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

Showing 4 responses by millercarbon

millercarbon's avatar
millercarbon
12,531 posts
 
Whatever. Different subject. Point is, the OP heard it. The question of why, of what exactly is responsible or the cause, is a completely separate issue from the fact a difference is heard. 

djones is not saying prove to me its vibration control and not something else going on. djones is saying prove to me you heard a difference. Nobody can do that. How would they? Why would they even try? Least of all to him?!
millercarbon's avatar
millercarbon
12,531 posts
 
I’m here for real information not vague useless nonsense about removing case covers and hearing A HUGE improvement in my stereo.


Not thinking it through again. Do you even read what’s written? Or is that too inconvenient in your rush to deny and deride? Nobody said they heard a huge improvement in your stereo. They heard it in theirs. This is information. Good solid useful information. Which you then mock and deride. Because, reasons.

You require everyone prove it. Prove what? Their experience! Prove it to who? To you! But you have a record of being in denial of other people’s experience. So why would they waste their time? 

The truth is people are lucky to have a place to come and learn. What do people learn? That changes make a difference, we can learn to hear them, and over time use this to improve our systems. You come along and say, "Prove it!" 

No, djones, you prove it. You prove how it is that your constant denial has any value here whatsoever. You prove it. Until you can come back to us with a statistically valid peer reviewed double blind study showing the relevance of statistically valid peer reviewed double blind studies!
millercarbon's avatar
millercarbon
12,531 posts
 
Interesting subject. I'm from the "everything makes a difference" camp...be that good or bad; but I do wonder about this. In particular, over the years I have seen certain preamps with acrylic tops installed to show the pretty innards. A Klyne pre comes to mind; and I've wondered if that incidentally has any audible effect on the way that it sounds.


Of course it does. The reason is vibration control. The minute you start running a music signal through anything the whole thing starts vibrating. Its not only speakers, turntables- everything. This is why its so wrong to think of vibration control as isolation. Its not about isolation. Even somehow perfectly isolated you still have the problem of vibration generated internally within the component itself. 

There are all different ways of controlling vibration. One is with mass. Adding dive weights literally results in a more tightly controlled presentation with greater bottom end foundation. You could call it weightier. If you wanted to be clever. Or accurate. Opening the component up by removing the top will, uh, open up the sound. Just like the OP heard. 

This is not by the way conjecture. I've actually tried all this stuff. Heck you can see the blue dive weights on top of the Oppo player in my system. 
https://systems.audiogon.com/systems/8367 

They're there not because they're perfect, but because they're good enough. Its digital. Who cares? Never gonna sound good anyway. Good enough's good enough.

Long before the dive weights were on the Oppo they were on the Aronov.
https://www.theanalogdept.com/c_miller.htm
Notice the top and sides of the Aronov are removed. I listened to it both ways, it sounded better this way. Notice they are not on the Melody.

That's because its about vibration control. Like tuning a violin, no one can tell you what to do by remote control. Of course it will sound different with an acrylic top compared to metal. Or wood- or none. Which is better? You just have to try it, listen, adjust, listen, compare, and listen and tweak and listen some more. There is no substitute. 




millercarbon's avatar
millercarbon
12,531 posts
 
djones, not thinking things through again:
It puzzles me why anyone declares HUGE changes without taking into account human biases.

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?

Now "I think there was a slight improvement but I have no way to verify" , elicits no response from me.

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. 

Well that does explain a lot. Yes it certainly does. If only there were some way to verify....
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