Valve amp cooling

timmysoft · May 2016

I recently acquired a really cool Landry irt studio rack amp, I love how compact and flexible it is, so I'm looking at putting it into a super compact rig for rehearsing and taking to recording sessions. With that in mind, I obviously want to keep the rack case small, but the unit itself develops a fair amount of heat. So does anyone know of a heat dispersing tape or maybe using something like computer heat sinks would help?

ecc83 · May 2016

First of all if the rack will have multiple units in it the amp must be at the top so it doesn't cook stuff above it.

I notice it has an internal load? If you could remove this and put it in a well heatsunk tin behind the rack somewhere that would remove some 15W from inside the case. Or perhaps you could just jack in a remote load? 15W might not sound a lot in this "Loud as F!" world but believe me, 15W in a confined space generates a lot of heat.

You will want a rack grill at the top and best one below the amp, depends how the "free air" convection is arranged. I am not a fan (Boom! Boom!) of fans in amps but sometimes there is no alternative. You can get "slot" fans for racks but they are probably quite pricey. You could probably adapt something from the computer cooling world?

Heatsinks are only of use if you can intimately attach them to the "hot bits" tricky with valves. Yes, if you could bolt 1,000sg mm of fins to the case, that would help but you want Compact & Beejew!

In fact it is not the valves that will suffer from overheating so much as electrolytic capacitors and to some extent, transformers (think on you 99% hot biasing wannabees!)

Sorry to be of little help.

Dave.

ICBM · May 2016

Many rack units are poorly designed for cooling, apparently on the assumption that they will not be put in a rack! Or how else do you explain vents in the top, or even the sides…

The only really sensible arrangement is fan cooling with through flow from back to front, or at worst in and out of the back - although that can lead to the same air being recirculated and getting hotter and hotter.

If it doesn't have that sort of arrangement and you can't arrange a cooling space above, you'll probably have to fan-cool it from the outside as Dave says. You should be able to mount a small fan on the case somewhere so it at least circulates air around the outside of the amp.

Sassafras · May 2016

timmysoft said:

I recently acquired a really cool Landry irt studio rack amp, I love how compact and flexible it is, so I'm looking at putting it into a super compact rig for rehearsing and taking to recording sessions. With that in mind, I obviously want to keep the rack case small, but the unit itself develops a fair amount of heat. So does anyone know of a heat dispersing tape or maybe using something like computer heat sinks would help?

You've answered your own question.

ecc83 · May 2016

As I suspected, "proper" rack fans are well into 3 figures. You could probably adapt a couple of these..

https://www.google.co.uk/search?q=slot+cooler&biw=1093&bih=525&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjDzsqOlPDMAhULBsAKHYVfC-QQsAQIYg&dpr=1.25#imgrc=JAZmay6ONQ5Y7M%3A

to your purpose. Note, you want the fan to PULL hot air out of the rack and cool air must get in easily, preff' through a filter.

Dave.

olafgarten · May 2016

I think your best best is PC Fans. You can get a 120mm fan for about £5 each, a 10 fan distribution box for £10 and power it from a 12v DC supply that you fit a Molex connector to.

From my experience cooling PC's this is a good fan:

https://www.overclockers.co.uk/bitfenix-spectre-120mm-fan-white-fg-000-bx.html

For distribution:

https://www.overclockers.co.uk/nzxt-fan-grid-multi-channel-distribution-fan-black-ca-140-nx.html

The PSU could be something like this:

http://uk.rs-online.com/web/p/plug-in-power-supply/7300237/

With the full 10 fans it would be around 600mA but it's nice to have some headroom.