Brushless fan install on a Hot Rod Deville

[TubeeTuberton]

This should be relatively easy but, I am wanting to install a Brushless DC Fan on Hot Rod Deville 212 to keep it a bit more cool in back. Where I play the amp has to be sort of against a wall not allowing for much breathing room. Anyways, I figured I should be able to install a DC fan pretty easy. I haven't found much online that is real helpful. I have access to numerous fans and even computer power supplies, stuff like that. I was thinking I could just tie into the RED LIGHT on top of the amp and it's leads. Or maybe use a PC power supply tied into the main power switch. Something.

Please let me know if you have any ideas on how to accomplish this. Any input is welcome. Thanks in advance.

[TubeeTuberton]

any technical folk here? not trying to bump a lot but, kind of bored, sorry.

[SatelliteAmps]

There are ways to do it, but rarely do fans actually help anything in an amplifier. You can run it off the filament supply (the red light).

Most amp's are designed knowing that they won't get a lot ventilation, making a fan unnecessary. Using a fan to try and blow cooler air on hot tubes doesn't do anything positive for the amp. The negatives are mostly about cold air on hot tubes (which is can cause thermal issues with the glass, cracking and whatnot), noise, and also a drain on the filament supply if the fan needs more than the amp can put out.

[Geetarpicker]

I have used both AC whisper fans and more modern small DC fans it's own power supply. Some amps really don't need any cooling assistance, but I really think it helps things to last. Combo amps can run especially hot as the tube heat raises into the chassis.

Radio Shack makes a bunch of transformer type adapters but also sells a transformerless AC/DC adapter that has multi voltages. I have that in my '68 Marshall and also had one in a Vibrolux reverb. The cool thing is the unit doesn't cause any hum pickup even if the wall wart is close to the chassis as there is no transformer period to create a hum field. I have mine pull tied right to the top of the Marshall chassis near the preamp side and no problems. I think the unit has 3, 6, 9, and 12v and maybe a couple others. With a 12v DC fan that gives you some quieter lower speed options. The downside is the transformerless adapter is pretty pricey.

Yep, you might be able to tap into the amps power supply for some DC but that is uncharted territory so research that option well. You could also use an AC 120v right off the main switch. I use to runs fans in old blackface/silverface Fenders and would rewire the back outlet to be switched with the main power and plug the fan in right there so I didn't have to drill a thing.

I don't think tubes really need cooling assistance in most amps, however other components might benifit from forced air cooling. Some blackface Fenders run so hot the black paint on the transformers get sticky hot by the end of a long loud session. I think some cooling help might help to gain more years of hard service off the transformers. That said, lately I've been runing my '64 Fender Deluxes without fans and the PT sure are hot by the end of a cranking gig. Still the amps are over 40 years old, and somehow the original transformers sure take a licking and keep on ticking.

[donnyjaguar]

Tubes cool via radiation. That said, like all electronics, the cooler it runs the longer it lasts. A 12Vdc muffin fan is cheap insurance IMO. Most of these are 12Vdc so like I mentioned before, put a voltage doubler on your 6.3Vac filament supply and run it from that. All you need are 2 1N4007 and 2x 1000uF and you're in business. The red light is typically the 6.3Vac supply.

[TubeeTuberton]

Tubes cool via radiation. That said, like all electronics, the cooler it runs the longer it lasts. A 12Vdc muffin fan is cheap insurance IMO. Most of these are 12Vdc so like I mentioned before, put a voltage doubler on your 6.3Vac filament supply and run it from that. All you need are 2 1N4007 and 2x 1000uF and you're in business. The red light is typically the 6.3Vac supply.

That is exactly what I am talking about. Where can I get these items and maybe, possibly, a wiring diagram...? :)

[donnyjaguar]

The circuit is so simple I'll endeavour to explain here.

You'll have two leads from the 6.3Vac supply. Let's call them top and bottom. First off, take your two 1000uF cap's and wire them in series, with the negative terminal of the top one attached to the positive of the bottom. The bottom lead of the 6.3Vac supply attaches to the point where the capacitors are joined. Place a 1N4007 diode with the anode end attached to the top of the 6.3Vac supply and the cathode (the one with the bar) attached to the + terminal of the top 1000uF capacitor. Now attach another diode's cathode from the top of the 6.3Vac with its anode attached to the bottom neg terminal of the bottom 1000uF capacitor. Your 12Vdc will appear across both capacitors with + being the + of the top cap.

Draw it out and it'll make perfect sense.

Any electronics store should have 1N4004/1N4007 diodes and 1000uF/25Vdc capacitors. These aren't expensive components. You can up the capacitor value if you like, but I don't think a muffin fan cares too much about any hum.

[TubeeTuberton]

Yep. Got them last night. I will wire it up tonight. Thanks again.