Dx Blame MKIII Supercharged will soon be released

[destroyer X]

But when we increase board size we have problems to install two big boards inside an enclosure.... this worries me.

Go ahead.

regards,

Carlos

[meanman1964]

Yes I'm shure it's only 28mm differents not a big deal
That's why I ask people what they want

[alex mm]

Hi Meanman ,
I have adjust to correct size , 265 mm X 115 mm
Alex.

[CaféNoir]

I am not sure about the bigger boards with L-brackets.
As Mr. Carlos said, it means less space to install in a standard enclosure, which will have quite big transformers inside as well. You lose space of the transistors, and of the brackets thickness.
Also, I think the first slimmer version is more versatile if one wants to install the boards vertically, attached directly to the heatsinks, allowing a compact solution.
Not to mention the loss of heat transfer induced by brackets.

[meanman1964]

It all depends what the people at my groupsbuy wants.When you build a high power amp you don't instal everything in a small case.If they want the smaller boards it's OK by me.Alex can you send me the files of both corrected boards regarding the 390 Ohm resistor?

[CaféNoir]

Originally Posted by meanman1964

It all depends what the people at my groupsbuy wants.When you build a high power amp you don't instal everything in a small case.If they want the smaller boards it's OK by me.

I will make some 3D models of case layouts, and see what comes up

[destroyer X]

Go ahead.

C'a marche!

regards,

Carlos

[CaféNoir]

Here are some some basic 3D layout models to investigate boards dimensions.
I have used a fairly standard Hifi2000 pesante dissipante 3U for the illustration. The reason I chose Hifi2000 is that these have common dimensions, and are widely available, so this makes a good reference. I added PSU caps and transistors for cosmetics.

This first layout features the slim board without the L-brackets. There is room for a 500VA transformer of standard diameter.


Next features the large board with L-brackets. Space is considerably reduced. The 500VA transformer does not fit.


One solution is to go for dual smaller transformers (around 225VA), which fit very tightly between the boards. But there is very little flexibility on the size of the transformers. For instance, I like to use shielded transformers, which adds to the diameter. Not possible here.



Next, let's investigate the vertical mounting. Vertical mounting is managable with the slim board, with a little bending of the leads of the transistors.



Large boards will hardly fit in the 3U case. A 4U case will be needed, which will lead to sub-optimal space management.

So, my take on this is that the L-bracket mounting has more disadvantages than advantages in this application.

[a.wayne]

Originally Posted by alex mm

Hi Meanman ,
I have adjust to correct size , 265 mm X 115 mm
Alex.

Sweeet ...alex ..


Cafe Noir , I dont like the last layout , the vertical mounting have the outputs at the top, this will have issues with cooling IMO. Guys this is a big amp , the others look fine and most likely this amplifier might require 2 chassis and or for sure large custom case . Please do not compromise the boards to try and fit in some kind of micky mouse cage , this is a big bwoy amp, please keep it as such ....

[a.wayne]

This is a 20 output device amp, i cant see one wanting to use less than 2 /500 va trannies or one 1 Kw tranny ...