Denafrips Pontus II Clicks Or Static?

Are you using the same cable, or different coax cables. Try switching and see if the problem switches.

@All

i just finished this entire thread and boy my head hurts.  The only reason I landed on this was after listening to Audio Science’s Amir explain the jitter, Dac clock vs source clock, pll and how that works and noticed he had not tested the Pontus ii, so I went a googling.

i purchased a Pontus ii 12th Anv. Which arrived today and is sitting boxed in my basement.  Now I’m afraid to open it 🙄.  Seriously, it’s replacing and old Burson DA 160 which I’ve loved over the years, but it seems to be choking on the new Eversolo A8.  Anyway, I am coupling it to an Audiophonics HPA Purifi D class and will report back should I hear any of those pesky pops.

I have had this issue, but isn't frequent enough in nature to be a problem. At least to me anyway. The noise I get from my Pontus ll is a extremely soft low level pop, which happens maybe twice during a 3 hour listening session. While I would appreciate dead silence, it isn't that offensive to bother me. Pops, clicks, and snaps from vinyl are FAR more annoying than this.

I had the same issues about a year ago, Alvin had me do a firmware upgrade, that resoled the issues for 90% of the time, a month ago I did the new firmware upgrade, sound was good more detail, started checking left and right plus polarity, when I would Roon and play back was DSD left and right where backwards, through pcm play back it would be just the opposite and phase was off. Alvin replied that I had to change the phase through some programing he gave me, did and I thought problem was resolved, not , I had to go through 8 steps to get the correct I2s config, that also was effectting left and right ch.After all that now the small clicks and static are back. Just sent Alvin an email, had to share.

Thanks @jaytor – I appreciate your technical insights. I tend to believe that it was likely a (Denafrips) clock issue, but whatever the exact cause, I hope that the latest firmware has resolved the issue for owners of the affected DACs. 

@whipsaw - I am making some assumptions here on the exact implementation of Denafrips' designs, since they have never really published a detailed description.

As I understand it, the input data is clocked into the FIFO using the source device's clock (embedded in the SPDIF signal), and clocked out of the FIFO using the DAC's internal clock.

If the clocks are different enough in frequency, eventually the FIFO will overflow (if the source device's clock is faster) or underflow (if the source clock is slower). So, yes, CISCO's explanation is basically correct.

I'm not an expert on modern DAC implementation, but I believe that many DACs (particularly lower priced DACs) use a phase-locked loop to adjust the DAC's clock frequency to match the source clock. They may also use a FIFO so the PLL can be slow responding to minimize jitter. But a PLL will still not be as stable and jitter free as a fixed crystal oscillator (particularly an temperature controlled oscillator).

I suspect the reason that the problem was less common (or non-existent) with the Terminator and T+ is that the clock used in these DACs is higher quality (more accurate) than the clocks used in the lower priced models, and these DACs probably also tend to be used with higher quality sources (which have more accurate clocks). I have not heard that the FIFO implementation is any different, although it's possible that larger FIFOs were used. 

I also suspect that many higher end DACs use a similar approach to Denafrips and just did a better job with the FIFO management (perhaps using the same approach that Denafrips is now using). 

@whipsaw - You can call it a hardware problem if you want, but IMO, it was (is) a rational approach to solving the problem of jitter reduction of source-clocked digital data.

@jaytor  If it was not a hardware problem, then how would you explain why other manufacturers of higher-end DACs have not encountered such problems? Jitter reduction is essentially a "settled issue", even in much less expensive DACs.

My understanding, though I could be wrong, is that the issue was not reported by users of the Terminator DACs. If that was the case, and it was a software issue, then why would it not have been a simple matter to resolve?

Finally, as you have a technical background, does this Cisco explanation of FIFO overruns not apply here? And if not, can you explain why?

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.

@whipsaw - You can call it a hardware problem if you want, but IMO, it was (is) a rational approach to solving the problem of jitter reduction of source-clocked digital data. I'm sorry you experienced problems with your DAC.

With their implementation as I understand it (and I am a digital electronics engineer), there is no "definitive" fix if the source and DAC have significantly different clock frequencies. I suspect this new firmware either increases the amount of RAM allocated to the FIFO, changes the algorithm used to reset the FIFO pointers (e.g. between every song), or both. This won't fix all possible cases, but it will likely reduce the percentage of users that experience the problem from an already small number to near zero.

I don't know why Denafrips chose to wait as long as they did to issue a fix. It could be that other more significant changes were required to the firmware to allocate more RAM for the FIFO, or it could be that they just felt it was affecting so few users that they had other priorities. 

At any rate, hopefully this will fix the problem for the users that FIFO overflow/underflow was affecting. 

I'm quite happy with the sound from my T+, but I'm looking forward to being able to try out this new update. I've never experienced any skipping/glitching issues, but I have always used my T+ with a USB connection to my streamer (through a Gaia). 

I have an Ares 2 and a Pontus 2.  The only time I’ve had static or popping sounds was with the Ares 2 connected to a Bluesound Node N130 via USB.  Using coax was fine.  I then swapped out the Node for an iFi Zen Stream via USB and never had a problem after that.  Using that same setup with Pontus 2 and never had an issue.

I updated the firmware on both DACs today and it was very easy. Used a MacBook Pro and had no issues.  The instructions were very clear and easy to follow.

Both DACs sound a little better to my ears after the update.  Was definitely worth doing.

I'm waiting for the file to apply the firmware to my Pontus II.

I have owned this DACs for over 3 weeks and have not experienced any pops or clicks while streaming music. I'm in-between owning a CD transport. However, like my Ares II (SOLD), I've experienced a split-second 'drop-out' or minute skip in the music. It's so small, that its over before you realize. Never in more than one place in a single song, and always at the beginning of a track. And lately, it hasn't occurred at all in a week of (75-100 hours) listening. I just hope this glitch goes away for all of Us. 

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.

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.

@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?

@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.

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.

@atp001 

With respect to the topic of this post and the issue I personally experienced, the firmware appears to have corrected the problem.  Thus logically, it was a software related issue.

Has it done so for every user that experienced issues, and irrespective of the source? That's a rhetorical question, as obviously no one knows the answer to that question. So no, I do not agree that it is logical to extrapolate from your single, anecdotal experience, that it was therefore a software issue.

Even if the software patch were to prove 100% effective in eliminating the problem, it doesn't mean that there isn't an underlying hardware problem. And again, if it was a pure software issue, how could it possibly have taken so long to resolve, and why would Denefrips still be hedging (i.e. "reduced")?

I would argue that the available evidence continues to strongly suggest that it is a hardware issue, and that efforts have been made to mitigate the problem through a much less expensive approach than a recall and hardware fix.

As for issues relating to the quality of the sound produced by Denfarips DACs, I have made no disparaging comments beyond the narrow topic that we are discussing.

@stevebohnii 

I did get a sense that the sound improved on the Ares II with the new firmware (separation, imaging).  Was that due to expectation bias, I cannot say.  Unfortunately my sound memory is poor.

@atp001 - how long did the upload/update take? People who have updated their Ares ii heard a big improvement in sound quality. Did you experience that with your Ares ii upgrade or was it similar to the Pontus upgrade and no major audible improvement? Thanks for taking the time to answer all my questions. 

@whipsaw 

With respect to the topic of this post and the issue I personally experienced, the firmware appears to have corrected the problem.  Thus logically, it was a software related issue.

Now, regarding other aspects of the sound quality that you are speculating about, the Ares II and Pontus II have received almost unanimous acclaim for their sound quality.  If the new firmware improves (at least objectively) on that sound, then I'm happy for it.

@stevebohnii 

I suppose I was lucky in that I communicated my issue with Vinshine just as they were preparing to announce the new firmware update.  So I got early access.  If the sound has improved in any other way, I have not noticed. 

@atp001 - how did you get the new firmware for the Pontus ii? Alvin said the update would not be available until the beginning of April. In addition to eliminating the pops, did the upgrade improve sound quality? If so, how? 
 

@whipsaw - you make a great point. Reduces is a lot different than eliminates. 

I have been playing my Pontus II with the new FPGA firmware update for about a week now and I can confirm that the random pops/ticks I was experiencing are now absent. This mirrors my experience with upgrading the firmware on my Ares II. So it seems the issue was in fact software based.

I am skeptical of that conclusion, as if it were true, there is no reason that the problem could not have been fully resolved. Instead, we get this:

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

"Reduced", not eliminated. What this suggests, and I would say clearly, is that it is in fact a hardware problem, which they are attempting to mitigate with a software patch.

Perhaps the approach will prove effective in reducing the audible artifacts to a very low level. But as I have pointed out numerous times previously, there is no reason that such a problem should exist in a relatively expensive, otherwise high-quality DAC. In other words, it is either a design flaw, or corners were cut on the related hardware.

I have been playing my Pontus II with the new FPGA firmware update for about a week now and I can confirm that the random pops/ticks I was experiencing are now absent.  This mirrors my experience with upgrading the firmware on my Ares II.  So it seems the issue was in fact software based.  Below are the changes associated with the new firmware as described by Alvin at Vinshine:

"Notes:
1. The FPGA firmware update is for all DENAFRIPS DACs with the latest FPGA BGA chip.
2. It does not apply to the older DSP (Amanero, released in 2017-2019). If you have a DENAFRIPS DAC purchased after 2020, in general, it is upgradable.
3. The firmware update fixes some bugs, and enhance the sound quality for all digital inputs
4. The firmware update changes the NOS response to what Vinshine Audio believes it's NOS (Raw, Staircase Waveform output for 44.1kHz / 48kHz)


Areas of Improvement:

• Improved Adaptive FIFO Buffer & Reclocking Architecture
• Reduced the effect of Buffer overrun/underrun due to the Source's Clock and the DAC's Clock differences
• Reduced Audio Latency
• *Eliminate Phase Difference between L/R Channels
• Optimised DSP to improve the sonic performance"

I have to commend Vinshine for being very responsive to the issues I was having.  Never did they claim this would fix my problem with certainty.  I think their stepped approach to troubleshooting this issue was appropriate and worked out me in the end.

So if this was a software issue, why is the issue not being reported by more people?  I don't have a good answer, but I tend to have very analytical tendencies.  When I listen to music, I listen equally to my equipment.  I would not be surprised if some Denafrips owners have the issue but haven't noticed because of the way they listen to music or perhaps to the type of music played.

I have had my Pontus II nearly two years and have never experienced any pops or clicks. I run mine in NOS mode and use a Coax connection to my CD transport and Toslink to my streamer. I wanted to connect my Pontus simultaneously to both my McIntosh Integrated and my Topping headphone amp. Alvin at Vinshine stated that using both the XLR and RCA outputs simultaneously would seriously degrade performance. Alvin proposed a work around and sent me a design of a custom “Y” cable which connected to the XLR outs on the Pontus and split off into dual RCA connections to both amplifiers. I had the folks at Morrow Audio build this custom cable to Alvin’s design and it has performed flawlessly. I wanted to mention this performance degradation Caveat to anyone who wants to connect their Pontus to dual amps although it probably has nothing to do with this pop and click issue. I have been extremely happy with my Pontus and am very sorry to hear that this great product has been marred with this annoying defect.

FWIW, I have a Pontus II (non 12th).  I use mainly the Coax input and the I2S over HDMI input.  I do not use the oversampling modes. No clicks at all in the 6 months or so I have owned it.  True NOS or not, IMHO, this thing sounds wonderful, at least in the context of my system.  If I could wish for anything, it would be a slightly larger soundstage, although this is very source material dependent.

I would suspect that Denafrips would keep a low profile about having implemented a fix for the click and pop issue... for obvious reasons.  As to the NOS issue, and the fact that Denafrips now touts it as a TRUE NOS;  when I listen to the true NOS with my Pontus II 12th, it does not strike me as being nearly as "correct" as the slow oversampling filter (I realize that opinions may vary).  So, unless there were a recording that had some sort of unusual benefit from the NOS, I will just ignore the NOS issue. The NOS seems to do a slight blurring, and makes things sound more forgiving - which might be worthwhile with harsh sounding recordings.

A couple of related notes. While it is possible that the problem has finally been resolved, it was never apparent in the experience of all users, only (I would estimate) a relatively small percentage. So the fact that some users of the newest version have yet to encounter any problem, while encouraging, is far from being definitive.

Secondly, as I have mentioned previously, it would be odd for Denafrips to have found a (likely hardware) fix for the issue, yet make no mention of the fact if it was installed in this new version. Why would they not proudly – and loudly – announce a successful resolution?

The only reason that I can think of would be because it would alert unaware customers to the fact that the previous generations were vulnerable to the problem, and Denafrips does not want to engage in any expensive recall action.

One other interesting note. As I have also mentioned previously, Denafrips chose to basically ignore the fact that they advertised at least some of their previous DACs as having NOS capability, when that was false. Much like the skipping issue, I believe that the company ran an internal cost benefit analysis, and decided to gamble that most owners would either remain ignorant of the false advertising, or would not care much, as any sound differences were likely very small.

I mention the above because this appears in the marketing for the Pontus 12th:

Pontus II 12th is a true NOS DAC.

Now, that is obviously good news for those who have purchased, or will in the future purchase one of these units. But I would argue that it also confirms precisely what I have described, namely that the previous versions were not "true" NOS capable.

That the company was willing to falsely advertise at least some of its products, even after they were publicly exposed as not being NOS capable, is in my view very damning, and that behavior would give me pause in purchasing products from Denafrips in the future.

@fastcat95, maybe they have corrected it on the 12th.

I tried my Pontus II with 2 cd transports and 4 cd players, using 5 digital cables, with different terminations, bnc-rca, rca-rca, aes/ebu, and the problem is there. Once a day in some combinations and once in every song in others!

...but looove the sound :)

Enjoy your 12th :)

I am burning in a new Pontus II 12th, and have also not heard any of the clicks or pops that have been reported.

I have the Pontus ll and have never had clicks or pops, but the slightest static can make it do strange things! Lights changing when you run your finger over the top for instance.  Anyone do the update? What changed?

Pontus ll 12th here with about 300 hours on it. I’ve never heard a single pop or click. Just absolutely beautiful, warm and enjoyable music reproduction.

There was an interesting link provided by “Yage” in another Pontus thread relating how Benchmark approached intersample overs within audio tracks. He attached a link to their white paper within the thread linked below-

https://forum.audiogon.com/posts/2525335

@designsfx 

Thanks. I have mentioned this a number of times previously, but Alvin, Denafrips' representative in Singapore, was always very communicative and helpful. However, the company itself has, in my view, handled this situation poorly, and the likelihood of a firmware solution at this late stage seems extremely small.

I was also a bit put off by the company's choice to continue to represent at least some of their DAC models as having NOS capability, when it was, and possibly still is not the case.

To be fair, I was broadly happy with the sound and build-quality of the Pontus, but with so many other interesting options in the market, I was happy to take a small loss on re-sale, and move along.

The La Scala sounds superb, though I recognize that some would find it to be lacking in features that are found in some other DACs. They are expensive, but I am confident that in terms of both build and SQ, I would not be likely to find anything much better, and probably at any price.

The other reason that I went with Aqua is that their elegant modular design would allow for fairly simple upgrades in the future, should I be tempted.

@whipsaw 

Honestly- if they’ve been dragging their feet on this issue for that long you made the right decision in getting rid of the Pontus. 
How is your La Scala working for you? 

@designsfx 

Alvin originally told me that the issue was "likely caused by the FIFO buffer overrun".

The first attempted firmware fix was released almost one year ago.

@fastcat95 

In reading this I find it hard to believe that a reported issue like this has not been resolved by the manufacturer- I’m really sorry to hear about this. When you say “pops and clicks” are these similar to the sounds a dac makes when syncing up to a source or the sound sometimes heard when the incoming sample rate/frequency has changed from the playback source?

Good!   Keep us updated on the Pontus II firmware update, and also if it makes any change in the sound.

I am happy to report, to my surprise to be honest, that the firmware update appears to have fixed the problem with my Ares II.  I have listened to about ten hours of music since the update and have not heard any pops/ticks.  Although I feel it may be a little early to make any definitive conclusions, what I can say is that before the update i was invariably getting 1-2 pops/ticks per hour of playback.  So for now, the pops/ticks are no longer present.  

As whipsaw and fastcat95 had elaborated, I also thought the issue would be hardware related.  However, no pops/ticks are emitted when the dacs are idle nor when playing a low level test tone, suggesting the issue is signal dependent to some degree.  So maybe a firmware fix makes some sense?

I should get from Vinshine a firmware update for the Pontus II soon.  Let's see what happens in this case.

audiofilo123:

I received my Pontus II 12th on Monday, and it is currently burning in via the BNC coaxial digital input.  So far I have not heard any clicks or pops during operation. I am wondering if this problem could have a connection to particular digital sources. Hopefully, something will arrive as a solution to all this.  I second you on the build quality and sound of the Pontus II; even somewhat still raw at this point, it shows some very fine sonic qualities.

I have those reported issues with my Pontus II when using aes/ebu or coaxial front all my cd transports, but none ever through usb with the Auralic Aries.

I have been talking with Alvin Lee and trying all updates he recommended but the problem is still here.

Because I really like the Pontus II sound and build quality I will wait for promised firmware fix.

So far, in researching this subject, it appears that it is a minority of people who are experiencing the pops & cracks.  The problem, when it exists, would have to be likely one of four basic things:

1.  Fundamental hardware problem (unlikely, since only a minority have the issue)

2.  Fundamental firmware problem (also unlikely with a minority issue)

3.  A Random occurrence based on manufacturing/component variables (possible)

4.  A random occurrence based on both hardware variables and firmware interactions with that. (possible)

Some people report NO pop & crack issues, some report occasional issues, some report regular issues, and some report that the issue goes away with a firmware update. Just about everyone likes to basic sound of the Pontus II.

Regardless of what is causing the issue, Denafrips and Vinshine need to get a handle on it.  If the problem goes onward, the word will get around, and there will be a drop in product sales.

Alvin at Vinshine has mentioned a firmware update in one of his most recent videos.

As suggested above in my initial post, I do not believe that any firmware fix has resolved the problem. It may be possible that it has helped in some cases, but I am certain that if the problem had been fully resolved, Denafrips would be shouting it from the rooftops!

Given the length of time that this has been a known issue, I really do not understand how anyone could be optimistic that it might be fully resolved by other than a hardware fix.

Pops/ticks are present on all recordings and they are not repeatable.  The level does not appear to be correlated in my case.

I have been provided new firmware by Vinshine.  I will post my findings once that change is implemented and tested.

The review at goldensound talked about digital levels that went to or over the 0dB level causing problems with the Pontus. Regarding the clicks and pops; do they happen with certain disks, or just ANY disk (regardless of the level of recorded peaks)?  Can the clicks and pops be repeated using the same disks?  Are there disks where there are no clicks or pops?

This issue needs to be kept in the forefront of both Vinshine and Denafrips in the way of a firmware update that would eliminate or reduce the problem.  Alvin at Vinshine has mentioned a firmware update in one of his most recent videos.

I am very familiar with the issue, and it ultimately caused me to sell my Pontus II. I now use an admittedly much more expensive Aqua La Scala DAC, but would likely have continued with the Pontus were it not for that issue and the way that it has been handled by Denafrips.

This has now been a known issue for at least a couple of years, and no, as far as I know, there is no software/firmware fix. So I believe that the company made a calculated decision to engage in damage control, rather than offering a hardware fix, which would have been expensive, assuming that they have the knowledge to execute such a fix.

There was also what I consider to be an effort to obfuscate, or deflect blame, by floating the suggestion that it was only happening with certain transports. I had the issue with a Moon 260DT, which is a high-class machine, and in any case, the Pontus is responsible for the problem, as it should obviously work smoothly with all transports.

No issue on my Ares I.

I suppose that it I were not focused on listening to the music I might not always notice the pops/ticks.  In that sense, one might say they are soft.

I would not characterize the pops/ticks as soft or loud, just audible and at music levels.

I have been communicating with Vincent in support.  He had suggested I try USB but I relayed that I am currently not using USB.  That was six days ago and he has not responded.  Not sure how that was relevant anyhow.  I would like the dacs to function properly using spdif.

atp001:

Are your ticks and pops loud, or more soft in nature?  What has the response from Alvin at Vinshine been like?

I had previously wrote to Alvin about the issue, citing a review of the Pontus II 12th at goldensound.com.

Denafrips needs to seriously address this issue.  In a recent video, Alvin has said that a firmware update will be coming this year. Hopefully this will be fixed soon; some people do not report problems with the ticks & pops.

Yes, I have this problem with pops & ticks on both my Ares II and Pontus II.  I get a pop/tick concurring at an estimated frequency of 1-2 per hour of playback (it may be more frequent, possibly masked by music).  Currently trying to resolve the issue with Vinshine.

I have been troubleshooting this for about a year now.  What I can say at the moment is that the issue appears to be specific to the Denafrips units.  The issue exists on two different systems, regardless of whether all the connections are via RCA or XLR or whether the digital input is through optical, coaxial, or i2s (do not use USB).  The issue is present when playing both CDs, or PCM/DSD files.  Warming up the units does not resolve the problem.  I have no issues when I send the digital to another outboard DAC (using the same players, pre, amps), or when using the internal DACs of either of my two players.  NOS does not appear to solve the problem. 

I tried playing a -120db 1kHz test 'tone' thinking the low/silent background would help highlight the issue better, but after one hour of playback, I did not hear any pops/ticks.  I need to run this test some more to confirm.  I do hear the pops/ticks when playing test tones from the Stereophile Test CD3.

Anyone with insights or solved this problem?