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Upside Down Tube Amp
Upside Down Tube Amp
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Old 7th October 2011, 03:24 AM   #1
EdwardATeller is offline EdwardATeller  United States
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Default Upside Down Tube Amp

Just bought an all-tube guitar amp, and after running it for a while, the front panel was getting REALLY hot. Stop the presses, right? Anyway, there is a big opening in the back with all the electronics up at the top of the space. I decided to turn the amp upside down, and see if it stayed cooler. Mission accomplished, but after jinxing myself with that famous phrase, I started wondering if I was doing some damage. Based on my cursory inspection, the tubes are stuck into the bottom of the other electronics in the normal amp orientation. I guess this means the tube are upside down, and by turning the amp over, they are now right-side up. Based on what I've read, this seems to be the happiest way for tubes to exist, plus the other components aren't getting cooked. Have I answered my own question? Maybe, but I'd be doubly blessed if some of the tube gods would deign to offer their approval, or equally useful, point out where I've gone wrong in running my amp upside down.
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Old 7th October 2011, 03:45 AM   #2
Bigun is offline Bigun  Canada
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Upside Down Tube Amp
As far as I know, all tubes can be run upside down (so long as they don't fall out of their sockets !!). The issue is more that some tubes can only be operated on their sides if they are rotated to a certain orientation so that there isn't any chance of hot wires inside the tube from sagging under gravity in the wrong direction.

Seems to me you've solved your problem.
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Old 7th October 2011, 04:21 AM   #3
cerrem is offline cerrem  United States
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Some Audiophiles might say that gravity will affect electrons in transit, depending on position of tube
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Old 7th October 2011, 04:50 AM   #4
6L6 is offline 6L6  United States
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Upside Down Tube Amp
Get a small, cheap fan from the store. Blow it onto the amp. Problem solved!
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Old 7th October 2011, 04:59 AM   #5
rknize is offline rknize  United States
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It's a pretty common configuration for guitar amps. Aside from the practical purposes of chassis size, it also puts the tubes right next to the speaker. I suppose that tube microphonics play a part in an amp's "tone" (or whatever you call it).
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Old 7th October 2011, 08:25 AM   #6
Gilgy is offline Gilgy  United Kingdom
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Some tube data sheets include specifications about things like correct orientation, minimum spacing and the approved rotation of tube sockets. Many (most?) guitar amp manufacturers seem to have nothing but contempt for such tedious minutiae and cobble their amps together just as they see fit, possibly viewing cooked capacitors as a rite of passage for their products.

Fender, Marshall and countless other combo amps are made with inverted tubes and they work more or less reliably. Maybe they're less reliable than the corresponding head amps which have the tubes the other way up? And maybe someone will argue that the heat cooks extra tone into the tubes and makes you play like Jimi Hebdrix.

I wouldn't worry about it. And your amp will look silly upside down.
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Old 7th October 2011, 09:27 AM   #7
trobbins is offline trobbins  Australia
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Send the amp to me - I'm sure it will sound better and run cooler in the southern hemisphere ;-)
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Old 7th October 2011, 11:09 AM   #8
Doz is offline Doz  United Kingdom
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Wasn't there a Danelectro amp that had a diagonal chassis??
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Old 7th October 2011, 01:16 PM   #9
indianajo is offline indianajo  United States
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My 59 ford car radio had all the tube pointing down. Worked fine, except one time I was crossing the warning strips before a toll booth and a tube fell out. WAKY was playing "Good Vibrations" at the time, too, a real disappointment.
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Old 7th October 2011, 02:30 PM   #10
digits is offline digits
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Originally Posted by cerrem View Post
Some Audiophiles might say that gravity will affect electrons in transit, depending on position of tube
other audiophiles will claim to be able to hear it.
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