Dx blame

[amplidude]

Hi .
I am building the dx blame, and i have a question regarding heatsink.
I'm on a budget so I'm using an old chassis, it's going to get a paint job, quite a yellow chassis, the heatsink are from an old pa amplifier and weigh around 5 kilos, my only problem is the fins, they are horizontal, convection must be degraded or am I wrong, adding some pics

 

[PRR]

I would cut it in half and stand the chunks fins-vertical.

 

[rayma]

I would cut it in half and stand the chunks fins-vertical.

Or mount a fan over the middle of the fins as-is, and blow cool air into the fins
(impingement cooling). How much heat dissipation for this circuit?

 

[amplidude]

I think I'll go for option one, cut them, I don't like having fans, I think in iddle it uses roughly 60w or more, it's a 20 output device.
Thx for clearing my doubts.

 

[6L6]

Look at the layout of the heatsink, there appears to be 4 big power transistors on each side of a small group of 3 transistors used for the temperature compensation.

I'd be weary of splitting the heatsink, you'll need to be careful of where the cut is, and also make sure one side of the sink doesn't get hotter than the other.

The case has a nice big hole for a fan, there are quiet fans that when run on lower voltage become essentially silent.

 

[rayma]

The case has a nice big hole for a fan, there are quiet fans
that when run on lower voltage become essentially silent.

Fans are your friends.

 

[amplidude]

Been offered theeese 2 heatsinks they measure 200mm by 650mm, thinking about cutting them into half and use them as topplate and mount the amp module underneath and nice wooden sides, am thinking two mono blocks, would that work, heatsink area is then 400 by 325mm, the weigh 6.5 kilos each.