Running a rack amp upside down ?

[Brett - K A L I S I A]

Well, not really upside down but vertically instead of horizontally. Does anybody know if there's something wrong with that ?

 

[Jackal_Strain]

Can't think of a reason why it should be a problem.

 

[Brett - K A L I S I A]

Me neither, but if someone one knows one, please chime in

 

[doc_backmask]

I could imagine one problem being putting a directional stress on the tube mounts (most important for the power tubes since they're bigger). I don't expect that this problem would manifest itself quickly, but over a lot of time and travel (read: bumping of rig, rapid directional force changes) this could cause some loss of connectivities inside the box. But I'm a chemist not a physicist, so others may be wiser.

 

[nwright]

Doc, remember that some tube amps have the tubes upside down and/or sideways as it is...5150's preamp tubes come to mind as they are held sideways in the amp. Mark series Boogies have upside down tubes, etc. I would think running them vertically would be OK, especially if it's a solid state PA.

 

[doc_backmask]

Ah, I see. I didn't know that the preamps in 5150's were sideways. I don't play guitar (bassist) and I wasn't around when the guitarist in my band changed his tubes last. Thanks for the enlightenment.

 

[Brett - K A L I S I A]

The tubes in my rack are already vertical, so that shouldn't change anything I guess

 

[kaomao]

Just a gravity issue, if you have the base of tubes (call it tube mounts or whatever) loose, your tubes with vibrations will fall down.
Just bend those metal mounts till they have a good grip on the tubes, then you'll be fine.
I remember my old rack poweramp having springs attached to the tube base holding the tube, no matter how you put the amp, those tubes couldn't unhook.

 

[dreamcatcher]

Could there be a venting issue?

 

[Brett - K A L I S I A]

Mmmm, good call, but I don't think that would be the case unless you lay the amp on its back.

 

[batlas]

tubes no problem....im thinking transformers....those are some heavy mother*****. Having them sideways...rattling etc...they get loose and fall down maybe. Probably ok with a pre-amp but power amp....I wouldnt

 

[metalkingdom]

5150's preamp tubes come to mind as they are held sideways in the amp.

I have an old school Tubefex with two 12ax7's mounted sideways.

I used to wonder the same thing as Brett, but after seeing G3's and 4's mounted sideways I stopped wondering.

If you like to have the amp head in the control room, you may find yourself forced to place them vertically depending on how much space is available.

 

[iekobrid]

Laying a top-design vent on its back would be worse, certainly, but even turned sideways I imagine there would hot air passing over / accumulating around internal components it would normally be drawn away from. Whether there's enough to cause a problem, who knows.

 

[Mindmare]

The electrolytic capacitors contains fluids which could flow to the lower end of the capacitor (specially if the amp is old and the capacitors are more or less dried out). This could change the tone and maybe even cause functional problems. The capacitors are almost always mounted so the fluids even out over the length of the capacitor. However I'm pretty much guessing here, would be nice to get it confirmed by an electronics expert