Perhaps this has been answered. I deduced that you have inequal volume between channels upto a certain point and later it becomes okay. If this is the case, most likely the volm potentiometer sliders are not making contact for the right channel initially or in rare case the are inqueal...
I also struggled with the 8 O clock issue and decided to open up the amp to see if the knobs are secured otherwise inside (you can use two different allen keys to open if you need to). There is no additional hold on the knobs - they pull out - its a bit easier to hold the PCB in chassis open...
That is a distinct possibility - however, opens up the debate on an amp that measures well, also sounds well. In this case it would be interesting to know whether this specific unit of bundled power supply was adequate in first place. Out of my expertise area of course.
I tried a linear power supply (36V) with the TB10D. I tested with FLAC files through USB - Topping E30. It was easier to discern the vocal nuances. - I felt the clarity was better with this. It would good to know if anyone tried this and their experience.
Thanks for sharing. Presumably you have tracked the performance over a longer time by now - how's the heat handling? Did you need to consider installing a fan?
Please see here - its mostly the length of cable that matters - that too as @amirm said - he's magnified the difference a lot. On a desktop we are always trying to minimise cables abd thicker cables tend to be stiffer. My 2 Cents...
CheapAudioMan is sorta inconsistent. He does not describe the sound signature in most videos and makes more generic statements - I thought. When he runs out of cheap stuff (below $600 as stated by him), he reviews Yamaha! Fun to watch though and he does have a good spread.
Thanks so much for clarifying. That means the choice of cross over for mid range driver has to be appropriate as to not overlap the sub. Never thought of it before!