2. amps-preamps
  3. 156499-2546

Who's Gone Topless?

The idea of this goes back decades. Amps and preamps (for the most part) are designed on chassis free breadboards, then voiced, THEN are packaged inside a chassis, which can be the weakest link to hearing what the designer intended. In most cases the chassis sidewalls and bottom are essential, but the top?


First off, beware that doing so will likely affect your mfg warranty, but, if you live in a pet-free, child-free home, then the benefits can more than offset concerns about something getting in that could harm the components. Case in point my Ric Schultz Class D EVS 1200, dual mono IcePower 120as2 modules. HOWEVER, unlike others using the same or similar modules, Ric then sprinkles many decades of modifying pixie dust all around them which are mounted inside an understated (sans bling) Italian sourced chassis.

When I ordered mine it was mandatory to purchase 2 Cubes ($200) which are to be butted up against each board, requiring the owner to remove the top. After doing so, I was anxious to put it in my rack so I could properly isolate it from bad vibes, when I should have listened with and without the Cubes and top.


Ric is also a proponent of weighing down components, but due to the unnecessarily large chassis, it barely fit in my rack, but I had a 5 pound divers belt lead weight that I squeezed in. Now, because RIc chose to put the mute toggles on the back I placed the amp on the first shelf from the rack's top (but out of sight out of mind: I never mute it when done listening), upon which was my CD player/Transport, which I raised up to provide ~ 2" of air space above the top of the 1200 and the bottom shelf of the player. Even though the rack is open on all sides with plenty of air space all around the rack, the amp ran warm

Fast Forward to yesterday. I was listening to Leonard Cohen Essential songs, mostly instrumentally sparse. I removed the weight; and found the music much more open sounding. Encouraged, I FINALLY removed the top. Honestly, I was not prepared for how HUGE doing so could be. It was like the music went from a confined space to an open air 3 dimensional venue. This is so amazing that I am going to get a handle on it via different music before removing the Cubes. Oh, and the amp is now cool as can be. 


So, if interested, stay tuned
tweak1
Post removed 
djones51
4,947 posts
 

Really? Why? Could it be, because you don't understand the difference between someone relating their individual personal experience and the release of a statistically valid peer reviewed article in Nature?
 I understand the difference between unsubstantiated subjective claims and verifiable objective phenomena.  

I see. So you're here for all the.... lack of information. You would be content to come here and read page after page of vague useless pabulum.

I'm here for real information not vague useless nonsense about removing case covers and hearing A HUGE improvement in my stereo. If one says I believe there was a slight improvement then it could fly under the radar but to claim HUGE improvements should be fairly easy to quantify. Record a song with top on then off,  Post a link the recording, HUGE improvements should be easily heard on my laptop. 
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cleeds
5,662 posts
 
djones51
I'm here for real information not vague useless nonsense about removing case covers ...
This is a hobbyist's group, so it seems fair to me that that people are allowed to post the results of what they hear. Why should anyone be obligated to conduct tests to satisfy you? After all, you're free to conduct your own tests.
djones51
4,947 posts
 
They can post what they hear and I can post perhaps you heard it for a different reason. No one is obligated to test anything. I've had the top off amps before can't  say it affected the sound, is that my test? 
petg60
1,486 posts
 
Hi,
equipment cases do have a negative effect if not designed properly. Besides that some carry ferrous particles for a reason or not (easy to realise when placing a magnet on them). If too resonant, chassis resonance may be reduced by something like a sheet of EAR Soundcoat or similar.
Vibration control is another topic and more elaborate to deal with.
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