I’m intrigued by this microskipping problem. Do I understand correctly that this happens when the connected device is a cd player without isolation chipset? No matter the output (coax/usb/toslink)? Why is there so little information on this, don’t people use cd players with external dacs regularly anymore?
I have the Pontus II and the CXC and although the firmware update diminished the microskipping issues they are still here, from time to time. Rebooting the Pontus seems to reduce the issue for a while but then it comes again. Lately I have been looking into the Atoll DR200 Signature transport, and it is interesting so see on the technical description the following note: - Insulation of the digital signals with a specific 1:1 transformer dedicated to S/PDIF and AES/EBU signals. I wonder if this can solve the problem? If only I could borrow the Atoll... On the other hand, my Aurelic Aries Femto (connected with aes/ebu digital cable, or USB cable) doesn’t provoke the issue on the Pontus. The Aurelic digital output is very well designed.
No, there is not yet compelling evidence that an isolation chipset is the source of the problem. More importantly, even if that were to be established, it would still, essentially, be a Denafrips problem, as the issue has not, to my knowledge, been reported with high-quality DACs manufactured by other companies. I had the issue using a (high-quality) SimAudio MOON transport through a Pontus, and the problem disappeared completely after I replaced the Denafrips with an Aqua DAC.
Does anyone know if a Oppo 205 has a digital isolation transformer? If it does that doesn't bode well for this fault theory.
This is not a promotion but just to add context to the player in question. The Cambridge CXC, mentioned by Alvin, is a WIDELY reviewed item. It is purported to have “class-leading” jitter of “less than 150 picoseconds”. It is interesting to note that all of these CXC REVIEWS featured a WIDE VARIETY of DACs. The prices of these DACs were commensurate with the price of the transport (occasionally, more expensive ones were introduced for comparison). NONE of these review DACs caused problems relating to data loss, dropouts or micro-skips! It is ironic that there are Forum threads discussing whether the price of a transport makes any difference (i.e. given that the DAC does most of the qualitative work) and yet here we are in a situation where one is invited to own an expensive transport (or specially equipped model) to enable a Denafrips entry-level DAC to work correctly?
My experience with Alvin was uniformly good, and I think that he does an excellent job. But he is not the manufacturer, and, I believe, has been put in the difficult position of having to spin, at least to some extent, on behalf on Denafrips. What I mean is that this has been a known issue for a very long time now, and in spite of efforts on the part of the company to provide a firmware solution, that seems extremely unlikely at this point. His post yesterday strikes me as a misdirection, or attempt to shift blame. As @CrimsonFan notes above, it would be ridiculous for Denafrips to suggest that all is well as long as their DAC owners use CD players/transports that have a particular type of high-end output isolation. To my knowledge, this is not an issue that afflicts other DACs, and the evidence to date suggests strongly that there is a hardware flaw in the Denafrips design. If that is the case, it is easy to see why they would be reluctant to recall a large number of units, and repair or replace them. But it does seem as though time is running out, and some type of fair resolution needs to be produced.
It really is disappointing because besides for the occasional “blip” it really is a nice sounding DAC. It is silly to assume I should have to guess what unit I might buy (because it’s affordable to me) may or may not have the pre-requisite “isolation whatever” they mentioned.
Indeed true. Alvin, as main representative/distributor finds himself in the unenviable position of taking all the flak. It’s not the first time that the Jays Transport has been proposed as a solution. This has been offered throughout the course of the discussion and some members have (perhaps reluctantly?) taken this option to bypass the problem. (Always assuming it IS a long-term solution!) Yes, FMS, it’s the only reason I’m still here
Hey guys, In my previous post re: Digital Isolation Transformer is one of the suspicions. We have not ruled out that it could also be the SPDIF clock frequency differences between the transport and DAC results in the FIFO buffer overflow. Denafrips DACs use an internal reclocker when the DAC is connected using SPDIF or AES, which uses a small FIFO to buffer the PCM samples before they are clocked out using the internal clock to the R2R DAC. SPDIF (and AES/EBU) assume that the source controls the clock, but as we all know this can introduce jitter resulting in poor performance. By buffering the data and reclocking it, the DAC can all but eliminate the issues with jitter, but this only works well if the source clock is close enough in frequency to the DACs reference clock such that the FIFO can handle the timing differences for the duration of the stream. If the source clock is operating at a significantly different frequency from DAC clock, or the time between resetting the buffer is too long, the FIFO will either overflow or run out of samples and you'll get a drop out or stutter. It's interesting to note that not all CXN/CXV customers reported such an issue. I have contacted the distributor of CA in Singapore to acquire a latest CXN so that we could test it & identify the root cause in our lab. Until then, peace
After using an Ares II for the past 2.5 years I decided to upgrade to the Pontus II. Playing music with it for the first time today after letting it warm up overnight. I’ll need to live with it for a while but my super early, totally biased first impression is positive. It seems fuller and richer and I think there is better separation too. We’ll see how it settles in over time. I’ve only used it in NOS mode so far.
It’s not just Cambridge audio transports though. Others like myself use something else and have the same problem.
I'm thinking of doing the same thing, please check in with us again. Are you using the I2s connection, if so which brand and model cable?
No, I don’t have any compatible devices but I’m curious about that. My Bluesound Node 2i and CD player were connected to the Ares II via digital coax. But only one of two coax inputs on the Pontus II is RCA; the other is BNC. So I’ve got the Node 2i connected via optical until I get an RCA > BNC cable. I need the optical input for something else.
For future reference: My Pontus has two RCA coax inputs, because I requested it, they will also put a HDMI connector at the I2s input per your request, they don't charge any extra to make these changes as long as you request them before it's shipped. The BNC is supposed to be a better connection so you should be ok. I've had the Pontus for 2 and a half years now and it's always in NOS mode and sounds great.
Thanks, I would have requested two RCA coax inputs if I’d realized that. Oh well; I can adapt and I’ll likely replace my old CD player with a new transport at some point that may have more connection options.
@ubiknik, with that HDMI connector, I can plug my OPPO 203’s HDMI 2 (audio only) to this input? Also, are you making any changes in the settings of your Node 2i when using an external DAC?
It sounds like he is asking if it will work if the jack is replaced with a standard HDMI before it’s shipped.
I thought it already has an hdmi type connection for the I2S input that’s why i’m confused when he said they will put an hdmi connector in it’s place?? thanks @Synthfreek
Now running Pontus II which is smooth and detailed. Am using the Optical input because that's the only outputs my TV and CDP have. Is there a difference using the other inputs please ? Wouldn't mind shaving a little off the top end and even dropping the whole tone a bit. I would have to get an adaption switcher.
No, I have an earlier Node, I use it through RCA coax and didn't mess with any settings. I just recall having to choose between the rj45 or HDMI connectors and I chose HDMI. I never got to the point of having an I2s device to use so it's a moot point for me.
With my CXC the reported problem comes and goes. I change the components in my system one time each month and there were times that the skipping issue was very regular, noticeable several times per disc. Currently, with an Atlas Compass coaxial digital cable I am experiencing no issues at all! A bit confusing... I will wait for Alvin investigation
