Ok, follow up after further troubleshooting.  I was incorrect about the clicking only being on the right tube, it is in both.  I saw it better once it got dark and I turned all the lights off.  Something is causing the fluctuations in the power side of things and everything else downstream.  I have a few extra 6P15P-EV and a spare 6N1P-EV so tried swapping them with the backups to see if anything changed.  Nothing did.  I don't believe this is tube related.

Upon testing various points on the board for voltage readings, I noticed when placing the test lead on the OPT Blue Wire for the Left channel, the clicking increased quickly, then slowed again when I removed the test lead.  This led me to power down, wait, then revisit some solder points.

Long story short, I re-flowed all of the OPT (both left and right) wires to the PCB.  Cleaned up any excess dried flux in various places to ensure no bridging.  I didn't find anything significant but re-flowed to be sure.  Powered back up to the similar results, but reading at test points were much more steady than before.

I unsoldered the Left Channel OPT Blue Wire lead and left it hanging free then powered up.  Zero whining, zero clicking, zero voltage fluctuations, and all 5 test points nearly at target, well within range.  I believe I may have a bad OPT.  I'm waiting for a call back from Edcore to assist in further troubleshooting.  We'll see what comes from that once I hear back.  In the meantime, I will open the bells to see if anything obvious is inside.  

Stay tuned.

Using the most recent version dated 08-2025.  I believe this is the same you posted.  I am assuming you are referring to the two 220K 1/2 Ohm resistors.  These are now silk screened on the latest version of PCB (rev 2025).  

Edcore got back to me and we did some measurements and testing.  Not the transformer.  The issue only occurs when the Left Side Plate is under load when the transformer is hooked up.  I swapped transformers and the problem remained in the left channel.  So... not transformers and back to the PCB.  

Also found that once the clicking and whining goes on for a bit, both test point D's lose power entirely... wtf?  This got me thinking it's back further in the power circuit.

Followed every connection backwards.  Good solder joints at the jumper and resistor going back to socket pins 7 & 9.  Went further.  Every single capacitor measures within spec.  Every resistor measures within spec.  Started to get frustrated.  Went and pulled the diodes.  Voltage flowing both ways.  This could be the issue, but they were good when installed.  I suppose I exposed them to too much heat as @MM suggested.

I've got more coming tomorrow along with some de-soldering wick as my pcb is starting to look no so clean anymore...

Update.  Unfortunately, changing the diodes did nothing.  I finally figured out what was causing these HF oscillations and why my B+ kept collapsing.  I opted NOT to install an audio taper as I was going to control volume from my pre-amp.  Per another thread on the site as well as some outside forums, I simply jumped the RCA inputs to the center holes on the PCB where the volume pot would have gone.  While this did complete the input circuit, it was ultimately my issue.  Being that I am building on wood and NOT a chassis, I lost my DC reference to ground for the input tube grids, hence 0vDC reading at test points D.  Geez.  So I bought a 100k pot and installed with the jumper from the case to the ground plane.

Finally, I went through a stage-by-stage startup process to verify each stage as I went.  I got a stable power up and let it run for about 5 minutes before measuring all test points and all were in range.  Finally!

Next was to hook up speakers and get ready to battle the inevitable hum when building on wood.  Lol.  As expected, I got a pretty strong 120Hz hum at around 65dB when the volume was at zero with no source hooked up.  Geez, here we go again.

When measuring the RCA ground lugs to the negative 20uF negative leg, I kept getting jumpy reading for resistance. I tried a few things on the signal side but only one change made any difference.  When adding a 100 ohm resistor to each heater pin on the input tube, I did get a slight reduction in dB for the humming.  I decided to leave them in as there was a slight improvement.  I've got a 120Hz hum that I believe is ripple coming from the power supply.  Deciding between which is most effective, as I have to buy more parts to try either:

replacing the 20uF 250v Caps with 47uF >350v Caps - keeping the anniversary mod 0.1uF 600v in place

or

adding a third cap in the series by adding a 47uF >350v cap with the two 20uf 250v Caps

or

adding an RC Filter just for the input tube - probably a 1k Ohm - 2.2k Ohm resistor to feed the B+ followed by a 22-47uF to ground.  I believe this would isolate the ripple.  I'd add these at pins 1 and 6 after the 10k resistors, but am afraid I don't have enough real estate for all these added parts.

Ultimately, I opted not to build on a chassis on my first Decware build as I didn't want to put the time and effort into it until I heard the amp for myself.  But with all the added grounding issues from being on wood, I am quickly regretting that decision.  Too close to go back now, but if anyone else is reading this and on the fence, go for the metal chassis or do a hybrid metal chassis with the PCB still mounted on top.

Even with the hum, I went ahead and hooked up my source and am really enjoying the open sound stage and crispness in the upper end.  Some of the vocals are lifelike!  The hum is only head in between tracks or if there is a pause... still very annoying and I can see that 120Hz sitting there on the spectrum analyzer, but not always hear it.  Lol  Almost there.  In the manual, Steve says about 50 hours to run in and open up some more.  My only other complaint right now (outside of the humming) is the bass is almost non-existent below 100-120Hz, I sure do hope that opens up some sooner than later.  I've got a sub already hooked up and at the ready, should I need to turn it on.

Any additional help into this last humming issue would be greatly appreciated.

Cheers!