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  • May 23, 2009 at 1:10 am #78282
    Stormbringer
    Member

    I am having a custom pedalboard built. I have several EH effects-Original Holy Grail, the new Holy Grail Nano, Small Clone, and the Bassballs Nano. My question pertains to the Holy Grail(s). I will be using the T Rex power supply classic (blue model). The unit delivers a total of 1500 mA of supplied power through ten outputs as follows:

    Eight-9 volt DC outputs, all “sharing” the same ground with a total of 500mA
    One 12-volt DC output with isolated ground giving 500mA
    One 12-volt AC output with isolated ground giving 500mA

    Knowing that the Holy Grail is rated at 9 volt/500mA, which output should I use?
    I had (in my current powered board (same grounds) tried to use the HG with the barrel connectors plugged in with the other effects-It created this “whistle noise” digital vs analog? I wanted to eliminate having to use the AC power plug wall wart. Even though the HG is 9 volt/500mA can it be used with the T Rex in either of the 12 volt outputs? This has been somewhat frustrating !

    May 23, 2009 at 3:35 am #96945
    julian
    Moderator

    You know, it sounds like your power supply doesn’t fit your needs.

    That’s a pitiful amount of amperage for 8 9v outputs, especially shared. My power supply has 6x9V at 100ma each (isolated) for 600ma, plus 2x9V at 250ma each (isolated) for 500ma. I’m sure the HG+ doesn’t need a full 500, the HG only needs 225, so 250 would be fine for the HG+)

    There’s a great chart here listing power supplies and features. http://www.stinkfoot.se/andreas/diy/power/psu.htm

    May 24, 2009 at 9:51 pm #96983
    Stormbringer
    Member

    Are you kidding! Where are you getting the information from. THe Holy Grail (original large casing) clearly states on it as having 9v/500mA. Maybe the HG plus only needs 225mA. Thats not what I have. My question was referencing as to what output I possibly can use with the TRex power supply having a total of 1500mA. 8 at 500 total, 2 at 500ma each Which is more than plenty for my needs! Period!

    May 24, 2009 at 10:22 pm #96988
    julian
    Moderator

    HG’s power supply is 9v/500ma, not the pedal’s actual intake. It doesn’t actually need that much, the power supply just puts out that much. Generally adapters offer twice as much amperage as needed. My HOG comes with a 9LDC-500 adapter, but I power it with only 250ma.

    Even for a moderate sized pedalboard, 500ma shared of 9v is very little- especially for being shared. I’ve had noise issues with 1700ma shared. That’s what’s wonderful about isolated outputs- you can have less amperage and less noise issues. Sure you’ve got 1000 ma more, but, it’s in 12v ac and dc.

    The 12VAC would definitely fry your Holy Grail. The 12VDC I’m not sure, you’d have to find out with the EHX (staff) guys. It has to do with component tolerances. Too much VDC and you can fry your pedal as well.

    May 25, 2009 at 1:21 am #96996
    Stormbringer
    Member

    Thank you for the clarification. I appreciate it!

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