DK Design VS.1 Reference mkII - Optimization

Tom, Your explanation is as good as any I've seen for the reason this amp sounds best with the top off. Tubes are microphonic to some degree and the less vibrations (from any source) the better. Removing the top would certainly eliminate one potential source of vibrations. I've done this with some CDP's/Dac's and pre-amps.

I just don't understand these electro-magnetic 'waves'comments.

Apparently the amp generates a lot of EMI which must then be disappated in some fashion and taking the top off facilitates that disappation. But if the amp is creating the EMI in the first place, and its harmful to the signal, it seems to me as if the damage is already done.

If the EMI is externally produced it seems that having a non-ferrous case, including top, would be beneficial in keeping it out of the amp. I also don't understand the 'wave' concept, I can understand EM fields of changing intensity, but 'waves' which bounce back and forth off some surfaces but not others? Are you aware of any science which supports this?

Tvad, Audioaril, Tom, anyone - please help me to understand this.

By removing the cover you will have changed the mechanical mass of the entire chassis.Vibration and it effects on the circuitry will also have been changed. Vibration influences can greatly alter the spectral balance. The amp has been retuned within its own environment. Tom

I have not tried ERS paper, but one manufacturer that supplies a lexan cover instead of an aluminum one is DartZeel. Their amplifier, as you can see in a lot of literature, is supplied with a clear cover specifically for that reason.

Maybe shoot an email to DartZeel to explain this effect in more detail?

Also, while I believe that almost all components sound better with the aluminum cover off, this effect is especially prevalent in the DK amplifer where the difference is quite dramatic.

Tvad, I am telling you the amp sounds better with the aluminum cover off. In an industry where people use little pebbles, roller blocks, and expensive power cords I find it surprising that you should have difficulty accepting that the aluminum cover degrades the sound of the amp while a Lexan cover does not.

Also, while aluminum is non-magnetic it still will bounce more of the EMI then a Lexan cover will. If you shoot an electron into an aluminum plate the results are very different then if you shoot an electron into a Lexan plate.

Work in progress....My speakers don't really allow me to turn up the volume much past the 9 o'clock position with out involving the neighbors and I also noticed the lack of heat produced and decided to try something to see if it improved the performance. In the past my MC275 tube amp sounded ok at lower levels but really started performing at the higher volume levels. Anyway I have a sony cd with an adjustable output so I simply dropped the input signal and cranked up the DK to the between the 11 & 1 o'clock positiion to see if hopefully it works a little better. I think I may be on to something.....
Does anyone have any info on what the pots on the preamp board relate to? I remember reading something about the adjustablity of the input...
The meter is not as entertaining but I am thinking at this point that it sounds better.....

Tvad, What is needed is a magnetic cover - that will absorb those electro-magnetic waves and they won't just bounce about in the amp. If you don't believe in electro-magnetic waves or fields just look for the Aurora Borealis. Maybe there is a look alike in the amp that only appears in the dark. ROTFLMAO, but not at you. :-)

This is so far, the most polite discussion about DK Design Group products I have ever seen in the forums. This is a nice change for the better.

Art, when you say leave the amp on, do you mean on power or on standby?

This may be a dumb question but I believe tubes need biasing (dont know what that means though).

Anyway, do designs like DK and BAT and McIntosh offer a feature where the biasing is done automatically since I'm quite apprehensive of doing this myself. Unless someone here can convince me that it's easy and hassle free.

Thanks

One way to achieve the best sound and still have a cover for your DK is to have one made from Lexan. It is a clear material, so the cover will be see through, but it wont have the electro-magnetic bounce effect like the aluminum cover does. I think that DK really dropped the ball on this detail because really it sounds MUCH better with the cover off.

Audioari1,
I also have found that the amp sounds better with the cover off.Regards,Bob

Tvad, I am fairly certain that it is not due to the cooling effect because the amp doesn't get very hot in the first place. And it makes logical sense that the electromagnetic bounce effect is at play here. In any case, whatever you want to call it, the DK amplifier sounds substantially better with the top cover off, try it and see for yourself.

One tweak that I tried that makes a BIG difference is playing the amp with the cover off. When the cover is on, electromagnetic waves bounce off the metal and back into the amplifiers circuitry. When the cover is off, you will be surprised how much better it sounds.

Jomoinc, ERS cloth on the output wiring may help - I will may try that. The power cord makes a significant difference too. I was using a ZCable Cyclone for awhile which sounded VERY nice which it should since it cost more than the amp. I now use a ZCable black lightning which solidified the bass a little more and took that last bit of edge off the upper mids and lower treble which may have been tube glare in my system. I've also used SignalCables basic power cable on it which was ok but it didn't control the bass as well as the ZCable black lightning.

Sbayne, interesting especially considering the didgital metered display which may be a source of rfi interacting with the transformers.
On the inside rear panel, do you think the speaker output wiring proximity to the preamp tubes might cause any interactions?
Also stock power cord or? Mine did not come with the factory ac cord so I am needing to find something synergistic that moves the performance in the right direction.

I have to agree with Art it sounds much better when left on. Besides tube rolling (I use Mullards)I put ERS cloth around and on top of the transformers which helped flesh-out the midrange and opened the soundstage noticeably. Check out www.Tweekgeek.com for the ERS cloth.

I found that tube rolling made a big difference, but the choice of tube preference depended on equipment and also personal preference in sound.

Also, I found that leaving it on virtually all the time made a big difference. It takes many hours to warm up. To play it in the morning turn it on in the evening.

Art