Aleph 5 parts and physical layout.

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi,

I've been meaning to build two aleph 5 monoblocks for some while now, but progress has been slow during summer. A cold norwegian summer will change this. :) I've almost finished deciding what components to use.

This is what I plan to use for one monoblock:
500VA toroid with 30V secondaries from reichelt
4x39000uF/50V panasonic tha series from digikey
irfp240 from reichelt
1% resistors from reichelt.
The rest of the components will also be bought from reichelt.

Heatsinks are already bought from conradheatsinks. Exellent quality and speedy service.

I will be using Kristijan's pcb and his powersupply design, except I'll use 4x39000 instead of 8x22000 caps. This gives a bit less F but I dont think this will hurt the quality of the psu? Btw, is 4x22000 per rail better than 2x44000?

If anyone has any objections regarding the parts I've chosen, please advice.

My next worry is the physical layout of the amplifier. I've attached a picture of two possible solutions(forgive me the crude drawing but hopefully the idea will get across.) Wich one is better when trying to keep noise from trafo, power wires etc. away from pcb and signal wires? Will the difference be negligable?

Regards

Eystein
 

Attachments

  • amp.jpg
    amp.jpg
    12.5 KB · Views: 502
Sorry, I was a bit unclear on that one. What i meant was CCLCC instead of CLC. Is there any difference.
And thanks for the reply. I too think the top one is the best, but size is also an concern. The last one will be a bit smaller(no big isn't always beautiful :))
Will there be much difference though? I guess this i difficult to quantify just from a drawing but if I risk noise with the last I'll obviously go for the first.
 
Moderator
Joined 2003
Paid Member
From memory (can be wrong at my age :D ) I think Nelson does something like CLCLCLC or from picture of XA200 it was CRCRCRC.
PCB further from PSU is always better unless you use a good shield (Hum).
Good ground connections (star ground) is also very important. Try to pay much attention to that.

/Hugo
 
Depending on the height of your Conrad heatsinks (I'm getting the 151mm high, double-flanged kind, personally) and the height of your transformer and capacitor, you could end up with the tops of the capacitors sticking out of the top of your amp if you put the caps over the transformer.

That said, I'd go with your upper drawing provided that it all fits under the lid. (I wish it did with mine. :()

Erik
 
We're getting the same heatsinks then. If I go with the first picture, my plan is to add a cm of height using the bottom plate of the amp. My plan is anyways to bend it at the sides to mount the heatsinks. Adding height is just a matter of mounting them higher on the bent bit. (if you understand my explanation. :)) If more space is needed, a possibility is to put the caps on their side. This will save space for their mountings top and bottom.

Dimensions then will be 30x26x16 for one monoblock. The front plate will hide the little cm anyways.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.