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Open space in rack for power amp to cool?

Discussion in 'Amps and Cabs [BG]' started by Juniorkimbrough, Jul 27, 2005.


  1. Juniorkimbrough

    Juniorkimbrough

    Mar 22, 2005
    Mississippi / Memphis, TN
    Endorsing Artist: Lakland Basses
    Do you leave an open space in your rack for your power amp to keep cool?
     
  2. I wonder what the general consensus for this question is as well. I have a 4 space rack for my GK head (it came it the head) and I'm wondering that if I down size, should it be 2 space or 3 space? The vents are located in the top and front.

    What would you do?
     
  3. seansbrew

    seansbrew Supporting Member

    Oct 23, 2000
    Mesa AZ.
    I use to have a heat problem with one of my amps. I did not have any room left in my rack to give the amp breathing room. I went to an electronics store and purchased a cooling fan; the kind that you put in a computer. I soldered a plug to the contacts and mounted it just behind that amp (its about 1" wide and 3.5" square). Another thing I did was drill 1/2 inch holes in my rack case on the side that the amp vented. I installed ferrules in the holes so it would look neat. My heat problems went away. If I have any space in my rack I will put it around my amps so they do not overheat, or I will install a fan.
     
  4. Juniorkimbrough

    Juniorkimbrough

    Mar 22, 2005
    Mississippi / Memphis, TN
    Endorsing Artist: Lakland Basses
    i've heard people recommend this but i've seen a lot of racks FULL of gear...

    personally my power amp has a fan in the back that pushes the air forwards out the front of the amp.....think i would have any problems cooling wise?
     
  5. Sutton

    Sutton

    Mar 3, 2005
    Plainwell, MI
  6. TheEmptyCell

    TheEmptyCell Bearded Dingwall Enthusiast

    Jul 16, 2005
    Syracuse, NY
    I've got an 8 space right now, with a 2-space and 1-space vent panels and a 1-space shelf. I leave one space above the SVT3-Pro, cuz I was paranoid at first, then the shelf and 2 space vent, and then my PC and tuner. I'm gonna take the vents and shelf out and put a small house fan in there for my own coolings purposes.
     
  7. I always do. If it ventilates front to back, with no vents on top or sides, it may not matter but it will never hurt.

    Randy
     
  8. C-5KO

    C-5KO

    Mar 9, 2005
    Toronto, Canada
    That's real cool. I made a makeshift one just like that with some old computer fans and a little toggle switch. I'd be interested in seeing what sort of adaptor it uses for power.

    If they're available in Canada, I'd probably get one. I'm not that confident with my electrical connections in my MacGyver job.
     
  9. konfishily

    konfishily

    Jan 24, 2004
    Brooklyn, NY
    It depends on how much power the poweramp produces too. But yea i would definately keep one space clear for circulation of air.
     
  10. seansbrew

    seansbrew Supporting Member

    Oct 23, 2000
    Mesa AZ.
    I forgot to mention, I live in Arizona where it can get very hot in our practice space and at the gig. During the summer If you are playing an out-door gig in the middle of July (lets say around (9:00 pm) it is still well over 100 degrees. Making it hard for the amp to keep cool.The thermal switch on my amp kept cutting the amp off due to heat. Once I installed the fan, the problem went away. I would say don't worry about your amps if you are not having any problems. But if you can help it, give your amp a little breathing room.
     
  11. adouglas

    adouglas

    Jun 23, 2003
    Bridgeport, CT
    If it's got a fan and vents in the front and back, I wouldn't worry too much...air is being forced through the amp. Space above couldn't hurt, though.

    My amp is a Stewart World 1.2, which has no fan, just a pair of HUGE heat sinks on the sides. The docs do say to leave space above and below it. It occupies one rack space.

    I've got it one space up from the bottom in a 4-space rack. The top space holds my preamp (also a 1U chassis). I didn't put any front plates in the rack, so it's completely open front and back, with space both above and below the fins. Filler plates have no use that I can see...they just add weight and block air flow. Perforated plates allow air flow, but also add weight. What for?

    Anyway, no problems here.
     
  12. lowphatbass

    lowphatbass ****

    Feb 25, 2005
    west coast
    Some pieces recommend leaving a space above and/or below, others are designed around zero vertical space and only cool from front to back. It all depends on the gear.
     
  13. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    The bottom line is that the hot air has to have somewhere to go. If your amp vents to the front of back, you won't need a space in your rack.

    If your amp vents to the top or bottom, then leave a space for it. This applies to home Hi-Fi as well. I'm amazed at how many people fling CD's and other crap allover their Hi-Fi amp, blocking the vents on the top. Or worse still, put another appliance on top if it. They'd better hope they don't even run the amp hard coz the heat has no way of escaping.
     
  14. adouglas

    adouglas

    Jun 23, 2003
    Bridgeport, CT
    I agree about not needing space above gear that doesn't have vents in the top...however, such equipment often gets pretty darned hot on those surfaces anyway. Though it's a very safe bet that the designer took this into account, it can't hurt to leave space if you've got the ability to. Think of it as a safety margin.

    The cooling built into equipment isn't always adequate in the long term. I've been using Macintoshes since 1985, and was responsible for keeping all of them running in an all-Mac office at one point. There was a particular capacitor in the Mac Plus power supply (convection cooled...no fan) that would routinely fail due to the effects of long-term exposure to heat. There were a number of aftermarket fans sold to alleviate this problem. I had one computer that was left on all the time, used to host a bulletin board system...one day it literally went up in smoke when that capacitor let go.

    Moral of the story: if you can provide more of a margin, why not do it...
     
  15. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    If the amp is fan cooled and has completely internal heat sinks, it probably doesn't need any space above or below.

    But if it uses external surfaces for radiating heat, then you should leave space around those areas.
     
  16. GSPLBASSDC

    GSPLBASSDC

    Jan 25, 2005
    Phoenix, AZ
    This is a nice little mod.....just make sure that when you install the fans that they exhaust air out of the rack instead of blowing air into the rack. Having them backwards could possibly introduce small, airborne particles into your gear...and that's not good for the long term. Also, get the quietest fans you can..you'd be surprised @ how much noise these things can make which in turn gets picked up if you're recording.
     
  17. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    If the fan is at the amp's air intake, then you'd want it blowing air in. If it's at the amp's air exhaust, then you want the fan blowing air out.

    True, but in a recording studio there's also no need to have the mic near your amp rack, only near the cabinet. :)
     
  18. Lonnybass

    Lonnybass Supporting Member

    Jul 19, 2000
    Minneapolis by way of Chicago
    Endorsing Artist: Pedulla Basses
    On a related note, how soon is too soon to close up the rack cases after a 3+ hour gig? I know power amps can run pretty hot, and was just wondering if there have been any issues with the hot air not being able to dissipate.

    Lonnybass
     
  19. GSPLBASSDC

    GSPLBASSDC

    Jan 25, 2005
    Phoenix, AZ
    Two good points, Bob. Thanks for the additional info.
     
  20. haujobb

    haujobb

    Dec 16, 2004
    Wallaceburg
    After a gig, I usually turn the gain on my preamp down completely and let the whole thing sit with the power amp running at idle while everything else gets packed up. It usually takes about 5 minutes so I think that that is enough time for the exhaust fan to blow all the hot air out the back...