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
glupson
7,842 posts
 
theaudiotweak,

Then you must know that electric filter does not make a house virtually dust free.

Dust mites are another topic. They like to get warm in an amplifier. Once the cover is off, they just flock there.
labtec
189 posts
 
@cleeds Why do you need your eyes to listen to music?  Why are you so against people confirming if they HEAR a difference by just using their ears and not knowing what changed ahead of time?

You realize that whatever you did to reach your subjective "conclusions" with your eyes open...you can do with your eyes closed...right???

Are you saying that the placebo effect doesn't exist?  Confirmation bias?  

Do any claims that have no justification in physics or engineering require no extra measures of verification? 

Or do you just believe anything you read online and hide behind virtue signaling logic about "it's not my place to say anything".

It's clueless, gullible, and non science believing people that spawn snake oil salesmen in countless industries. You merely have to read it on a forum to believe it. Plus, you'll even run to your keyboard to defend the person if anyone asks for more scientific verification.
rodman99999
5,983 posts
 
There’s no, "scientific verification", for 90 to 95% of what exists, in our universe.      We know it’s there, but- we can’t see it, touch it, taste it, hear it or smell it.      Yet; we know it’s there, because IT’S gravity is holding THIS universe, together (theoretically).      OH, YEAH: and something else (perhaps), that fits the same description, is also pushing/pulling it apart/accelerating it’s expansion (theoretically).
cheeg's avatar
cheeg
241 posts
 
Without getting into the rollicking fun of debating who should be responsible for double blind testing of observations posted on Agon, I thought someone should point out another possible reason why removing the top could make a sonic difference: temperature.  If the box doesn't let enough air circulate, the components may be running warm, or may undergo thermal fluctuations that audibly affect the signal. 
sgordon1
407 posts
 
Periodically, I turn off the topless power amp.

I cover it with a t-shirt while vacuuming the carpet,
and leave it there for a few minutes, before removing.

I use a small carbon fiber brush (with power cord disconnected)
moistened with anti-static spray to hit the inside
of the amp, as it sits below a ceiling vent for heat/a.c.
A minute well spent.
More to discover