2. amps-preamps
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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
mikelavigne
2,243 posts
 
as far as resonance issues, in addition to the plexiglas sides on my darTZeel NHB-468 mono blocks, the power supply of each amp is suspended inside the chassis. for transport there are screws which get removed and replaced by covers when it’s in place.

i once forgot to remove those transport screws, and i could hear the congestion in the mid range and checked my whole system for something lose or wrong before realizing i had forgot to remove those transport screws.

and if that is not enough for optimization (it’s not, at the tip top of the food chain), both of my mono blocks sit on active Taiko Tana shelves with outboard power supplies.

https://systems.audiogon.com/systems/615

everything does matter.
djones51
4,947 posts
 
Just that, WE DON’T KNOW ANYTHING, for CERTAIN.  
Getting to philosophical for me. 

From day 1 owning the EVS 1200 I said the chassis is unnecessarily large, (and the lid has no vents)

I guess it could have  been running hot.
geoffkait's avatar
geoffkait
23,365 posts
 
In Mapleshade’s Pierre Spray’s “laboratory” downtown DC where I demo’d my Nimbus iso platform back in ‘96 all electronics were sans covers (as we say in the biz). Everything was connected together with those really cool 54 ga interconnects and teeny tiny speaker cables. I distinctly recall we tried just barely damping the top plate of the Nimbus with an Indian silk scarf and it degraded the sound. Just thought I’d mention that. Yes, I said 54 ga.
jpwarren58
719 posts
 
Dust in the Wind and by far one of the worst songs ever recorded or written. 
Doesn't this discussion assume absolute ear equality? One man's tweak is another's fleeting waste of time.
As to dust---a pox on it and it's kin.

(Hey there is a good name for Miller's book...One Man's Tweak...will he use his pencil name?)
 
glupson
7,842 posts
 
"Dust in the Wind and by far one of the worst songs ever recorded or written."
And most irritating. Osibisa's Sunshine Day may take that title, though.

I heard about some study (at least that is how they described it) that found out the best way to get the irritating song that does not want to get out of your head out of your head. It is whistling Girl from Ipanema backwards.

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