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Powersoak on an SVT?

Discussion in 'Amps and Cabs [BG]' started by ThePoloHobo, Jan 9, 2014.

  1. ThePoloHobo


    Aug 18, 2013
    Tulsa, OK
    This may sound silly, but I think I'd like to get a powersoak/attenuator/hotplate, whatever its called, for my SVT. Currently my master volume never goes past 3, unless I turn the gain down, but I dont think that pushes more power to the 6550's. So I feel like even having an all-tube power section isn't really making that big of a difference. Of course it's also impossible to find one that can take more than 100 watts. So you guys know of any power soak type devices that can take this much wattage? Pointless to do for a bass amp? Or should I sell it for say a V4-b which could be powersoaked easily?
  2. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Can't do it. Even the best power soaks are rated for like 100w, and I don't know of any that can handle an SVT. An SVT will blow up either it or the SVT due to immense heat.

    V4B's an awesome head, and one of the new ones is my workhorse amp. A better candidate for a power soak for sure.
  3. Selta


    Feb 6, 2002
    Pacific Northwet
    Total fanboi of: Fractal Audio, AudiKinesis Cabs, Dingwall basses
    Two of these in parallel, if you're using a 4-ohm cab with them:

    Just keep in mind that they will get HOT, so keep flammables away and don't handle them for awhile after use. There's other alternatives, but that's the most straight forward.

    IMO, the "best" way to run the SVT is with the master dimmed at all times, and then use the gain to achieve the volume goal. This is, of course, my opinion, but I feel I got the best tone when I did this.
  4. Hi.

    IMO pretty pointless in a bass amp, but that's just me.

    Easy to DIY if You rely on the parallel cab to provide the reactive component of the load and just use a hefty resistor as the soak.
    I use a modded (4 "taps") 1KW Danotherm ZRF 55/600 brake resistor as a dummy load when repairing and benching amps.
    Easy to mod, relatively small, somewhat affordable.
    Definitely has a field day with just 300W.

    If You OTOH want a reactive 300W+ soak, you have to have a pretty deep pockets.

  5. Bassmec


    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    Rick from Sequis who make the motherload speaker simulators, will make a custom 4 ohm power soak for an SVT 300.
    I have used my Motherload dual pro 8 ohm:
    with my old blue line SVT in parallel with my Acoustic 408 cab rewired for 8 ohm.
    If I needed to quiet down the cab, I just laid it face down on a carpeted concreat floor.
    I have recorded whole albums of bass tracks in a day for bands such as "Extreme Noise Terror" like that. The motherload sounded beyond excellent and didn't get very hot really.:bassist:
    My son Robin has a vintage V4b and I love that too.
  6. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    A commercial one is expensive. You can build one for under a $100 but the amp won't react the same way as it does with speakers connected.

    It sounds like you have way too much amp for your needs. If you are considering putting a load on a 100W V4B amp, perhaps you should look for something that sounds good at lower volume levels like a 25W B-15N.
  7. I have an Ampeg V4B that I wanted to quiet down so I could put more natural tube overdrive ... The best way to get the soundI had in my head, was to turn the volume up to get the tubbey grit and use an attenuator to stop my ears from bleeding ;)

    Right now, I use a Bad Cat 'The Leash' with great results! Too bad they are discontinued :(
  8. Grissle


    May 17, 2009
    Pull a couple tubes maybe?
  9. Huh...

    The 3400W power soak I have sitting next to my desk at work says otherwise.

    Well - actually, it's 3400W without the fan running. With the fan it'll probably handle closer to 5000W.

    It isn't even ridiculously huge, ~ 18"x8"x8"
  10. Hi.

    Not easily possible with SVT and regular cabs.

  11. ThePoloHobo


    Aug 18, 2013
    Tulsa, OK
    Yeah I have decided I'm going to post it in the classifieds. But is a 25W loud enough to play over loud drums? I cant get a fender bassman though, I think theyre all too wide for my 610hlf cab.. hate the mushroom look lol. So going to get a V4-b or maybe the new Ashdown CTM-100. Cant think of any other "modern" 100w all tube heads. I'd rather not mess with a vintage amp.. seems like they break down a lot. Our guitarists' 70's marshall heads been repaired twice in the last year.
  12. eyeballkid


    Jul 19, 2009
    wes virginny
    The fender 100t has a built in power soak and can be run @ 100w, 25w, or silent.
  13. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    The new V4B is a good choice. It's well designed and well built, right up there with the best of the vintage amps.
  14. Bassmec


    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    The most reliable amps I have, are old tube amps but then I use new old stock tubes by Mullard and GEC and I have been a Marshall factory trained engineer since may 1972.
    Perhaps the bloke who fixed your old Marshall had no idea what he was doing.
    My amps have to perform every day in a busy rehearsal studio, I haven't found amps that have the power tube sockets stuck to printed circuit boards will do that, and new issue tubes are total crap!.
    If you want to see an amp that is beautifully made, wired to turrets and totally dependable you should seek an old Hiwatt or even a new or old Matamp.
  15. UncleFluffy


    Mar 8, 2009
    Head Tinkerer, The Flufflab
    Yep. Easy to DIY. I just bought a stack of 2R/300W resistors to make one for bench use. $20 each, surplus.


    or a whole lot of wire sitting around spare.
  16. Passinwind

    Passinwind I Know Nothing Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Yep, these 8 ohm/ 300 watt ones ran even a good bit less than that when I bought a dozen :

  17. UncleFluffy


    Mar 8, 2009
    Head Tinkerer, The Flufflab
    A lot less dusty than mine, too.

    8s were rare and overpriced when I went looking. Nice score.
  18. ThePoloHobo


    Aug 18, 2013
    Tulsa, OK
    Well I do believe the second time it blew was due to power surge at a dive he was playing at with his cover band, so I suppose a decent surge protector would have avoided that. Interesting though. I will look into those other amps. I just worry about reliability since I dont really have backup.
  19. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    Go to Lowe's and buy four of these water heater elements.

    On paper, 3500W @ 240V works out to (V[SUP]2[/SUP]/P=R) 16.45 ohms. The inductance is supposed to be 12.5uH. Resistance is stable over a wide temperature range. Put four in parallel and you have 4.1 ohms with a 14000W capacity, inductance 3.1uH. The inductance is so low that there is only 0.78 ohms of inductive reactance at 40Hz. Have some on order to check out the real world readings.

    ref: 1, 2.
  20. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada

    If I need a dummy load I just put one hand on each output terminal. Voila! A dummy load is created.