Why make heads with the glass upside down?

Discussion in 'Amps and Cabs' started by WBellman, Jun 12, 2019.

  1. WBellman

    WBellman Supporting Member

    Messages:
    1,016
    Joined:
    Oct 18, 2018
    Convection cooling is a wonderful thing. Why some head makers still design upside down puzzles me. I understand the economic reasons behind using the same chassis for both a head and combo, but why not take advantage of allowing things to run cooler? Transformers would dig it too. And the chassis wouldn't have to do most of the heat sinking.

    Gotta love how Friedman mounts his combo amps with the tubes are sideways. The knob text is upside down when viewing from the front, but that's a compromise I'll take to keep the tubes running cooler.

    Thoughts???
     
  2. Axis29

    Axis29 Supporting Member

    Messages:
    3,070
    Joined:
    Mar 19, 2007
    Location:
    La Quinta, CA
    Mounting them on top keeps the tubes from falling out.
     
  3. tiktok

    tiktok Supporting Member

    Messages:
    20,490
    Joined:
    Jun 9, 2009
    Location:
    Seattle
    Economic benefits from shared head/combo form factor outweighs minimal cooling benefits which can be dealt with via heat sinks, fans, just ignoring it since amps are rarely run hot these days, etc.

    Plus, Leo Did It That Way.
     
  4. WBellman

    WBellman Supporting Member

    Messages:
    1,016
    Joined:
    Oct 18, 2018
    Not minimal at all if you understand convection cooling (why Marshall heads have those vents on top). Only amp I ever owned that included a nice little quiet fan was a Fuchs. Wish more builders would use them - probably not more than $0.50 bought in bulk. Unfortunately, you really can't heat-sink a tube correctly, and transformers are designed to cool themselves via convection.

    cooler = better efficiency and lifespan: Electronics 101
     
    neville5000 and Scrapperz like this.
  5. willie k

    willie k Silver Supporting Member

    Messages:
    1,843
    Joined:
    Sep 30, 2009
    Location:
    Roswell, GA
    The tubes being upside down means the amps are made for heavier rock. You see, tone electrons are generally happy and light and have no problem with upright tubes. When you crank out the metal jams, the heavier electrons struggle against gravity. By turning the tubes upside down, gravity becomes your friend again. Simple physics, really.
     
    Last edited: Jun 12, 2019
    J Factor, Badtone, Mk90 and 11 others like this.
  6. slayerbear17

    slayerbear17 Member

    Messages:
    1,742
    Joined:
    Aug 13, 2010
    Location:
    YYC

    As a gigging musician that's the last thing on my mind. While I agree with you I doubt you would get much more mileage if you could have the perfect cooling system, even if you did how much longer can you increase lifespan? I think there's just too many factors involved.
     
    rizla likes this.
  7. slayerbear17

    slayerbear17 Member

    Messages:
    1,742
    Joined:
    Aug 13, 2010
    Location:
    YYC
    As a Thrash Metal Musician I concur!
     
  8. WBellman

    WBellman Supporting Member

    Messages:
    1,016
    Joined:
    Oct 18, 2018
    Speaking of heat-sinks. They are designed to work well if mounted upright or sideways. Extremely inefficient if mounted upside down.

    [​IMG]

    Same thing basically as far as heat goes.

    [​IMG]

    Bet you couldn't touch the chassis of SRV's twins for at least 15 minutes after a gig. :D

    [​IMG]
     
  9. gruenburger

    gruenburger Supporting Member

    Messages:
    259
    Joined:
    Jun 27, 2009
    Location:
    Miami
    electron integrity is preserved in an upside down crystal lattice configuration. the neutrons on the other hand...
     
  10. slayerbear17

    slayerbear17 Member

    Messages:
    1,742
    Joined:
    Aug 13, 2010
    Location:
    YYC
    I cant think of any good reason to touch a chassis straight after a gig.
     
    Washburnmemphis likes this.
  11. WBellman

    WBellman Supporting Member

    Messages:
    1,016
    Joined:
    Oct 18, 2018
    I bet changing tubes mid-show was rough though :p And the man was known to blow through his fair share of them!
     
    slayerbear17 likes this.
  12. PurpleJesus

    PurpleJesus Staff Member Supporting Member

    Messages:
    8,196
    Joined:
    Jul 11, 2014
    The dude played 13's, his hands had to be devoid of pain receptors. ;)
     
  13. tiktok

    tiktok Supporting Member

    Messages:
    20,490
    Joined:
    Jun 9, 2009
    Location:
    Seattle
    That would explain why all those Fender designs are so prone to thermal failure on the gig.

    I know the theory, and I'm sure that if amp manufacturers were going for mil-spec reliability, the design would be different, but for real world use scenarios and economics, apparently it doesn't matter that much.

    Consider that having flat amp tops encourages people to set drinks on top, which can then spill into the amp causing all manner of mayhem. Why not make the top of the amp head in such a way that no one sets a drink on it? Because the cost/benefit ratio is out of whack.
     
  14. gldtp99

    gldtp99 Member

    Messages:
    3,041
    Joined:
    Dec 23, 2005
    Location:
    Texas
    Are you sure you're not overthinking this ?

    I have many Fender amps from '62, '64, '65, '66, etc. that have been working fine all their lives with the tubes/transformers mounted under the chassis.

    I also have two 100 watt Marshalls (a '73, and a '78) that have convection cooling (tubes/transformers on top of chassis and vents in the top of the cabs to allow heat to escape) and have suffered PT failures in their lifetimes.

    Sometimes components just fail----- it happens.

    It doesn't mean the engineers at Marshall or Fender were ignorant fools.

    I believe they did a good job with the classic amps of the past.

    But maybe now, in 2019, the OP can come up with better designs.

    And he will instantly become rich and famous--- :cool::cool::cool:
     
    HotBluePlates likes this.
  15. WBellman

    WBellman Supporting Member

    Messages:
    1,016
    Joined:
    Oct 18, 2018
    orange juice + Marshall 50W head = lots of costly mayhem. But for a second there, the colors coming out of it were cool!

    Of course. Just bored and up for some discussion. Seriously though, since working in electronics it's always been a thing with me - same goes with batteries in stomp boxes. Never use them and always make to to have lots of ventilation - small quiet fan - with combos. It's not needed, but neither is Eric's rubber band ;)

    [​IMG]
     
  16. Kyle B

    Kyle B Supporting Member

    Messages:
    4,684
    Joined:
    Sep 10, 2012
    Location:
    Western NY
    Tubes like being hot

    Capacitors & resistors on the other hand...

    It's a well known 'rule of thumb' (almost a 'fact') that for every 10 degrees cooler you run your capacitors, they last 10x longer.
     
  17. FbIsNotE

    FbIsNotE Member

    Messages:
    3,120
    Joined:
    Apr 28, 2017
    Location:
    The Bay State
    I don't know why some manufactures do that. Mesa doesn't and it's something else to like about them for me. I'm no expert, but it seems to be the same chassis and they put in the extra effort / cost to do a second silk screening to keep the text correct on the other version.

    Triple Crown head

    [​IMG]
    [​IMG]

    Triple Crown combo
    [​IMG]

    [​IMG]
     
  18. BluntForceTrauma

    BluntForceTrauma Member

    Messages:
    2,909
    Joined:
    Jun 6, 2014
    Location:
    Tucson, AZ
    I've used a $2 12V DC computer fan run off a 9V DC wall wart attached to the back of several amps. Cost almost nothing.
     
    Baxtercat likes this.
  19. Husky

    Husky Gold Supporting Member

    Messages:
    9,730
    Joined:
    Nov 5, 2008
    Two schools of thought.
    Hanging down Fender style drives heat in to the chassis but keeps floating debris off the tube internal elements instead of shorting things out like a reservoir tip;-). Tubes up is less hot but bits flaking off can short the tube out. In general I’ve never experienced a reliability issue with old Fender amps. My Super Reverb gets hot for sure but never breaks down.

     
    Last edited: Jun 12, 2019
    BobK, NorCal_Val, JPH118 and 3 others like this.
  20. SweetSAAB

    SweetSAAB Supporting Member

    Messages:
    190
    Joined:
    Oct 23, 2008
    Location:
    Tulsa, OK
    Are you sure your knee level computer speakers even have tubes? You might want to double check.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice