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Power Bricks vs Power Chains

Discussion in 'Effects [BG]' started by grygrx, Dec 14, 2005.

  1. grygrx

    grygrx Lookout! Here comes the Fuzz! Staff Member Supporting Member

    Dec 24, 2003
    Columbia, MO
    I've done some reading about this stuff, but i've had a hard time finding this answer:

    Why would I want a power brick like the Dunlop Multi-Power
    or the Voodoo Power Pad (in the $100 range) vs a power chain like the Godlyke PS9($40ish) or Onespot.

    Is there an advantage that I'm missing?
  2. Jazz Ad

    Jazz Ad Mi la ré sol Supporting Member

    The Voodoo has separate power outlets to prevent ground loops.
    Others such as the Cioks or the Dunlop are all wired together internally.
    In these last units, the result will be the same as with a Godlyke or Onespot.
  3. Basstyra

    Basstyra Commercial User

    Apr 3, 2005
    CTO @ Two notes Audio Engineering
    I powered up to 9 pedals with a 1spot+daisy chain and never had a ground loop problem.

    Well, we all know Murphy's laws, yep... It's at my next gig that thoses problems will arise... Keep praying... :D

    (just kidding, I'm perfectly happy with this system)
  4. CetiAlphaVI


    May 27, 2005
    In addition to the standard 9v's, the DC Brick also allows you to power 3 18v pedals, too. I am not aware that the one spot and godlyke's have this ability.
  5. grygrx

    grygrx Lookout! Here comes the Fuzz! Staff Member Supporting Member

    Dec 24, 2003
    Columbia, MO
    So filling out my electronics idioticy... a ground loop is when "bad things" (hizz, hum, damage) because of umm.. looped grounds?

    How big of concern is this?

    I can see the 18v being nice.
  6. D.A.R.K.

    D.A.R.K. Supporting Member

    Aug 20, 2003
    the voodoo will also power line6 pedals, and has a voltage sag adjustment(a control that lowers the voltage below 9 volts because some pedals, such as a dod envelope filter, supposedly sound better with "brown" power).
  7. Jazz Ad

    Jazz Ad Mi la ré sol Supporting Member

    True, although it can easily be done using a voltage doubler device plugged on the daisy chain cable.
  8. Ground loops cause low frequency hum, they are not dangerous as such and are unlikely to harm your equipment.

    However, I have experienced ground loop hum that was damn loud, almost as loud as the bass signal itself! Admittedly this is an extreme and somewhat rare circumstance. However, mild ground loops are very common, especially where PA's are involved.

    A ground loop can form wherever a single device has two paths to ground. A stompbox is often grounded via both the input/output jacks and the DC power jack - this means a "ground loop current" can flow in the circuit formed via this path; pedal 1 output jack to pedal 2 input jack, via pedal circuitry to DC input jack, then (most commonly) via the daisy chain cable to pedal 1 DC input jack, then via it's circuitry to the output jack - completing the loop. Multiply by many pedals and other potential sources of ground loops such as amps then you potentially have a big problem.

    An isolated power supply breaks the most common loop but doesn't completely eliminate the possibility of ground loops.
  9. Get a wireless system
    And put it in the series where the loops are occuring.
    Live with it!


    PS buy the best you can afford (whatever it may be)

  10. Hmmm, are you for real?!

    Just in case anyone happens to think this is a good idea, bear in mind that this will not solve your problems because the wireless reciever itself ALSO has two paths to ground and could well be the cause of a ground loop hum and not the solution.

    I have lived with mild loops, but because you cannot always guarantee they're going to be mild when you go to a different venue, the "ignore it and it'll go away" tactic often backfires on you when you least need it.

    By far and away the best solution for pedals is to use isolated "floating" power supplys. This is where the power supplys are not connected to each other, nor to a ground reference - until it is connected to ground via the pedals circuitry. This means that the only path for ground is via the output jack.
  11. grygrx

    grygrx Lookout! Here comes the Fuzz! Staff Member Supporting Member

    Dec 24, 2003
    Columbia, MO
    So translation of this is: "Buy the wall warts for each" ?
  12. individual wall warts for each pedal is one way yes, building a Spyder power supply is another (see www.geofex.com)
  13. bass_drum


    Feb 13, 2005
    Does anyone know what he means with the numbers (DB01, 220uF, 78L09, and 10uF) seen in this diagram?


    My dad offered to build one of these and I'm just deciding between this and the one spot. I am planning on building a pedalboard much like the "Pedal Pad AXS", and I plan to space the pedals out quite a bit, so I worried about having enough space between the jacks (can you skip a jack and get more room between pedals that way or would that not work?).

    Also, what would you use to connect the pedal to the spyder?

    Would a pedal like the Boss NS-2 (or the behringer counterpart) eliminate the soun coming from (possible) groundloops?

    Sorry about all the questions and thanks in advance!
  14. They are all electronic components. The DB01 is a rectifier, the 220uF is an electrolytic capacitor, the 78L09 is a regulator IC and the 10uF is another capacitor. Someone with some electronics knowledge will be able to help you, but the associated article and others available on http://www.geofex.com are also a great help. As is http://www.diystompboxes.com.


    You just need some two condutor cable capable of handling a modest current (200mA max maybe.) You can make the cable any length and run it in any direction, so put your pedals wherever you want and make some custom cables to connect the power.

    No. All they do is mute the signal whilst your not playing. Plus, if the ground loop occurs after the noise gate, it will do nothing at all.
  15. bass_drum


    Feb 13, 2005
    haha okay thank you sooooo much!

    so I worried about having enough space between the jacks (can you skip a jack and get more room between pedals that way or would that not work?)



    I meant that with a daisy chain to get mroe space between pedals can you skip one jack on the cable to be able to space the pedals alot farther apart?

    Thanks again!
  16. Cougar207


    Jun 17, 2005
    St. Charles, MO
    Yes, they are all wired in parallel.
  17. oh, then yes, you can skip a jack.

    But be warned, using a daisy chain cable totally defeats the purpose of building a Spyder in the first place (eliminating ground loops.)

    So, use one or the other, but not both!
  18. Jazz Ad, could you please tell a bit more about voltage doubler device. I have never heard of it before. Can I buy one from music/electronics shop or do I have to build one? I guess the device is quite small. :confused:
  19. bass_drum


    Feb 13, 2005

    I understand that, I am still trying to decide between the daisy chain or the spyder. Thanks again!
  20. cool, just making sure to spread the word on that one - I'd hate for anyone to make that mistake and start dumping on the Spyder.