Tube Amp On It's Side OK??

Jon James · Post by **Jon James** » 24 Jul 2005 1:41 pm

Can anyone tell me if there is any damage that can be caused to a tube amplifier if I leave it permantly on it's side. I have just totally run out of room for my stuff, and the one little 6' of wall space that my wife has a lotted me in our family room for my music stuff is just too tight, so I figure I can save a lot of room by putting my 2x12 tube amp on it's side, and that way I can point it at me while I practice also. Any problems?
Thanks

Donny Hinson · Post by **Donny Hinson** » 24 Jul 2005 2:20 pm

Just make sure the power tubes are on the bottom side. That way, the heat they give off will have to travel farther to get to the wood cabinet.

Jon James · Post by **Jon James** » 24 Jul 2005 2:28 pm

Thanks Donny,
The tubes are in the middle of the amp , so I they are equidistant from either side. Any other issues? How about the reverb unit? Thanks

Dave Zirbel · Post by **Dave Zirbel** » 24 Jul 2005 6:12 pm

A lot of times when I play with tube amps I set them on their side to disperse the heat generated by the tubes. The design flaw of Fender amps is that the tubes are under the chassis. That's why the components get cooked and dry up and need to be replaced more often.

David Doggett · Post by **David Doggett** » 24 Jul 2005 8:17 pm

I play through a Dual Showman Reverb head or a Super Twin Reverb head. To save space on small stages I routinely set them sideways on end. It seems to have no effect on the tube sound, and probably vents the tube heat better. As far as what Bob L. just said, in my experience there is no solid state amp equivalent to tube tone.

Ricky Littleton · Post by **Ricky Littleton** » 25 Jul 2005 4:37 am

Just my $0.02 worth based on almost 30 years in electronic maintenance.

Tubes, stored or otherwise are best maintained in an vertical orientation. The reasons are plain and simple:

1.- elements (most notably the filament)are suspended within the tube envelope at one end. Therefore, tubes left on their side for extended periods may experience (due to variations in quality of manufacture)some "sag" internally and run the risk of premature failure due to this. Even if the elements do not sag enough to directly short, the distance between the elements (a critical parameter known as interelectrode capacitance) could change and may alter the overall performance of the tube.

2.- Filaments run red-hot when running. The plate (anode) may also run a little red if the gain is way up. This means HIGH surface temperatures. Remember, metallic pliability is obtained through heating. This being the case, it is easy to see if a tube is operated on its side, the risk of filament deformation through thermally induced sag is greater than if the tube is operated upright.

In military applications, ruggedized tubes (in metallic envelopes) were manufactured with more robust elements to offset the above problems, however, our modern audio tubes are manufactured nowhere near these ruggedized standards.

Just my thoughts on this, but as I said, it's info derived from a long-time career in electronics (radar and my own repair business).

Thanks for letting me rant...

Ricky...

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Emmons LeGrande - 8x4
Session 400 Ltd, Nashville 112,Hilton Volume pedal, Peterson VS-II Tuner
Dan-Echo, E-Bow, Ibanez Distortion, Bo-Bro, Ibanez Auto-Wah, PX4 Pandoras Box

<font size="1" color="#8e236b"><p align="center">[This message was edited by Ricky Littleton on 25 July 2005 at 05:38 AM.]</p></FONT>

Jody Carver · Post by **Jody Carver** » 25 Jul 2005 5:28 am

Keep ranting I'm learning something here.

ed packard · Post by **ed packard** » 25 Jul 2005 6:23 am

Keep the heat away from those electrolytic capacitors (big silver cylinder shaped things) as they are a major source of amp problems = hum etc. as they "deform", dry up, or otherwise deteriorate.

Filament sag can also cause hum problems. As has been pointed out, the tube design is optimized for upright operation.

Dave Zirbel · Post by **Dave Zirbel** » 25 Jul 2005 6:47 am

That makes sense to me about tubes being vertical. I guess I'll just run a small fan in the back of my amp, or set my amp upside down.

I learned something too!

DZ

Blake Hawkins · Post by **Blake Hawkins** » 25 Jul 2005 7:46 am

In modern equipment, the only tubes with filaments are rectifiers like the 5Y3GT.

In the "RCA Tube Manual Technical Series RC 23" It is stated that vertical mounting is preferred but horizontal mounting is permissable if pins 2 and 8 are in a vertical plane for a 5Y3GT.

Of course, you don't usually find tube rectifiers any more. The Fender Twin's use solid state diodes.

The construction of all the other tubes in the amp is "heater-cathode" where the heating element is tightly packed into a sleeve which is the cathode.

The tube manual states for the 6L6-GC and for the 12AX7A that "the tube may be mounted in any position."

This is not to say that you wouldn't encounter any of the problems mentioned above including internal distortion of other tube elements.

However, the manufacturer was confident enough to reccomend mounting in any position for the heater-cathode tubes.

Blake