use,it that there is absolutely no further digital data handling AFTER the recklocking of the word sync,or "refresh signal" so no jitter can be created further downstream,
Jitter is very much audible, and I felt that the dichognomy must end. That is why the digital input re-clocking circuits are bypass able on the fly, so every audiophile can make a AB comparison ,on the fly, with the turn of a knob.
Below are some measurements on the modulation domain(i find jitter measurement on analog domain useless),jitter distribution of a typical "high end" transport, jitter after first reclocking ,and after second reclocking .
A very interesting fact ,is, that batteries,are very noisy ,when they are used as power source for modulated DC signals.They present high energy noise when asked to feed circuits with modulated signals. They would need heavy filtering as well.
This along with the following points
-Battery replacement cost-trouble of returning the unit to dealer
-Battery maintenance issues
-Safety issues( as with all battery systems)
-Cycling etc
make the battery non ideal,at least from my perspective.The use of the "quasi-battery" method is optimal for what we are after.
HI Aries Cerat,
thanks for continuing to post...i am no techie and [try to] follow along. Much is made out of the selection of the DAC chip itself. BB1704, ESS-9018. I believe you selected the AD1865...i note that Audio Notes DAC 5th Element (in a similar price bracket as your mighty Kassandra) also uses this chip. (no doubt, so do many other DACs?)
1. Why this particular chip?
2. Without getting into anything too controversial, is there a big difference in the design between the all-out Audio Note DAC 5th Element which comes in 2 boxes, one with a 35kg power supply, chokes, special wires, etc, etc?
thanks for continuing to post...i am no techie and [try to] follow along. Much is made out of the selection of the DAC chip itself. BB1704, ESS-9018. I believe you selected the AD1865...i note that Audio Notes DAC 5th Element (in a similar price bracket as your mighty Kassandra) also uses this chip. (no doubt, so do many other DACs?)
1. Why this particular chip?
2. Without getting into anything too controversial, is there a big difference in the design between the all-out Audio Note DAC 5th Element which comes in 2 boxes, one with a 35kg power supply, chokes, special wires, etc, etc?
Thank you for the questions.
Please allow me not to comment on another manufacturer's design.
The 5th Element technical description is available and one can compare.
Now,about the IC,a short answer would be,because it sounds best
but this would be irrelevant,as our converter banks sound nothing like the plain IC .We chose to use an R2R IC,in our case the AD1865Nk, a much appraised converter. Many DACs use the IC converters, in the usual “data sheet application” circuit, just adding their analog stage ,PSUs and ,voila.
We choose to design a converter that uses a number of IC R2R converters as components to a complete new converter system.
The major advantage of the AD1865Nk is that it has a very straight forward data handling logic,and does not process the data stream in any way.It just latches the serial data and refreshes the resistor network state. This gave us freedom to fully exploit the IC ladder network as component on our converter system.
For example, the input data are latched ,and the resistor network can be directly refreshed,with absolutely no additional complex logic or data handling /processing.
Our SuperClock circuit,directly re-clocks and drives the “refresh” signal, so absolutely no additional jitter is induced in the conversion. This is not possible by any other IC converter, as there is always internal logic and data handling, vastly deteriorating jitter performance, even if the clock input is close to perfect.
The massive banks of the IC converters, act as parallel switched resistor ladder converters, thus canceling the deviation of the actual resistor values vs the theoretical.
If the deviation of the resistor value from ideal, is Gaussian(which it is),as the number of parallel resistor networks increases, the deviation from ideal is driven to Zero.
This is why paralleling R2R converters, improves linearity.
Noise figures are improved, on the same principles.
The Kassandra converter is working in complementary mode.Each channel is consists of two converter banks which are “mirrored” ,perfectly synchronized by quadruple clock,quadruple data and master clock buffers,and are matched.This further improves low level linearity(the linearity near “zero” value),as well as it lowers noise.
Thank you Aries Cerat. I think if i had to take a test on what you said...i would definitely not pass! But i do have an appreciation of what you are saying, and i am sure there are others here who understand better what you are saying as well.
It is always great to learn (even a little) from people who are truly knowledgeable and actually executing in the real world at the professional/industrial level. Where can one hear a Kassandra?
But i do have an appreciation of what you are saying, and i am sure there are others here who understand better what you are saying as well. It is always great to learn (even a little) from people who are truly knowledgeable and actually executing in the real world at the professional/industrial level. Where can one hear a Kassandra?
Correct. As a US distributor many ways we can arrange for an audition, but outside of the US I would try to make a trip to the next munich show.
You can always press your local folks to pursue dealer/distribution in your country and come listen to see if they want to carry the brand.
Stavros should have been at the Warsaw show this year (early Nov.), Europe's 2nd biggest show with circa 150 rooms in 3 venues. It also has the best room acoustics and is the most consumer forcussed. Elberoth here is the person to speak with about seting that up.
Other than Munich/Warsaw, Stavros should consider London and Paris shows.
Other than Munich/Warsaw, Stavros should consider London and Paris shows.
Perhaps you can help him out with that. I have him focused on CES with a full Aries Cerat system, but to pursue other venues that are not as International focused by himself would be challenging. Selection of partners to help with setup and costs of these things is pretty tough. If you know some folks that have excellent gear refer them to Stavros so he can try and make it
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