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
tweak1 OP
3,559 posts
 
@glupson4 what was your experience placing a ac filter in place of the metal top plate?


To the person who mentioned that chassis are made/built specifically for an amp, this is not one of those. While it was ordered from Italy, it is not machined from billet to snugly fit the parts

I got a 3M filter but it doesn’t pass the heat as much as I would like and after being on for awhile, it smelled from a reaction to the heat. I need to try a plain fiberglass filter, which I know has considerably more air space. Worst case I only put the filter on at night


Back to what Im hearing: one of my torture cds is Jennifer Nettles Playing With Fire. Some of the cuts are downright brutal, to listen to, that is until last night. Though the terrible cuts still sounded bad, her voice and the instruments did a much better job of separating, which allows subtle ques to be easily heard.

So far, every disc Ive played has brought me much closer to the actual recording event. For those who are motivated, feel free to add your comments, pro or con


Geoff, As you know I have New Dark Matter in my Oppo tray and it sits on your springs, but if you know that removing its top cover will release a bunch of nasty stuff scattering around inside, I will do that today. Emailing me would be faster, but you could reply in both places so others might follow suit
glupson
7,842 posts
 
tweak1,
@glupson4 what was your experience placing a ac filter in place of the metal top plate?
I have no experience with that. I thought your reference to filter was to use it what it was designed for, in an air conditioning system.

However, now when I have general idea about it, how do you install it without whatever you need for instalation potentially affecting the sound? Some wood contraption? Plastic? Suspended from the ceiling with silk ropes? Why only the top plate? 
lwal22's avatar
lwal22
76 posts
 
Perhaps verification misses the simple and to me, most salient point.  Music and any other sound is perceived.  Not measured, verified or quantified when actually intended as an experience, rather than an exercise.  So... if the OP perceives a huge improvement, and shares why he thinks he achieved it, there is no argument.  None.
It is up to us to decide if we’d like to test, for our own enjoyment, his path to that change in perception.  Either you like it better or not.  
The validity of the OP’s opinion as to why, and how much change there has been, is not anyone else’s place to confront.  
I like to enjoy a bit of Cannabis chocolate with my evenings playlist.  Expands the soundstage.  Prove me wrong.

‘Listen to your music, not your system’ was the best advice I’ve received on Audiogon, to this day.
geoffkait's avatar
geoffkait
23,365 posts
 
lwal22
I like to enjoy a bit of Cannabis chocolate with my evenings playlist. Expands the soundstage.

>>>>>>But is it expanding the soundstage or your mind? 😳
tweak1 OP
3,559 posts
 
Yesterday afternoon I took the cover off my 105


Nothing like the crazy opening up and improved SQ that removing the lid and Cubes did


BUT micro-details are now evident. Examples; when a snare is being brushed, and the handle is used to gently tap the rim and skin, I actually heard the skin vibrate!, or when a singer starts to sing in a low voice, the first syllable is more easy heard and understood, and more separation of the instruments/singers

As always YMMV


hth
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