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What would you like in a 5-string fretless? (What I think I know)

Discussion in 'Pickups & Electronics [BG]' started by wallygoots, Feb 21, 2021.

  1. wallygoots


    Feb 16, 2021
    Hello folks, I know more about wood than electronics. I am looking for suggestions on how/what to wire. What I've got so far is a maple and ipe neck blank (yes the maple is wide on one side until trimmed down), figured maple top plate, walnut body blank with ipe laminate between the top plate and body, closeout hipshot tuners ($78), and used passive EMG 40HZ pickups ($53). The plan is a fanned fretless with 36" B and 34" G. Ebony fingerboard is on the way ($30). I'm keeping price reasonable. Here's what I think I know about electronics: 1. basically all pickups are passive, but some are paired with pre-amp in the pickup itself and are called "active." 2. If I want an active/passive bass, I need to pair passive pickups with a separate pre-amp and wire to bypass the pre-amp. 3. The battery still drains in passive mode and disconnecting the battery can cause pops that could damage ears or electronics.

    The problem is I don't know how the components actually work, so in my mind I can see a three-way mini-switch to go between "off" (disconnected battery when bass is unplugged or stored)/passive/active modes, master volume, blend between pickups, and tone (mid-rolloff?). I don't have to achieve these goals, it's just what I envision in my ignorance. What would you want, ideally, and to function with a project budget?

    I found TONE MONSTER SEB2-ABPA+ Guitar Bass Preamp Active Passive 4 Potentiometers on ebay for $77 that is close-ish. It appears to have treble/bass, active/passive volume (push/pull), passive tone, and balance. I messaged the seller and he said it's not compatible with EMG quick connect or I'd have to remove the quick connect and get an EMG wiring diagram. The used pickups I have are just wires at one end, so I'm thinking this could work if I ran the wires correctly, but the seller didn't want to promise anything. A pre-wired solution maybe makes things easier, but I'm not sure I can't just get the components myself and wire to my liking if I learn a little more.

    I found this thread helpful in how to wire an active/passive switch, but it doesn't show the whole chain. WalterW posts the correct wiring for true bypass so the preamp signal goes to ground when not in use and is therefor quiet? Looking for a wiring diagram for Active/Passive switch.

    I don't know if it's allowed to put in external links, but Tone Monster also has a SEB2-B with preamp, vol, bal, treb, and bass pots. Can I just wire in a switch for active/passive? But where in the chain? Seymore Duncan has a blog post on this, but I can't follow with my level of knowledge. https://www.seymourduncan.com/blog/tips-and-tricks/hot-rodding-the-stc-preamps

    I read about the Glock 2 band. Runs about $160 which is pricy for me and I don't know if it sets up with my pickups. And kind of a random question, but I have individual bridge parts for the variable string length. Do I have to ground all the bridge parts?

    What would you recommend? And if you have links to wiring for passive/active, point me in the right direction. Many thanks to those willing to take time to express their opinions and knowledge.

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  2. dwizum

    dwizum Supporting Member

    Dec 21, 2018
    Those EMGs will work fine with any of the preamps you've listed. HZ's are passive, and with the wiring set up like you've got it, they are as simple as any other passive pickup. The green/bare wire goes to ground and the red goes to hot. Done deal. Don't need to overcomplicate it.

    From a battery drain perspective, a typical active preamp will basically be "on" whenever there's a cable plugged in. It doesn't matter if the signal goes anywhere or not, the chip will use power whenever the cable is in the jack. But modern preamps have extremely small power requirements so it's not usually a big deal that the battery is draining when the bass is being played in passive mode, if that's your concern. And - of course - it's cheap and easy insurance to just keep a spare battery on hand.

    There are a handful of different typical active/passive switching approaches. Just find one you can understand from threads on here or elsewhere and go with it. Again, no need to overcomplicate things. You mentioned a three way switch (off/passive/active) - that would be highly unusual, since "off" is usually achieved just by pulling the cable out. You're typically only switching between active and passive with a two position switch.

    For your individual bridges - it would be typical to ground them all. Since they're close together, you can just run a bare copper wire underneath them all, between the body and the bridges, such that it contacts them all. You can also use a strip of copper tape. Or, just ground one of the bridgelets and use a brass nut to connect all the strings at the far end.
  3. wallygoots


    Feb 16, 2021
    dwizum, this is super helpful. I'm imagining an on-on 2-way flat mini-switch to go between passive and active. I'll try to find a wiring diagram for something like that. I don't know where to put the switch in the layout. Is push/pull pot more durable or desirable for some reason? The info on the bridge is also a god-send and will help me plan grounding. Thanks for taking the time to post. You didn't say what setups you prefer, do you like straight passive or active instead? I don't really understand why more bases don't seem to be have both active and passive switches. I'm sure there are quite a few opinions on the matter. :)
  4. dwizum

    dwizum Supporting Member

    Dec 21, 2018
    Push pull pots are useful because they don't require an extra hole, you can put the switching action on a pot you already have in your layout. For instance, put a push pull on your master volume pot and use the switch to control active/passive. The switch component and pot component are electrically isolated so you can use either one for whatever function(s) you want. So you get two functions with one knob. Considering that many (most?) people purchasing active preamps are doing so in order to put them in an existing bass, the act of matching the number of controls to the number of available holes in a given instrument becomes important.

    My personal preference is both, really. It just depends on the character of the instrument and what I want to use it for. That said, all but one of my current instruments are active. I don't tend to have active/passive switches on instruments because I like to just design what I think makes sense for a specific purpose rather than design for maximum versatility. But I understand why some people like active/passive switches. It's just personal preference.
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