Cooling of Tube Amps

[bpalmer]

Sorry folks haven't been here in awhile....this new Message Board format is kinda' "freakin' me out" until I get used to it. Hope I do this right.

I've got a Marshall DSL 40 1X12" Combo Amp (that I love) and it gets (as most Marshall's probably do) hot to the touch on the knob panel after about 30 minutes or so.

I've heard many pro's and con's to wiring in a cooling fan to the amp (some don't like the humming of an internal fan and afraid it will affect their sound)...but would putting a regular stand alone fan aimed at the back, work as well??? You gotta' watch slippery fingers falling on that Gold Plating when trying to tweak knobs after awhile!!! OUCH!!!

We've all seen companies like Crate with the Blue Voodoo amps (or make that Red for the Sammy Hagar fans like me!! HaHa) and Peavey with the new JSX Satriani head put up the grates with open passage ways to allow the tubes to get air from the back and the front....does that really help any??? Maybe need to modify my 5150 head for that also.

Any suggestions???

[Guest teefus2]

what tubes does the dsl40 use? el84's get real hot real fast. i used to put cooling fans in the pv c30's i used since it used el84's. as long as there is a path for air to get across the power tubes and no solder joints are melting you are probably o.k.

quimby used to use a clip on a/c fan to cool his amp heads when he got backed into a corner, that may help too.

[Scottcrud]

I've had a cooling fan in my .50 cal+ Boogie since it was new and many Boogies come stock with a cooling fan. I'd do it if I were you.

[Jeff R]

I'll echoplex you on how hot the DSL40s get. I have one (recently acquired to replace my Marshall halfstack, and I LOVE this amp too) but you can light a smoke off the chassis the sucker burns so hot.

Me and Cajun Boy have been talking about installing a fan in its box to circulate some air a little, but our "shit to do list" stays pretty full so nothing's on the slate. We probably need to push that project up in priority because while the amp's tones are killer, the build quality inside is, eh, questionable, especially when the thing could very well boil its own solder joints if you run it for too long.

Yep, EL84 power section, just like the Crate Vintage 30 1x12 I had that ALSO ran so hot you could cook your breakfast while you practiced!

[bobbymack]

I run El84 amps most of the time, and I hang an adjustable 4" fan I got at WalMart off the back panel of the head, aimed inward. Takes an extra power plug, but it keeps air moving through the back of the head...

[tgoss]

For a permanent installation, get a 220/240 volt equipment type cooling fan.

It'll run at half speed. Still enough to cool things off and less chance of 60 cycle hum.

[bobsessed]

Why do you suppose the amp manufacturer didn't install fans? My amps get mighty hot too. A certain amount of heat is needed by the tubes for them atomic particles to move around...how much is just enough? -Bob-

[tafkathundernotes]

Why do you suppose the amp manufacturer didn't install fans? My amps get mighty hot too. A certain amount of heat is needed by the tubes for them atomic particles to move around...how much is just enough? -Bob-

Everybody has to meet a price point. If convection cooling will do the trick, they don't bother with the fan. Such compromises are made throughout all consumer electronic gear. Every component is analyzed for function vs. price and price usually wins. The boutique crowd doesn't have to worry about it quite as much because money is less of an obstacle.

Tubes are usually fine with convection cooling - fans are more important when the tube has been stuffed into a box where the heat radiated is allowed to build up.