electronic systems in 4 main categories interfered by EMF

category I) Glass tubes with simpler hard wire circuit
moderate distortion - most old systems of the 60s' are simpler hard wire circuits with low power output about 4 to 8 watt thru the output transformer. That's why this sounds better than the other 3 kinds of systems as stated below though it's not as good as live but it's still good enough, at least it sounds sweet.

category II) Glass tube with printed circuit board
high distortion - we call this modern tube systems as they applied PCB with bare tracks instead of hard wire circuit, though they don't sound as good as the category I, it's still sound better than any solid state systems.

category III) Solid state with complex circuit on PCBs
severe distortion - being too complex with the circuit on PCBs with bare tracks and getting interfered by EMF more easier. At least there shall be 2 or 3 times higher distortion than category I & II . The higher power output of these systems tends to have higher distortion.

category IV) Solid state - Vacuum tube hybrid
seriously distorted and unclassified - I can say any sytems made this way with PCBs sound annoying and even worse than any systems as stated above and never pleases anyone's ears. Some D/A converters, CD players, pre-amplifiers, power amplifiers also made this way sound real bad or inferior. What I can say is 'Sorry'.

Don't forget that most branded manufacturers stress that the systems they produced are gone thru perfect squared wave test.

There are so many people or audiophiles who are asking why they have spent lots of money in their components and systems, why their systems still don't sound as real. Here you can find out one of the answers...

If you're also interested in audio/video enhancement, you may also download a Word file at the link below:

http://cid-d48d1ea0d5766c81.skydrive.live.com/self.aspx/.Documents/Sharing%20my%20tweaks%20and%20endeavors%20in%20hi-fi%20stuff.doc?lc=3076

Those systems with PCBs shall apply aluminum based PCBs, then the sound quality will be improved to a certain extent because such kind of metal based PCBs shall have a few properties that can shield up electric field and reduce heat of the systems to a certain degree. Then you would fine output quality of audio and video improved a lot.

You may also visit the site below for info in understanding advantages of Aluminum base PCBs.

http://www.standardpcb.com/