Valve orientation ?

[Audio Al]

Come on you people who know , a question for you

Why were all older valve amps built with vertical valve positioning , and in current models they are positioned horizontally , as in Croft valve amps and other makes :scratch:

I can see that heat disipation on vertical valves would be even heat loss ,
However on modern amps surely they would run with a cool side and a artificialy hot side ?

Would this be detrimental / have a affect on the valves ??

:)

[montesquieu]

plenty old amps had horizontal valves?

[Primalsea]

I think older power amps were built to be put in boxes, so having the valves vertical just made it easier for replacement. Mostly pre amps and radios that were to be on display just had the valves inside anywhere they would fit with enough clearance to dissipate enough heat. The format just kind of stuck.

This is just a guess.

[User211]

Generally those running horizontal valves were/are held inside cases, no?

It is just safer and probably cheaper as no valve cage is required.

I honestly don't think you've spotted a trend, though. As Tom implied.

[walpurgis]

I have left and right monoblock power amps. The valves in my left monoblock are horizontal and in the right monoblock they are vertical. Can you figure that out? :)

[Audio Al]

I have left and right monoblock power amps. The valves in my left monoblock are horizontal and in the right monoblock they are vertical. Can you figure that out? :)

:eek: Err Nope :)

[Stryder5]

Is it a case (sorry) that generally the trend is for lower height enclosures, so the valves are mounted horizontally?

Smaller enclosures less cost for manufacture?

[walpurgis]

:eek: Err Nope :)

They are a mirror image pair that can be stood or laid down. Like this.

http://i68.tinypic.com/344a4br.jpg

[Audio Al]

They are a mirror image pair that can be stood or laid down. Like this.

http://i68.tinypic.com/344a4br.jpg

My head hurts , now I have 45 degrees to contend with as well :confused::hmm:

[Jazid]

Valves sometimes require an orientation, with the filaments running vertically, especially directly heated power valves.

The reason is that as the filaments heat up they expand and sag. If oriented horizontally the filament can sag and touch the grid or even the anode. This can make things go pop.

All valves have a recommended orientation in their datasheets, for most indirectly heated and small signal valves it is specified as unimportant. Upside down is a poor choice for obvious reasons but acceptable for testing purposes.

Some directly heated valves may also be used horizontally as long as they are rotated so that the filaments cannot sag onto the other elements.

Sent from my GT-I9195 using Tapatalk

[anthonyTD]

Mostly valves are positioned other than the normal ie; vertical, due mainly for convenience of the design, valves have a better life generaly in the upright, or vertical position, as the heat is designed to go up the valve evenly, the worst position is upside down, as in many Guitar amps, but as I said, its mainly for convenience of the design.
Hope this helps. :)
A...

[Firebottle]

Some of the all valve oscilloscopes of yesteryear were so full of valves that a lot had to be mounted 'upside down'. They all had lots of perforations in the casework.

[walpurgis]

I wonder an any non-valve electronic devices have orientation demands (and I don't want any bright spark suggesting mercury switches :)).

[struth]

mercury switches:ner:

[Barry]

I wonder an any non-valve electronic devices have orientation demands (and I don't want any bright spark suggesting mercury switches :)).

Yes - on shipboard military electronics, the heavy transformers are mounted at the base. There is an apocryphal tale of a piece of military navel electronics where, for reasons best known to the designer, the transformers were mounted at the top of the rack - that is until they fired off a big gun and all the transformers ended up at the bottom!

[alphaGT]

I have left and right monoblock power amps. The valves in my left monoblock are horizontal and in the right monoblock they are vertical. Can you figure that out? :)

So they won’t cross-conbobulate. If they were all pointing in the same direction you might tear a hole in the space-time continuum! And who wants that?

Russell

[anthonyTD]

Aye,:) used to use an old telequipment scope when I started, [see link below for some of the classic versions ] I still have mine, and remember re-building the amplifier boards in it, its crap compared to today's standards, but it worked for me at the time, and I can't bear to part with it!
http://www.thevalvepage.com/servdata/testeq/telequip.htm
Some of the all valve oscilloscopes of yesteryear were so full of valves that a lot had to be mounted 'upside down'. They all had lots of perforations in the casework.

[Firebottle]

I had a mate that started collecting valve radios, he did amass a seriously good collection. He couldn't say no to anything with valves in so ended up with valve scopes in his hallway and most of the way up the stairs.
http://www.thevalvepage.com/index.shtml