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Quick vintage SVT fan question.

Discussion in 'Amps and Cabs [BG]' started by THB_bassman, Feb 5, 2006.

  1. THB_bassman


    Oct 11, 2005
    Does the fan on your vintage SVT blow into, or out of the head?
    (Just recently got this one, and who knows what's been done after all these years. Right now, the fan blows air into the head.)
  2. THB_bassman


    Oct 11, 2005
    Oh come on, there's hundreds of you SVT owners in here..can't someone please just flip a switch and tell me which way the fan turns???

  3. timv

    timv Supporting Member

    Jun 7, 2000
    Chandler, AZ
    All the ones I have had blow in towards the tubes and transformers.
  4. THB_bassman


    Oct 11, 2005
    Thanks timv,
    I ask because it seems like it should be sucking the air in through the front, blowing the hot air out of the back of the cab.
    The reason it seems like that should be the case to me, is the front grill cloth would act as an air filter, and so as the air is drawn in it would be filtered somewhat, blown over the hot parts and then out the back.
    Make sense to anyone else?
  5. popinfresh


    Dec 23, 2004
    Melbourne, Aus
    Those fans would hardly be strong enough to suck air through the front cloth to be filtered...

    The just blow moving air over the tubes.
  6. THB_bassman


    Oct 11, 2005
    You make a good point, however...
    anyone have one that sucks the air out?
  7. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    No. :D
  8. THB_bassman


    Oct 11, 2005
    No it doesn't make sense? Or no, yours blows in too?
    I think it does make sense - based purely on the damage that dust can cause in these amps.
    Plus, it doesn't blow on the tubes anyway. It's mounted off to the left side, away from the power tubes and directly behind a transformer.

    But hey, I ain't the guys who designed the amp. I just wanna make sure everything's doing what they had in mind. If it is supposed to blow in, then so be it.
    Thanks for your reply.
  9. ricplyrz


    Dec 26, 2005

    Actually, that's EXACTLY how the new SVT CL works. The fan is mounted in front. (great place for it finally) It sucks air in through the grill cloth (I need to dust mine every couple of weeks) and over the chassis, through the tubes and tranies and you can feel it exiting the back.

    It makes perfect sense and is a better, IMO, setup than the older rear left fan setup. Dust on tranies and other parts causes excessive heat. The fan on my amp is very strong. Blows thru and out the rear. Also, the new design of the CL has the tubes in the middle, staggared and the air blows right through them.

  10. Ya think? :p Ever actually seen/felt the fan in an old SVT? they're pretty powerful, certainly powerful enough to suck air in through the front grille cloth. I can feel air being blown out through my grille from the rear-mounted fan, no problem.

    Mine sucks in from the rear panel (1976), though I'm sure that, in terms of cooling, either way would be ok.
  11. THB_bassman


    Oct 11, 2005
    OK- thanks all, nothing definitive is there? 30+ years of these being taken apart and re-assembled.
    Hopefully Jerold will pitch in here.
  12. Rickenbackerman


    Apr 17, 2001
    Laurel MD
    All three of mine ('73, '74, '74) blow in from the back.

    The fan does help keep the tubes cool, although I think that its main purpose is to keep the PT cool. Blowing cold air onto it is the most effective.
  13. ricplyrz


    Dec 26, 2005

    In you vintage's, the tubes are all across the rear correct? So the fan blows only on one of the power trannies primarly?
  14. Joe Beets

    Joe Beets Guest

    Nov 21, 2004
    Sucking the air in through the front, can you imagine what that grill cloth would smell like after a few months of bar gigs? The stench from the nicotine, beer, sweat, vomit and urine would be incredible. The amp head would smell as bad as my stinking carpet covered cabinets. :meh:
  15. ricplyrz


    Dec 26, 2005
    Well, now that's a different topic all together!!:p And this does hit home as I will be joining a gigging band soon to play in the Reno/Tahoe casinos.
  16. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    The fan on the back blows in.

    It makes sense, because the whole back is open. Blowing the air in circulates it more-or-less all through the entire open area.

    Blowing it out would not positively reach all the tubes. The fan might likely "short circuit " the air right around it, never pulling any from the far side. That grille is pretty open.

    Its reasonably non-critical, tubes get so hot to begin with that a little cooling of the usual "receiving-type" tube isn't a big deal. It's more to keep the case cool.... and isn't great at that...there is no guarantee that the fan won't pull in hot air that just exited the grille....

    Tubes that really need forced air cooling have provision for it, notably transmitting tubes and the like.
  17. THB_bassman


    Oct 11, 2005
    six of one and half-dozen of the other, as if it was blowing the stench to the front from the back. It would still end up in the front grill.
  18. THB_bassman


    Oct 11, 2005
    If you say so, that's all I need to hear. Thanks.
    A man who represents Ampeg has spoken...