Aleph5 heatsink help!

This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I need a piece of advice concearning aleph 5 heatsinks.

I'll use the following on the picture: 6xPR223(200mm height) from Alutronic (for both channels) and a total weigth of 22kg.

Am I going over or under the top??

The PSU is NP original Design and everytinhg is the same as the original.


  • aleph 5.jpg
    aleph 5.jpg
    71 KB · Views: 964
Em Portugal??

Eu compro em (dissipadores) e (componentes)

translation: (to the other non PT)

I buy in (heatsinks) and (components).

Advice to sapito:

If U want to talk in a language other that english email directly, because this way just a few people get the message :D

my email is on "profile" go see it!

Were do you live anyway?
Hello Pedro,

for a Aleph 5 you need to dissipate about 250-300 watts for two channels. If you want your heatsink to be 55° at 25°C ambient you will need 30/300=0,1°K/watt heatsinking for the amp.
So your heatsinks (when using 6) must have a rating lower than 0,6°K/w wich seems to be the case.

I don´t think you can overdo the heat sinking, it´ll give you some room to play with the bias and cooler will live longer.


P.S. You could have found this answer when using the search function:D
I realy dont understand a think about heatsinks specs.

The only spec I can understand is this ratio:

Euro 17.50/kg :D

So I asked to see if anyone has done a similar aleph % with the same amount of heatsink. All the aleph 5 sinks I have seen seem a little small.

And yes, I performed a search otherwise I couldnt have started a new thread :)

thanks for the help anyway
I once tested a heatsink like those you've mentioned. Except it's height was only 150mm. It reached a temperature of about 50 deg C dissipating 50W at room temperature. Having six of them and 200mm height it should be more than adequate for dissipating 300W.
Good idea??

I am almost finished with my Aleph30 and just got hold of 2 of the following heatsinks which I would like to use for an Aleph5, but as 2 monoblocks, or actually mono towers - if I can call it that. The lenght of each are 450mm, is it wise to use it as a tower, or will it be too small? I realise that the heatdisapating ability will change when 1 turn this heatsink on it's head, but am not sure what the effect will be, better or worse???? :xeye:

Heatsink info are from Fischer:


  • sk108.jpg
    21.4 KB · Views: 616

Notice that by looking at the curve, it's getting pretty flat at 200mm length, indicating tha increasing length past that point doesn't get you much. It appears that it should be about .45K/W at 200 mm long. If you cut what you have in half, and use two per monoblock, you would effectively get ~.22K/W. That's before taking into account anything else though. Like... maybe that graph is for an operating temperature of 100C on the sink, and you don't want to operate there. You should check.
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.