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.

Mike Pope's setup in BP.

Discussion in 'Amps and Cabs [BG]' started by Sufenta, Mar 27, 2004.


  1. Sufenta

    Sufenta Trudging The Happy Road of Destiny

    Mar 14, 2002
    The Signpost Up Ahead.
    According to BP, Mike Pope bypasses the preamp section on his WW amp and takes his Fodera directly into the effects return using only the active preamp on his bass. Can anybody comment on this? Will this only work (correctly) with 18v pre's? or will 9v pre's work also? The outboard/rack preamp business seems so competitive, is a separate outboard pre even necessary if your bass has a quality/versitile pre built in? Thanks
     
  2. christoph h.

    christoph h.

    Mar 26, 2001
    Germany
    he built his own preamp, an externally powered 30v unit.
     
  3. Brian Barrett

    Brian Barrett

    Nov 25, 2001
    Murfreesboro, TN (Nashville)
    Dealer LowEndBassShop.com, Builder LowEndBasses.com
    At the shop this is the only way I have for people to check out basses, unless they want to check out a pre. I use Crest power amps, which have a sensitive input and can be driven at almost full output with a 9v-battery preamp onboard. I plug people direct all the time, its one of the best ways to actually hear an instrument with out coloration. Of course the cab has some color, but I sell the Epifani's and Berg's which are a wonderful tuned cab and not so extreme as many are and have wonderful clarity while tuned for the bass and have body to them.
     
  4. Sufenta

    Sufenta Trudging The Happy Road of Destiny

    Mar 14, 2002
    The Signpost Up Ahead.
    I guess one good reason to have an outboard pre is in the event that you 1) only play passive instruments, or 2) your active onboard pre fails and you have to switch to passive (if you have an AP switch). It seems that some pre amp makers claim their product is the purest and clearest/colorless sounding. As Brian said, if you want to hear the true tone of your bass, you would want to run it straight into a power amp.
     
  5. Phat Ham

    Phat Ham

    Feb 13, 2000
    DC
    Don't forget that lots of people out there want the coloration of a preamp. Take for example the classic Ampeg sound. You're not gonna get that sound by plugging your bass directly into a poweramp.

    Also, there can be impedance mismatch problems when plugging a bass directly into a power amp.
     
  6. Brian Barrett

    Brian Barrett

    Nov 25, 2001
    Murfreesboro, TN (Nashville)
    Dealer LowEndBassShop.com, Builder LowEndBasses.com
    The idea of plugging your bass direct into an amp is to hear the bass not to get an ampeg sound. This gives you a place to build from. So often I have guys come in that have never heard their bass! Not knowing what your bass sounds like makes it tuff to know what the eden or swr, ampeg, etc. is doing to it. If your not happy with your sound, it might be your bass and it might not be your bass. That's the problem. So often people go into a music store and never have the chance to try and hear a bass with out plugging into a brand X head and cab.......

    I agree, if you want the ampeg sound then nothing better then an ampeg. But if you want to know what your bass sounds like with out it, well then.......... plug into an amp and clearer cab or your home stereo system :) !
     
  7. Phat Ham

    Phat Ham

    Feb 13, 2000
    DC
    I guess my first post came off kind of wrong. I completely understand and agree with what you have set up at your shop. I just wanted to point out one of the reasons for using a preamp.
     
  8. Brian Barrett

    Brian Barrett

    Nov 25, 2001
    Murfreesboro, TN (Nashville)
    Dealer LowEndBassShop.com, Builder LowEndBasses.com

    Cool, and agree!!

    Preamps can be wonderful for tube warmth and many other things people desire to hear or focus on.
     
  9. Sundogue

    Sundogue

    Apr 26, 2001
    Wausau, WI
    Every bass I've ever purchased was tried out without even pluggin it in.

    I usually rest my chin on the horn and play it acoustically. Only then can I try to find appropriate amplification to replicate that tone.
     
  10. Sufenta

    Sufenta Trudging The Happy Road of Destiny

    Mar 14, 2002
    The Signpost Up Ahead.
    I guess I can call QSC myself or hope Bob Lee happens onto this thread, but the whole impedance question is a bit of a mystery to me. How do you know if your onboard pre (the Bart pre on my Elrick for example) will match with my QSC power amp?
     
  11. Brian Barrett

    Brian Barrett

    Nov 25, 2001
    Murfreesboro, TN (Nashville)
    Dealer LowEndBassShop.com, Builder LowEndBasses.com
    I believe it’s a sensitivity issue with the Amp's input not an Impedance issue, but could be wrong. I've never had a problem. Rack Mount preamp's as well as floor preamps, etc. all have different output level's as well. Hopefully someone will drop by that can answer this question in terms that we all can understand.

    Plug your bass in and crank it up. If your not get much more output the sensitivity isn’t sensitive enough to be driven by the preamp. On the other hand it might work, but not drive the amp very well.
    The Crest are so sensitive that you can drive the heck out of them, but I really dig the smoothness the Crest have to them and not harsh or digital.
    Amps don’t really have a color but they can make a signal smooth, warm, digital, etc. sounding. But for testing your bass out to try and hear more of your bass then the preamp in your rack they all should get the job done better.
     
  12. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    If you have a passive bass, it'll work best into an extremely high input impedance, like 500 kilohm to 1 megohm. This is what you find in typical instrument amps or preamps.

    An active bass has a buffered output, so its output impedance is very low--much, much, much lower than that of a passive bass. So an active bass can drive into lower input impedances without noticeable signal loss. And the input impedance of most power amps, though still considered "high impedance," is still considerably lower than that of an instrument-level input: typically about 10 to 50 kilohm. An active bass should have no problem with the impedance. The main concern would be whether it can put out enough voltage to drive the amp to its full power capabilities (or at least to the extent that you need it to).

    This is one situation where an amp's input sensitivity spec is actually useful. If the bass's maximum output voltage meets or exceeds (hey, you can always turn it down) the amp's input sensitivity spec, then it it is at least capable of driving the amp to full power. Even if it doesn't, even just an inexpensive little box to provide some gain (like those made by Radio Design Labs) will make it possible.
     
  13. bassmanjones

    bassmanjones

    Feb 23, 2002
    Boston, MA
    This may be a stupid question (I know nothing of electronic stuff) but how do you determine the maximum output voltage of a bass, for example on a 9volt onboard preamp and an 18 volt preamp?

    Before I looked at the input sensitivity ratings I just assumed that the output voltage on a 9V preamp would be....9 volts. :D But, the input sensitivity on the PLX stuff was like 1 Vrms....so my reasoning can't be right.
     
  14. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    The manufacturer would be the best source if you can't measure it yourself.

    A 9-volt circuit won't be able to swing more than 4.5 volts in each direction, and probably more like 4 to 4.3 volts. And the rms value of a sine wave of 4.3 peak volts would be 3 volts.

    However, the bass's active circuitry might not have enough gain to reach that level under normal circumstances, depending on one's playing style.