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
It’s getting to the point where a person can’t even share a noticeable change in his/her system without everyone arguing about it. Pretty pathetic. We should all be happy we aren’t 6’ under and still have the ability to listen to music. I think next time I change tubes on my pre I’ll try this. Why not? Who gives a rats -$&? Thanks for sharing. 
At the end of the day it really is ok to like what you like based on whatever criteria you decide to assign. It's so ridiculous to try to convince someone else you're finding joy in something for all the right reasons or defending yourself that your reasons are solid enough.  What a waste.
btw, djones-    About what gravity actually affects (more than just galaxies), you'll notice the name of this famous, still held as valid, theory, includes the word, "Universal":     https://www.physicsclassroom.com/class/circles/Lesson-3/Newton-s-Law-of-Universal-Gravitation     Did you sleep through that Jr High, Science class?
my darTZeel NHB-468 mono blocks are a vertical design, with Plexiglas sides. you can look in and view the beautiful circuitry.

https://systems.audiogon.com/systems/615#&gid=1&pid=12

my previous amplifier, the darTZeel NHB-108 stereo amplifier, had a plexiglas top. it has similarly elegant circuitry and build quality.

the designer found that the amps sounded better that way. EMI/RFI effects were reduced.....not fully enclosed with metal sides.

can’t say every amplifier would get similar benefit. the darTZeel has a very minimalist design (low parts count in the signal path) and zero global feedback. very pure and quiet. so the little chassis design features matter.

YMMV and just my 2 cents....
The tops of both my Transnova 9505 (Bass amp) and BAT VK-D5, have been in a drawer, for going on two decades.      Can’t fit the top on the amp anyway, because of the power supply mods, which included some big capacitors.      At least, not without 3/8" stand-offs, anyway.      The CDP has six tubes in it, which I like to keep on the cooler side.      Just means, I have to clean the LASER, more frequently.     Everything’s separated, by some old-school,Texas Instruments RFI/EMI blocking, metal sheeting, lining every rack shelf (yep- grounded).      Some stuff Michael Percy used to sell.
Mike I agree...same way with my amps. I can easily lift the lids off on both..and hear a  difference . Same with my breaker box in my room with an audience to hear the change while doing so. With all the shielding used to keep RFI and EMI at bay maybe we are containing the RFI and EMI and allowing the pollution to remix with the intended signal..Same for vibration control systems. Without a clear and directed path out the self generated component noise will never leave, it will only be refilled and replaced by more of the same. Tom
A piece of metal, or whatever, covering the amplifier is hardly the universe. But it may be, if we all just wish hard enough.
rodman99999
Newton's Universal law of gravitation can get us to the moon, Mars and points beyond. It works very well on small scales like solar systems and galaxies, though it isn't as accurate on that scale. The only problem is on large scales like a Universe it's wrong which is why our working theory of gravitation is Einstein's theory of general relativity with the cosmological constant. We discovered that Newton's Universal Law wasn't really universal. 

https://wtamu.edu/~cbaird/sq/mobile/2015/06/09/does-the-influence-of-gravity-extend-out-forever/
Is this mission to Mars or using an amp without a cover?...apparently they are one in the same.


Same with my breaker box in my room with an audience to hear the change while doing so
 So you're saying you take the dead door off your panel box and your stereo sounds better? Interesting, and you've had a group of people hear this as well? 
I didn't bring up Newton and universes but I wasn't going to let misinformation slide.
Yes I posted about this years ago..its somewhere in my history and history repeats itself everyday.. Interfering Energy...it can be in many forms and types. That is what Mike is hearing when he removes the panels on his amps just as I do on my amps..Some of it is EMI and some of it is shear wave interference traveling from panel to panel back into the system. Tom
What part of, "THEORY", don’t you understand?     People have argued theory, since the beginning of what’s called, "Science".    According to the scientist(s), involved in the penning, of the article I submitted, "TODAY (my emphasis), Newton’s law of universal gravitation is a widely accepted theory.     It guides the efforts of scientists in their study of planetary orbits.      Knowing that all objects exert gravitational influences on each other, the small perturbations in a planet’s elliptical motion can be easily explained.      As the planet Jupiter approaches the planet Saturn in its orbit, it tends to deviate from its otherwise smooth path; this deviation, or perturbation, is easily explained when considering the effect of the gravitational pull between Saturn and Jupiter.      Newton’s comparison of the acceleration of the apple to that of the moon led to a surprisingly simple conclusion about the nature of gravity that is woven into the entire universe.     All objects attract each other with a force that is directly proportional to the product of their masses and inversely proportional to their distance of separation." (end quote)     That’s NOT just my opinion.      That there are other theories, CAN’T prove anything, categorically (even Einstein’s).       The Cosmological Constant, took into account, something that (theoretically) fills the universe.       You’re just twisting in the wind!     I’ll leave the ubiquitous, "last word", to you.
I find mixed results.  In another time, I pushed equipment hard.  Heat was problematic.  Some equipment had been perminately covers disassembled to facilitate opening.  How many of us remember the days fo small fans?  
It is not a big event in human history and a big act of faith to imagine that a slight modification can change the sound in a room....(it is not necessary to invoke Quantum mechanics or Relativity)

If you put 3/8 inch copper cones on 2 strategic locations on a wall you will modify the acoustical image in an audible way...But you will hear it only if your audio system is not too noisy, because perceiving a change is also linked to the way an audio system is already minimally rightly embedded in the one, second or third embeddings dimensions (mechanical, electrical, acoustical)...

If you put off some cover from an amplifier, is it then difficult to imagine a possible felt change in listening? Why not?

Forgetting peculiar electronic designs which are the basis of each part of possible gear, in my experience, what makes the S.Q of any audio system (located in one of the three rungs scale of quality/price ratio, never mind which one) is the way the audio gear is grounded and tuned in the 3 embeddings dimensions: mechanical, electrical, and acoustical....

All arguing about tweaks are only reflections, unbeknownst to those arguing most of the times, revolving around the controlled or non controlled many parameters of these dimensions...

This is my experience, always suggesting and speaking of placebos effects for that is only showing ignorance of what are placebo effects in a medical context and what audio is all about, if by audio we speak about something different than strictly electronic engineering design....

The human ear is designed structurally with a very refine abilities to perceive and to distinguish S.Q. at a level only known by recent science research....

https://phys.org/news/2013-02-human-fourier-uncertainty-principle.html

«In the tribunal of living perception Creative imagination is a better judge than dogmatic reason»- Groucho Marx studying Goethe
The reason for the perturbations in the orbit are because the mass of planets and the sun warp spacetime, what is happening is they are moving through a curvature of spacetime. On these small scales Einstein’s theory of warping space behaves like Newtonian gravitational pull though Einstein’s is more accurate. Don't have a stroke over it. Yes they are scientific theories and someday one may replace Einstein's theory just as his replaced Newtons. It doesn't mean Newton's doesn't work good enough to get us to planets.
Yea, what he said ^ I think I'll suspend all my equipment in zero gravity & see if I hear a difference, if I can keep it all connected while its floating around.
"Ah! Ah! Creative imagination what is that?" mocks the children in the school yard...

"Filling the blanks in some children’s pattern drawings" for example, says the teacher..... :)

Good night to all....



Just fyi; I never said I believe in any particular theory mentioned.      Just that, WE DON’T KNOW ANYTHING, for CERTAIN.      Without knowing, SPECIFICALLY, what is affecting what, regardless of the phenomena being examined/explained, "measurements" can only point in a direction and lend credence (or- not), to a theory.     That applies to Home Audio, as well as, the rest of the universe.       More a disclaimer, than a, "last word".
Not exactly sure what Huge means?  What areas sounded better?  By huge twice as good?  Please let us know.  I am not doubting you just trying to understand what and where.

Why don't manufacturers just make it right the first time - that is easy, it adds to the cost so the product would have to cost $400 more at cost and nobody sell at cost.

Back in the day many manufacturers used heavy copper chassis designs.  I use a copper plate in my components but there are other metals that also sound very good.  My Audiomeca Mephisto transport uses very thin metal but it sounds excellent versus some the the other every heavy chassis transports I have.  So who knows.


"...and you've had a group of people hear this as well?"
Voices? What voices?

The op makes the case that removing the top panel of an electronic component may improve it’s sound quality. It is also possible that doing so will degrade same, in particular if the metal chassis of the component is designed such that the top panel braces the sides (just as the braces inside speaker & sub enclosures prevent the enclosure walls from producing sound by flexing). The late Gary Dodd installed his circuits into wooden chassis; whether or not to avoid the resonances of metal I don’t know.

Old school audiophiles have long applied damping materials to the chassis of electronics to reduce resonance. Michael Percy sells EAR IsoDamp SD, made to reduce the SPL produced by the large machinery in industry. 3M makes a similar product. Real old-timers used the sound deadening mats made for automobiles, Dynamat.

In the meanwhile....use some nice, quiet computer fans.

Y'all note periodically how your amps of whatever format create enough BTUs' to act like space heaters....

I've noted that the backs of the magnets on my speakers can get hot to the touch.  Now, I realize that I ''push' voice coils into parameters that the designer(s) may not have had in mind.  Therefore, I actually put an index finger on them to ensure I don''t fry them.

Ever touch a circuit breaker with a high load in a panel?  One of the 1st things that breakers exhibit before they 'pop' is heat.

I've been in a situation where we ran fans on open breaker panels to keep them from frying in summer heat due to the demands placed on them.  It helped long enough to get about to tell the 'abusers' to back off on demand.  It was that, or the whole system would go down....and stay there.

EM? Vibration? Huh?!

Anything with a current running through it is warming up.

Simple physics.
asvjerry,

"...to keep them from frying in summer heat due to the demands placed on them."
They will always heat up before being done, but isn't that the whole purpose? Does summer heat contribute that much that it would break?
labtec
 Why do you need your eyes to listen to music?
It isn't clear why you'd ask that question. I often listen to music with eyes closed.
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?
It isn't clear why you'd ask that question. I have no issue with people listening with eyes closed.
You realize that whatever you did to reach your subjective "conclusions" with your eyes open...you can do with your eyes closed...right???
Yes, that's fairly obvious. Thank you.
Are you saying that the placebo effect doesn't exist? Confirmation bias?
 Do your questions have any point? If so, why don't you state your case?


I might try this on my Parasound A21.  Either top off or maybe a Plexiglass top instead.  I must admit that part of the reason I bought it is that I thought the innards are beautiful — I figured something so beautiful must make beautiful sound.  To have people look in it while it produces nice sounds would just add to the joy!  Thanks for the suggestion.
Microprocessors in electronic devices, especially all the ones in CD and Blu Ray players like Oppo, generate beaucoup RFI. So, removing the top metal cover or using a plexiglass cover instead allows the offending photons to exist the component rather than get trapped inside where they can do a number on the signal in wires and fuses. Problem solved! 🤗
Without responding to anyone directly, but reading through the comments...

* the bass actually has more slam and is more articulate/authentic sounding sans diver weight


* the resultant sound can be likened to previously the microphone/s were wrapped in a towel which muffled the entire 3D soundscape


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

* The entire chassis is made from the same material, so why would the lid be the big offender

* I am going to get a central air conditioning filter which SHOULD keep dust and mites out while letting hot air escape

* several months ago a friend brought over his laptop which he uses to make live recordings, so it’s not just any old laptop. First we listened through my CD player. When he hit play on his laptop my jaw dropped. After a few notes, I looked at him with jaw dropped.The expression my face said it all, "one giant step" for music playback. BUT, I have 1000+ CDs and am not inclined to transition from them. BUT removing THIS lid brought me a lot closer to the laptop experience

Should go without saying, but YMMV
* The entire chassis is made from the same material, so why would the lid be the big offender
Try removing the entire chassis. See what I did there?
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.
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.
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.
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?)
 
"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.

Heat is work and work is heat (ΔU=q+w) perhaps that might have something to do with the perceived better sound?

I’d assume that no top/sides would let heat dissipate better.

Thermodynamics has to be some sort of real factor in preformance?

Vibration(s) surely that can't help gear and I think why it's often proffered not to put ones conponenets between speakers if possible. My stuff isn't between the speakers (good?) but is on heavy wire shelving (bad?) due to limited space in a walk in pantry. 
Real audiophiles always go topless so everyone can see their expensive circuits. 
I tend to be a little skeptical about some of these pixie dust sounding tweaks people come up with.  But that said, I had some money to burn so I purchased some audiophile grade power cords.  I fully expected to hear no improvement. That was my expectation. I was pleasantly surprised to find that there was an improvement, and my 65 year old ears with tinnitus could hear it. I then switched out the fuses in my Linn Unidisk player and Lyngdorf integrated with SR Blue fuses. The improvement was I would say amazing but I know I'll get jumped on so I'll say more than just a pleasant surprise.  So, I am not going to say that just because it sounds crazy to me (like Millercarbon's magic potion Perfect Path, that there's not something to it. I am a believer.
"...my 65 year old ears with tinnitus could hear it."
Not related to this thread, but, over time, I noticed a number of members here mentioning their tinnitus. Is having above-average music equipment a risk for tinnitus? Overuse of sorts?
glupson....sorry for the late reply....

The example was circuit breaker panels in 100+ ambient summer temps outdoors, being pushed beyond their amperage ratings....the fans simply bought some time....

But the same is true for amps....the 1st 'US Festival' in CA years ago had them going thru amps like popcorn in similar temps....

This directly relates as to why some 'gamers' who 'overclock' their CPU's will resort to liquid cooling in their 'puters'.  Overclocking is like running nitromethane in your Toyota.

if you don't 'prep' for it, you Will break your Toy. ;)

I run fans because I know that even 'mild excess' can have a consequence.

Hey y'all.... take the covers off...it's your stuff....*shrug*

Out of warranty, I hope....

It only works for Amps...heat is negligible for anything else.....

You don't think they test their wares with covers on?
It’s unfortunate that the the OP intro (in this instance ME) can’t be edited. I had several edits that would have helped, but NOoooooooooooo

Anyway, a correction: the top has SOME slats (1+" ) across the back, clearly not enough, but even if there was 2,3 or more times the amount doesn’t mean that would produce the benefits removing the top did

Last night I listened to James Taylor Gorilla album/CD. I even owned the album way back when. It’s one of my fav songs, meaning Ive listened to it literally hundreds of times. The whole album sounded new to me last night. This morning I removed the Cubes without any loss of musicality and replayed a few cuts, including Gorilla. No negative result to my ears, and quite possibly another lifting of the veil


hth
This thread is somewhat confusing. I was under the impression that the two advantages of class D over other classes was efficiency and cool running (really one leads to the other). How much heat does your amp build up that going "topless" can create a sonic difference?
Jetter
I have owned PS Audio  (M700s and GCC 250, which I still use in my TV system), W4S both stereo and MC 250/500, Emerald Physics monos, Audio Alchemy DPA-1- all class D. I never thought to go topless with them

NONE of them generated anywhere near this level of heat
I don't have the answer as to why, but pretty sure removing the top helped immeasurably, not only to the life of the modules and related parts, but most certainly to vastly improved sound

YMMV