DK Design VS.1 Reference mkII - Optimization

Tvad, I'll take a stab at the vibration/top issue, by way of example. I have a CDP with case vibrations induced by the transformer. These vibrations are sufficient to rattle the tube innards which increases any potential they have to be microphonic. When I take the top off the CDP I'm eliminating one of the surfaces which facilitate the transmission of the vibrations. Often the audible (as well as physical) frequency (pitch if you will) and intensity of the vibration changes - usually lessens. Mass loading can have a similar effect.

If you have the best LN tubes and your unit has a low noise floor you might not actually change anything except reduce the audible transformer hum (not a bad thing at all), but if you have borderline tubes and a highish noise floor these vibrations can induce tube microphonics which can be audible. FWIW, I think there are better ways of getting 'spacious and open' than using microphonic tubes. :-)

Hey guys my thoughts were that removing the top changed the vibrational pattern and therefore the sound...for the better or for the worse. I am very comfortable with myself knowing that vibration can be given a pattern as well as direction in all things that are in motion, which is everything. Removing the case which is more likely less massive than the main chassis would probably reduce the amount of various resonance points that could be transfered back to the main chassis and electrical components to be reamplified in the mix. Most of you know my previous history and thoughts ..mass loading versus mechanical direct coupling..anyway the case removal altered the vibrational direction and flow..Proper mechanical grounding of all the boards, transformer and power supply caps to the main chassis and all of this direct coupled to a greater mass {the floor of your home} would transfer vibrational energy away from and out of your component..The result would be greater resolution and dynamic scale. So I have experienced.. Tom

I dont think vibration is an issue with the DK amp. It is a very massive peace of equipment and there is no vibration to speak of. This brings me back to the EMI issue. The concept is quite simple, some of the EMI bounces off the aluminum cover and goes back into the circuitry, creating a sort of a negative feedback circuit. When a small amount of signal goes back into the circuitry it gets amplified again. This is the reason I believe the amp sounds better with the cover off.

What I hear is that the midrange becomes even more open and organic when the cover is off. There is also a bit more detail and texture in the bass.