Oh, I think there's plenty of science to what TUC does, and its not down to showmanship or marketing. In many ways they go about it all wrong - making enemies on every internet forum, threatening legal action, refusing to send loan units to reviewers, etc. Think how effective they would be if they got their act together. The money back guarantee is a strong tool, but people aren't just reluctant to take any risk, they're reluctant to do anything at all. When I first got my kit, I tried to persuade other enthusiasts to hear it for themselves, even taking it round to their houses for free loans. But in all bar one case, they never even opened the boxes. And these were real enthusiasts with dedicated theatres. But its not my business, and after shouting myself hoarse on AVF and AVS, I gave up and kept to myself.
I was curious about the principles though, and far from keeping secrets, TUC now concentrate on advertising their EMI protection measures in their website. I've heard many instances of where a new product had been developed to perform well, only to see the SQ take a dive when its fitted inside a metal box, or when the lid is added. This made me think that players and processors in particular have a big EMC problem, which shouldn't be too surprising, with so many different technologies mixed together into one box.
I have two near identical integrated amps which sound the same as far as I can tell. One was a 100V Jap import that I converted to 240V using custom transformers and other parts. I took the opportunity to uprate them, hoping that would improve the sound quality into difficult speaker loads. Nomatter how hard I listened, I couldn't hear any improvement. Listener bias definitely wasn't working. I also tried some anti-microphony measures - panel damping, that sort of thing. Maybe a tiny improvement, but nothing worth the effort.
Now, I used to be an EMC R&D engineer in a previous existence, so I tried tackeling some of the presumed EMC problems. In one amp, I stuck some small ferrite tiles on each of the major IC's on each PCB (and there were a lot of them). Again, that made little difference. Then I tried to treat the amp chassis like an EMC anechoic chamber, and covered the heatsink and the inside of the box in RF absorbent materials. These suppressed over 99% of internal reflections from the steel box over a wide range of frequencies.
That made a World of difference; everything was better. Of course, I knew that everyone would say that I had imagined this improvement, having only performed sighted comparisons (even though I had honestly reported several null results). Therefore I got a few other people to listen to them blind. Not only did they express the same preference as me, but they also reported the same qualitative differences. I remember my daughter saying that the difference between them was like HD TV compared with SD, though not quite so pronounced.
Long story short, I therefore think TUC's approach in tackling internal EMC problems is a very effective one.
Nick
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