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Outboard Pre for Passive P (<-- nice ring to it :^> )

Discussion in 'Pickups & Electronics [BG]' started by pbasswil, Oct 1, 2009.


  1. pbasswil

    pbasswil

    Feb 17, 2008
    I'm about to receive the first passive bass I've had for years, a Lull PJ5. I sometimes need to drive a lo-o-ong patch cord to my amp -- for instance I often take my bass out front to help with soundcheck. (And I don't want to deal with a wireless system.)

    So I'll need to buffer my passive signal with a preamp; but I don't want to add an onboard one to the bass -- it has to be small enough that I can velcro it to my strap. (In other words, pedals/D.I.s are out).

    The only compact outboard pre's I've seen seem to be intended for acoustic bass. For instance, Fishman has a few; their Pro-EQII and Pro-EQ Platinum Bass interest me.

    These are ideal for piezo pickups (high impedance), but the manuals claim them to be compatible with magnetic pickups. Their input impedance is 10MOhms! That's way higher than any regular bass amp's input; is that really suitable for passive magnetic pickups??

    Anyone else use something portable to buffer their passive basses?

    Thanks in advance,

    Peter Wilson
     
  2. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    alpha-music.com
    so you want a preamp that you would use at soundcheck and ditch for the show?

    a little googling found me this, and i think there are others as well.

    if you're using it for the show, it sounds like you just need an active bass, and are trying to rig one up in a more complicated and fragile way than is necessary.
     
  3. pbasswil

    pbasswil

    Feb 17, 2008
    No, I'll just leave it on for the whole gig; no sense having to match/balance the "without pre" signal to the "with pre" signal that I soundchecked with.

    Well that's an intriguing product. I don't understand how it works, since the active electronics in it "don't buffer the signal". Imagine a device claiming to greatly ease the flow of water thru a hose, without it being a pump!

    Can I ask what term(s) you searched to turn that up?

    An active bass would be simpler, but I want to use my new passive bass, the best instrument I've owned. I can tolerate the complication, as long as the pre is small and can be unobtrusively attached to my strap.

    Anybody have experience with such a small pre -- maybe one of the Fishmans?
     
  4. if it's not a buffer...it must be a boot-strapping impedance correction device similar the "redeemer"...
     
  5. Munjibunga

    Munjibunga Retired Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    Sadowsky, Aguilar and others make their preamps in stompbox form. SABDDI, Tone Hammer, BassBone and others add versatility in tone shaping and connectivity.
     
  6. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    alpha-music.com
    what the heck is a "boot-strapping impedance correction device"? i have a redeemer (built into a box wired into my repair bench test amp rig), and it's just a nice buffer.
     
  7. pbasswil

    pbasswil

    Feb 17, 2008
    Thanks, all great products, but like I was saying I'm looking for something smaller than a pedal, to velcro to a bass strap.

    So far all I"m aware of is Fishman, and also K&K, whose quality and suitablility I'm unsure of.
    I know someone out there is going to mention a small format pre that I hadn't considered yet. :^}

    - pw
     
  8. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    alpha-music.com
    then the most logical thing would be to add a bypassable preamp to the bass.
    good analogy, and i don't get it either. i was searching for "buffered guitar cables", "active guitar cables", things like that. i remember seeing ads for a cable that had a watch battery-driven buffer built right into a plug end.
    super-high 10M piezo buffers always struck me as sounding kinda "weird" with electric instruments; not an EQ thing, just a "feel" thing.
     
  9. I seem to recall I had the Fishman unit for a little while, to be used as a back up DI in case of amp failure. I think the build quality was pretty good, and it was a nice compact unit, but I returned it so I am thinking I didn't love the tone / eq.
     
  10. Munjibunga

    Munjibunga Retired Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    Oh. That's different. Never mind.
     
  11. pbasswil

    pbasswil

    Feb 17, 2008
    Actually, you made a good list of quality stompbox pre's/D.I.s; useful to have. I appreciate your input.

    - pw
     
  12. pbasswil

    pbasswil

    Feb 17, 2008
    Yup, that would be logical.
    I know it's a petty thing, but around the house, I loathe having to remember to unplug my bass to save the battery! I waste so many 9Vs, and I hate it. And I like the instrument to sit there plugged in and ready for me to play at the slightest whim.
    Say, can any onboard preamp be wired to have a bypass switch that takes the battery out of the circuit even when the jack has a cable in it?

    I know, huh? It struck me the same way. I'd just have to carefully A/B the signal with and without the Fishman, at a music store. Proof's in the pudding, as one of my ancestors used to say.
     
  13. bongomania

    bongomania Gold Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    TB'er "fdeck" makes what may be the perfect product for you. There's a link to it in his profile and sig.

    Another option would be to simply DIY a basic FET buffer and put it in a small box of your own choosing. I know many people have used Pastille and Altoids tins for small buffer housings.
     
  14. pbasswil

    pbasswil

    Feb 17, 2008
    Hey, I remember seeing that preamp when I was researching my double bass setup. Two niggles though: it's another 10MOhm input impedance device -- probably more suited to piezos than magnetic signals. Also, he doesn't ship outside the U.S. ('course that could be circumvented).

    Alas, I'm not handy that way. Nor that technical.

    Say, I enjoyed your compressor page last year, and got hooked up with my Jacques Fat Burner thru it. Now there's major chug! :^}

    -- peter
     
  15. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    alpha-music.com
    sure, you would just need a switch with a couple extra contacts to disconnect the battery at the same time it bypasses the preamp.

    the only drawback is that switching like that while the amp is on will tend to make noise from the preamp powering up.
     
  16. pbasswil

    pbasswil

    Feb 17, 2008
    Thanks Walter, that opens up another option.

    Meanwhile, I keep stumbling on various simple buffer gizmos. Doobtone Micro Buffer is a name that keeps coming up, but I'm not sure the guy is still producing them -- I can't find a contact.
    Here's another one that's available:
    http://lovepedal.com/pedals/driver.html
    ...but at $130, I find it to verge on unreasonable.

    -- peter
     
  17. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    I wonder if you could fake something like this with a DI and a mic pre. You know, devices that are supposed to be transparent. I'm thinking a small DI - Radial Pro, GT Ditto that sort of thing - then a long mic cable to a mic pre to convert back on the amp side ... I'm not sure if there is a passive box to go XLR back to instrument level in. That would be the ticket if there is ...

    If you were using an out front FOH rig, I'd say plug in at the board and then send a line down the snake back to your amp ... convert back to instrument in using a Radial X-Amp or similar.

    I'm totally with you on not wanting to muck about with your Lull. thta's too nice an instrument to mess with.

    In my circumstance I lean heavily on the FOH so my on stage setup is generally a monitor. Part of my gig is to keep it low enough that I don't drive the room most nights ...So for me I could just DI to the board and I'd be good to sound check... FWIW I've landed on the ParaDriver as working best for me these days
     
  18. bongomania

    bongomania Gold Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    Yep, Radial makes a passive re-amp box, and really most passive DI's can be run "backwards" anyway.
     
  19. yes...most passive DI's are just an impedance-matching audio transformer with a centre tap on the XLR (hi Z) side...you can run these backwards (Hi Z to Lo Z) no problem.
     
  20. no ... redeemer is not a buffer in traditional sense...

    do a search in this forum for "redeemer" look up the patent application link and observer for yourself...

    it's quite a different bird than a JFET buffer (or any other buffer)
     

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