The Very Best Amplifier I Have Ever Heard!!!!

just popped in to my mind

I wonder how it works when a big company ( name big any one you like Sony ? Technics ? Sansui ? ) so i presume that when these people design amplifier that we don't talk about Jim or Ken ...it should be a team of engineers that will study every aspect of a concept

So i wonder .... why any of them never ended up with such results ?

If the NVA founder actually noticed some difference in sound using a plastic enclosure especially made with absolutely no screws and everything inside is made with glue then the next thing that comes in mind is that the all team of engineers of Sony for example are probably stupid since they never found the effect of metal screws in sound ....

Does it make any sense ?

then again i take it as a fact that any vibrations should have some impact in the operation of an electronic circuit ....So inside this forum there is a load of respected scientists and please .... someone might tell us or describe how this impact will effect our sound or even better describe this with technical or understandable terms ...

Example ...

metal screws will reduce the bandwidth of your amplifier by 2db at the range of 25-26 KHZ ... this is an understandable example .....
 
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.................If the NVA founder actually noticed some difference in sound using a plastic enclosure especially made with absolutely no screws and everything inside is made with glue then the next thing that comes in mind is that the all team of engineers of Sony for example are probably stupid since they never found the effect of metal screws in sound ....

Does it make any sense ?.....
I have stated publicly that every amp I have built sounds worse when mounted in a steel chassis, compared to no chassis.
I have also stated publicly that no amplifier that I have ever built sounded better in an aluminium chassis compared to no chassis.
To the best of my ability, I cannot make a metal chassis Power Amplifier better than an uncased Power Amplifier.

Compare, no chassis (air) to plastic chassis/case. I wonder what the difference would be?

.
 
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I have stated publicly that every amp I have built sounds worse when mounted in a steel chassis, compared to no chassis.
I have also stated publicly that no amplifier that I have ever built sounded better in an aluminium chassis compared to no chassis.
To the best of my ability, I cannot make a metal chassis Power Amplifier better than an uncased Power Amplifier.

Compare, no chassis (air) to plastic chassis/case. I wonder what the difference would be?

.

Really though? AndrewT you are a technical person, how do you justify this?
 
www.hifisonix.com
Joined 2003
Paid Member
Jcx or jneutron did some calcs a few month back that showed you needed significant currents in the proximity of ferrous material to cause problems. Steel provides a great shield against EM radiation, and in the case of aluminum/aluminium you get screening from electrostatic coupling provided of course in both cases you take care of grounding etc. iI may be that where there is a perception that an amp sounds worse in an enclosure, there are other issues that are at play eg grounding, cable dressing/routing etc.
 
I have stated publicly that every amp I have built sounds worse when mounted in a steel chassis, compared to no chassis.
I have also stated publicly that no amplifier that I have ever built sounded better in an aluminium chassis compared to no chassis.
To the best of my ability, I cannot make a metal chassis Power Amplifier better than an uncased Power Amplifier.

Compare, no chassis (air) to plastic chassis/case. I wonder what the difference would be?

.


ok ... I like that Andrew ... can you define that and explain it somehow ?
Is there anything we can measure to understand what and why

I take i as a fact that you placed your opinion based on your personal experience I also take as fact that when you say """ every amp I have built sounds worse when mounted in a steel chassis """ but can you explain why ?

Kind regards
Sakis
 
we don't talk about Jim or Ken

I still have an article from the first half of the '90s somewhere on the Pioneer exclusive M8 model, with names.
(but as a team, would be very Un-Japanese and unmodest to place themselves above the only company they'll work for their entire active life)
The M7 is all about solid copper, everything covered and surrounded by it.
 
Disabled Account
Joined 2006
Jcx or jneutron did some calcs a few month back that showed you needed significant currents in the proximity of ferrous material to cause problems. Steel provides a great shield against EM radiation, and in the case of aluminum/aluminium you get screening from electrostatic coupling provided of course in both cases you take care of grounding etc. iI may be that where there is a perception that an amp sounds worse in an enclosure, there are other issues that are at play eg grounding, cable dressing/routing etc.

In the days of Marantz CD63 I noticed a difference in sound between some models. Upon some investigating I found that the only difference between two models was that one had the inside of the casing coperplated as well as the small shield casing around the discrete opamp section. The rest was identical. The difference was crearly audible.
Ill probably need a Molecular scientist to explain this one to me..........

Ps I forgot the copperplated version also had copper screws.
 
Golmund clone

Niko, 3pair output stage.
What output bias current, what output quiescent dissipation, what temperature for Tj, Tc, Ts & Ta?

with R20 390Ω =100-110 ma
with R20 360Ω =50-60 ma
Rail +/- 70V
100 ma = 5 W quiescent dissipation per device
50 ma = 2.5 W quiescent dissipation per device
Heatsink SK56 Tj, Tc, Ts & Ta?
See:
http://products.semelab-tt.com/pdf/ApplicationNoteAlfet.pdf
Take a calculator you are good with it.
 
Sakis I understand that the NVA is hardwired, no pc board or circuit board. This would make a difference in to the sound, the quality and material of the board also affects the sound when a board is used.

+1000 i agree but here the question is about the enclosure

i wonder how my latest product will sound since its made with the bottom part of the enclosure from aluminum ( helps cooling a bit ) while the top is made of iron ....

DSC00445.JPG


DSC00449.JPG
 
but here the question is about the enclosure

I think there will be no big issue with metal casing if the main source of radiation (transformer) is outside of the enclosure.

But your toroidal transformer tends to have its magnetic flux confined to its core, so more safe than EI transformer.

I prefer to shield the sensitive parts of the amplifier, from RCA to input stage, because the shield material required is few. If necessary the cable is as short as possible.
 
pcb ver 2

I have finished the new version of pcb :

1. The 2n5565 has been modified so that if you have a dip or soic version (LSK389A), you can still use it here.
2. The T3/4, T5/6, T7/8, T9/10 transsistors pairs are re-oriented that they can be stuck to a metal strip for better thermal coupling.
3. The additional T23, T24 can be implemented by using a small piggy board. Please see the attach for new schematic


I think someone mentioned using IRFP240/9240 pair by adding a Vbe. Someone please suggest one so I might included this too?


Can someone please tell me how to attach more than 1 files to a post?
Although I had checked, hope someone can check my work again.

I had order of 10pairs at hand. I would start a GB if anyone is interest.


BP
 

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