Dismiss Notice

Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Making my active act like a passive

Discussion in 'Pickups & Electronics [BG]' started by Benjamin Strange, Oct 26, 2003.


  1. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    Is something like this possible? I have some pedals that really don't like active basses; passive works much better. I'm guessing this has something to do with output impedances on the bass. Can I somehow make my setup (Steinberger equipped w/ EMGs & Aguilar OBP1 @ 18v) work better with my pedals?
     
  2. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    yeah, I had problems with my Frantone Lo-Tone running against an active bass signal.

    If you had passive pickups, you could have put in an active/passive bypass. But I'm assuming you have standard active EMG's, so that would be redundant.

    One thing that I noticed helped was turning down the bass boost on my on board preamp - it didn't overwhelm the pedal as much then.

    sorry I can't be more help
     
  3. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    I'm not sure what the problem is, but it's surely not an impedance issue.
     
  4. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    I think it's more related to having a hotter signal with an active bass. I've definitely experienced pedals that seem 'overwhelmed' by an active bass signal, so I would turn my onboard bass boost and sometimes volume down. They would then sound better.
     
  5. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    No, it's definitely not a volume issue. For instance, my FUzz Probe is supposed to squeal like a stuck pig on certain settings, and even if I turn my bass all the way down it still refuses to do it. When I unplug the bass, squeals abound.

    I'm thinking this is an output impedance issue somehow. Ernie Ball is making two new volume pedals; one for passive with 250k ohm resistance, and one with a 25k ohm resistance. I'm guessing that my pedals are only used to much more impedance, thus they act funky.

    I would go passive with my bass if I could, but I don't think you can get passive EMGs, and I think they are the only ones who make pickups that fit in my bass.:meh:
     
  6. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Ok, now we are getting somewhere. You are using a volume pedal before your effects. A 250K volume pedal is meant to be used with a passive instrument. I would get a 25k volume pedal and use it at the end of your effects chain. Do all of your effects first and then put your volume pedal in the chain.

    This actually will work better, because now your effects won't be altered when you change your volume via the volume pedal.

    BTW, as JMX said, the pedals themselves aren't sensitive to output impedance of your bass. The volume pedal on the other hand is a passive network and is sensitive to output impedance.
     
  7. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    Sorry, I was using the volume pedals as an illustration. I don't have a volume pedal.

    ZVex says on his site that his pedals don't respond well to active instruments. What gives here?
     
  8. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Consider the fact that each effects box is an active circuit. You can chain them together with no problems. Yet, you are saying that an active bass distorts through them. The only possible reason for this is that the signal out of the bass is too hot for the pedal and is causing it to distort.

    I have experienced this myself and found that if I turned down the volume knob on the bass that boxes then work. I have found mxr pedals to be this way.

    If you are happy with the bass and don't want to turn down the volume knob at the bass then here are a couple of options:

    - Add a resistor network to reduce the output volume of the bass. You can do this simply using two fixed value resistors or a small pot that you leave inside the bass.

    - Add a stomp box that works with the high output of the bass and reduces the output before going to the next pedal.
     
  9. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    This has nothing to do with volume. It has everything to do with how the pedals react to the bass. They are NOT distorting. They just don't act the way they should.

    For example: my Fuzz Probe squeals on certain settings. It's supposed to do this. Plug in the bass, no squeal, no matter what settings are on the bass or the pedal. Even with the volume on the bass off, nothing. Unplug the bass, and squeal galore. Plug in a passive bass, with volume up or down, it squeals. Therefore it has nothing to do with me overdriving the pedal with the bass, or another pedal.

    Other pedals I have don't feel right with an active bass, regardless of volume. Most of the ZVex stuff seems to dislike the active, but sound great with a passive. I know what a fuzz pedal should sound like, regardless of how hard it's being hit at the input stage.

    Another example: Ernie Ball volume pedals (I don't have one of these) have a 250k resistance for passive basses, 25k for active. If it were simply a volume problem, why would they make the pedal for passive basses with a higher resistance to them? Seems backwards. Only way I can figure it is it has something to do with how an active circuit changes output impedance in some way.

    Anybody know what I am talking about, and how to help?
     
  10. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Ok, please understand that I do know what you are talking about, but the story wasn't complete before. The Fuzz Probe is a funny pedal. I suspect that it only works correctly as the first pedal in the chain. Because of the bizarre nature or this pedal, I suspect it will only work with a passive instrument.

    The Fuzz Probe turns the instrument into a sort of antenna that is then processed in the pedal. The only way for this to work correctly is with passive pickups. Talk to the manufacturer, but I suspect that you won't be able to get this pedal to work with an active instrument.

    That said, EMG does make passive pickups. You might want to consider contacting them and see if your pickup size is available in a passive model. You can also check their web site but somethings are hard to find on it.
     
  11. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    Well, it's an odd question. Easily misunderstood. :cool:

    I've emailed EMG about it, since it effects more than just my pedals. Perhaps I will convert the whole bass to passive if I can.

    I wonder how good a passive system will sound with a Steinberger? Hmmm....:meh:
     
  12. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Steinberger eh? I have a Korean Steinberger with the Korean pickups. What size are your pickups? Are they pups in the guitar humbucker casing like mine or are they in a 3.5"x1.5" soapbar?
     
  13. Benjamin Strange

    Benjamin Strange Commercial User

    Dec 25, 2002
    New Orleans, LA
    Owner / Tech: Strange Guitarworks
    They are humbucker sized. Are yours passive?
     
  14. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Yes, mine are passive, but I don't know if EMG sells the passive version domestically or not. I checked online and they don't list a passive version of the HB pickup, but you never know. Maybe a call to them on the phone would be better.