Denafrips Pontus II Clicks Or Static?

In September of 2021, Alvin told me that the problem was "likely caused by the FIFO buffer overrun".

Here is an explanation of an overrun from the Cisco website support pages (bold emphasis mine):

Q. What are overruns on a serial interface?

A. Overruns appear in the output of the show interface Serial 0 command when the serial receiver hardware is unable to hand received data to a hardware buffer because the input rate exceeds the receiver’s ability to handle the data.

This occurs due to a limitation of the hardware. Overruns occur when the internal First In, First Out (FIFO) buffer of the chip is full, but is still tries to handle incoming traffic. The serial controller chip has limited internal FIFO.

Some chips, for example, have only 256 bytes of buffer space. Data from the network is received into the buffer, whereupon the chip attempts to move the data from the buffer to the router’s shared memory for the CPU to process. If the chip is not able to move the data from its internal FIFO buffer into shared memory faster than the rate at which data is received on the interface, then the internal FIFO buffer is full, incoming data is dropped, and the overrun counter is incremented.

@whipsaw 

Yes, my observations are anecdotal at this time and my statements were meant to reflect my personal experience only.

I'm not following your logic.  If a firmware update 100% corrects an underlying hardware problem, doesn't that hardware problem no longer exist?  Isn't software written to accommodate the underlying hardware?  Is the Cisco explanation mutually exclusive with a software patch that could correct the perceived hardware limitation?  Is the architecture of the Cisco device relevant to the Denafrips DACs?  Maybe an electrical/software engineer can help answer these questions.

@atp001

I’m no engineer, but again, everything about this saga thus far suggests that it was/is fundamentally a hardware problem, and that it has yet to be fully resolved.

Again, Denfrips said recently that the firmware:

• Reduced the effect of Buffer overrun/underrun due to the Source’s Clock and the DAC’s Clock differences

which is a not so tacit admission that it is a hardware problem, as further underscored by the Cisco definition.

Given that, at least to my knowledge, this problem does not occur in the vast majority, if not all DACs produced by other high-end manufacturers, the obvious implication is that there is a hardware/clock problem with the Denefrips design that is simply not found elsewhere.

Put another way, if every other manufacturer of high-end DACs can say with confidence that such buffer overruns are not an issue, while Denfrips remains unable to do so, is it credible to argue that they alone are unable to develop good enough, associated software?

So along these lines: I question why on my 2010 MacBook Air, Audio Devices, when I go to set/match sample rates why is the Pontus II always showing a 32 bit rate?

Also I'm disappointed with the technical requirements for the firmware update.  My laptop "Hi Sierra" OS has not been tested (it is last possible OS update) and one must use Terminal commands to accomplish the procedure...never done this.  Also my 2019 iMac is running the latests OS, also not tested. 

I have heard "soft" pops very occasionally, using i2S from an OPPO player... not an issue for me and I love the excellent sound from the Pontus II, especially SACD.

After listening to various thread inputs, and after nearly 300 break in hours with my new Pontus II 12th (I have not heard a single click or pop) - it would appear that it is a minority who are experiencing the click and pop issue.  If the Denafrips DAC hardware was "fundamentally" at fault, there would likely be at least a majority of users experiencing the problem.  It is more likely that this may be the result of DAC hardware/firmware interactions with particular digital sources and circumstances.  And I note that there are reports from users that the problem disappeared after they installed the latest firmware update. In the meantime my new Pontus continues to produce a very fine sound.