How much current does your bass preamp use

Discussion in 'Pickups & Electronics [BG]' started by mrbaloo, Jun 21, 2012.


  1. mrbaloo

    mrbaloo

    Joined:
    May 9, 2002
    Location:
    Sweden
    I have measured a couple of my basses. How much current does your bass(es) use.

    - Peavey Cirrus 5 FL (Made in USA): 11.21 mA
    - Peavey Cirrus 5 BXP: 4.72 mA
    - Dean Edge 4: 2.01 mA
    - Ibanez SR2010 Ashula Bass: 0.79 mA

    Please contribute to my list with measurements of your bass(es).

    /mrbaloo
  2. line6man

    line6man

    Joined:
    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    Those are rather high current draws.

    The current draw of a preamp is mainly dependent on the transistors and/or ICs used. Opamps can draw as little as 85uA. Discrete FET based preamps should draw a couple of milliamps. The current draw will increase with supply voltage, as well, as it is an Ohmic device.
  3. mrbaloo

    mrbaloo

    Joined:
    May 9, 2002
    Location:
    Sweden
    The USA Cirrus is 18 V and the rest of the basses 9 V. This particular USA Cirrus have had a broken preamp. So I replaced the OP-amp and the electrolytic capacitors. Then the preamp started be useful again. But I have no idea if the current draw is high or not. Maybe if I can replace the transistors as well (if there are anyone).

    The USA Cirrus is about 10 years old while the BXP and the Ashula are brend new. The Dean bass is about 10-12 years old.

    /mrbaloo
  4. khutch

    khutch Praise Harp Supporting Member

    Joined:
    Aug 20, 2011
    Location:
    suburban Chicago
    My Fender MIM Deluxe Jazz uses the same preamp as several other MIM and MIA active Fenders and it draws about 550 uA. My Ibanez SR505 draws about 750 uA. Both are stock.

    Ken
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  6. mrbaloo

    mrbaloo

    Joined:
    May 9, 2002
    Location:
    Sweden
    I.e. about the same amount as my Ibanez Ashula...

    /mrbaloo
  7. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    Joined:
    May 6, 2000
    Location:
    Groom Lake, NV
    Disclosures:
    Independent Contractor to Bass San Diego
    85μA.
  8. mech

    mech

    Joined:
    Jun 20, 2008
    Location:
    USA
    My old Peavey DynaBass type preamps (Dyna, Sarzo, TL-5) draw 7.5 milliamps. They are 80s tech with four NPN transistors. Alkaline battery lasts about 100 hours and slowly fades into the sunset. I've only had two die during a gig in 25 years. Active/passive switch is a good thing to have besides using it for different voicing.

    When you think about active bass current draw you have to remember some PUs are also active.

    mech
  9. line6man

    line6man

    Joined:
    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    That's what I said.:confused:
  10. TigerInATrance

    TigerInATrance

    Joined:
    Dec 18, 2011
    Location:
    NW New Jersey
    The EMG BQC on my Ibanez SR305m draws 740uA @ 18v. The OEM preamp that was replaced draws no current... You will find that it is quite dead, quite dead indeed.
  11. bassd00d

    bassd00d

    Joined:
    Feb 16, 2008
    USA Peavey Cirrus 5: 10.10 mA
    Audere JZ3 preamp: 1.66 mA

    I use rechargeable batteries in the Cirrus, and recharge them every week. Alkaline 9v batteries last me about 3 weeks.
  12. mrbaloo

    mrbaloo

    Joined:
    May 9, 2002
    Location:
    Sweden
    It is good to hear that you have similar current draw in your USA Cirrus. Though, given a standard alkaline battrey will be useful about 50 hours of continious use...

    /mrbaloo
  13. mrbaloo

    mrbaloo

    Joined:
    May 9, 2002
    Location:
    Sweden
    I have now updated the complete list:

    - Peavey Cirrus 5 FL (Made in USA): 11.21 mA
    - USA Peavey Cirrus 5: 10.10 mA
    - Peavey DynaBass type preamps (Dyna, Sarzo, TL-5): 7.5 mA
    - Peavey Cirrus 5 BXP: 4.72 mA
    - Dean Edge 4: 2.01 mA
    - Audere JZ3 preamp: 1.66 mA
    - Ibanez SR2010 Ashula Bass: 0.79 mA
    - Ibanez SR505: 0.75 mA
    - Ibanez SR305m (EMG BQC): 0.74 mA
    - Fender MIM Deluxe Jazz: 0.55 mA

    Keep measuring your basses!

    /mrbaloo
  14. SGD Lutherie

    SGD Lutherie Supporting Member

    Joined:
    Aug 21, 2008
    Location:
    Bloomfield, NJ
    Disclosures:
    Owner, SGD Music Products
    250µA That's micro amps. ;)
  15. bassd00d

    bassd00d

    Joined:
    Feb 16, 2008
    50 hours sounds about right for a Cirrus. I play at a church that has loooong services, and I don't unplug it :rollno:. It's plugged in about 3 hours during Friday service, and about 9 hours on Sunday for two services. That, plus whatever time I spend practicing during the week. So about 3 weeks of use for me, so I just use rechargeables and recharge every week to make sure it doesn't die on me...which is has before.
  16. mrbaloo

    mrbaloo

    Joined:
    May 9, 2002
    Location:
    Sweden
    In my opinion also, about 50 h of continous use seems ok and follows my experience with the bass very well.

    /mrbaloo
  17. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    Joined:
    May 6, 2000
    Location:
    Groom Lake, NV
    Disclosures:
    Independent Contractor to Bass San Diego
    No, you said 85uA, not 85μA.
  18. khutch

    khutch Praise Harp Supporting Member

    Joined:
    Aug 20, 2011
    Location:
    suburban Chicago
    If you want to be anal, then be anal: it is micro-Amperes!

    Ken
  19. SGD Lutherie

    SGD Lutherie Supporting Member

    Joined:
    Aug 21, 2008
    Location:
    Bloomfield, NJ
    Disclosures:
    Owner, SGD Music Products
    No, if you really want to be anal-retentive about it, then it should be "pedantic." ;)
  20. mech

    mech

    Joined:
    Jun 20, 2008
    Location:
    USA
    LOL. Excellent. Words mean things.

    mech
  21. SGD Lutherie

    SGD Lutherie Supporting Member

    Joined:
    Aug 21, 2008
    Location:
    Bloomfield, NJ
    Disclosures:
    Owner, SGD Music Products
    Word! lol :D

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