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?The difference between DI and Preamp(for bass)

Discussion in 'Effects [BG]' started by audioripple, Oct 11, 2004.


  1. audioripple

    audioripple

    Oct 8, 2002
    For bass
    I know the DI is used to match the impedance. a high instrument singal to low mic singal, so the low and high frequency of the bass guitar can't lose and we can adjust the gain or volume with the DI.
    And the preamp? make the level up? Colour the sound?
    Can anyone tell me?

    I decide to buy a DI + preamp to record bass.
    I consider: 1, Radial JDI + D-tar solotice(or another preamp)
    2, Avalon U5
    3, Demeter VTBP-201S

    Thanks!
     
  2. Droog

    Droog

    Aug 14, 2003
    PDX
    A DI box changes your high impedence, instrument level bass signal to a low impedence mic level signal. This allows you to use a microphone preamp to boost your signal to balanced line level. This is what amps/recording devices want to see.

    An instrument pre-amp (not to be confused with mic pre-amp) takes the high impedence instrument level signal and balances and boosts to line level. Once again this is what your amp or recording devices is going to want.

    If you want advise as to what to buy. Listen to all the different set ups. Each of the options you listed will give way different results. The U5 actually does double duty. You get a line level out as well as a Mic level out. Avalon makes solid stuff, but make you sure you listen to whatever you are thinking about buying.
     
  3. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    There are two types of DI's: passive and active. Nearly every DI on the market is an active DI. An active DI is a preamp.

    Given this, you select what you want by sound and features. Determine what features you need and then narrow down the preamps and DIs based on your needs. After you have a set of products that do the job, try to find a way to listen to them.
     
  4. audioripple

    audioripple

    Oct 8, 2002
    My gear: Fender delux Jazz bass with lace sensor pickup.
    Bass DS-2, EBS multicomp
    Record : Tascam U428 audio interface, Nuendo

    :crying: It's difficult to listen to the set up, because there are no the unit that I want in my local area. I am in shanghai, China.

    I play jazz,fusion. So I want the smooth ,warm and punch(sometimes) tone.
     
  5. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Are you looking for something to gig with or something for recording? Based on your last statement, I'd think that a good tube preamp would be ideal for you.
     
  6. I'm not very familiar with the Tascam U428 audio interface, but if it has 1/4 inch inputs like the ones on your amp, plug your bass straight in.

    Somebody correct me if I'm wrong, but because it's an active bass with a battery (active preamp) it's already a low impedance signal and there might be enough juice (voltage?) from the preamp in the bass to drive the recording input.

    I do this with my Ken Smith, bass & treble almost (9 out of 10) full boost.

    Also, with your gear listing, do you have an amp? I can run a line from the FX send on my SWR SM 900 to drive the 1/4 inch input on my Steinberg 24/96 sound card, plus I get the tube sound, EQ and Limiter.

    Make the gear that you have work for more situations (can you tell I'm broke). :)
     
  7. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Yes, generally active basses can be taken straight in to a board, but often times you will find that the sound is too hi-fi and you won't like it. A good tube preamp will add warmth without destroying the signal.
     
  8. audioripple

    audioripple

    Oct 8, 2002
    Big Benner:
    I don't like the sound plug the bass onto the interface like xyllion said. So I posted the thread.

    xyllion:
    I think it's mainly for recording, it's better that it can do best for gig.

    I also think of the tube preamp, but too many choice. I am lost! :confused:
     
  9. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    There are a ton of choices. What sounds good to one person doesn't necessarily sound good to someone else.

    Most people will agree that the higher priced preamps sound the best. Kern, Demeter, Alembic, Read Custom, and Aguilar all have excellent reputations, but all sound a tad different from each other.
     
  10. audioripple

    audioripple

    Oct 8, 2002
    Yeah!
    Maybe there are expensive to me.
    U5? or Ditto? :confused:
     
  11. jondog

    jondog

    Mar 14, 2002
    NYC metro area

  12. I'd second that thought. Try it and see if you like it.

    Basstasters is great for getting a feel for each preamp,... if you have the money to buy them. :smug:

    I tried something different last night. Had my Ken smith with full bass and trebel boost into the passive gain on the Tube preamp of my SWR SM900, then into the sound card. It had this nice, spongy feel to it,... I guess the tube slighty compressing the sound. Perhaps you could try that with your MultiComp?
     
  13. audioripple

    audioripple

    Oct 8, 2002
    Thanks!Everyone。
    I think i want a DI/preamp. Maybe I will rerocd guitar or other for my band. :)
    I have listened the sound sample from the basstaster. I like the kern. It's sounds vintage,warm,smooth.But too expensive to me. The U5 is good,too. In fact there are not lots differecne between the units. Maybe the mp3 format,
    maybe the recording.
    Too many things, it make me lost. :confused:

     
  14. Droog

    Droog

    Aug 14, 2003
    PDX
    Not that this makes much of a difference, but an Active DI is not a pre-amp. No amplification takes place in the DI process. However most of the fancy DI out there have pre-amps in them. ie Avalon and Groove Tubes. Traditionally a DI is just a little box that you plug your Hi-Z signal into and you get a Low-z mic level signal output. Active refers to the fact that its needs power (9v or phantom), passive DI's do not. If you go to your shop and ask for a DI they will probobly point you towards one of these boxes. I am partial to the CountrymanType 85, Whirldwind makes a nice boxHotbox.

    Chances are if you go looking for a pre-amp you are going to come across theU5 or the Ditto Box but keep in mind a DI is not a pre-amp.
     
  15. audioripple

    audioripple

    Oct 8, 2002
    preamp make the signal bigger, right?
    If a DI box have the gain or level knob, so it works like a preamp, right?
     
  16. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Yes, that is exactly right.

    Active means that the device has an active circuit in that requires power. Whether it is unity or lot's of gain, it is still an amplifier circuit. Active DIs and preamps both use active circuits. There is no difference at the circuit level. At the marketing level, the name DI is reserve for simple box that offer few if any controls. Preamps on the other hand are designed to provide enough amplification to drive a power amp. Some DIs also have this ability. Preamps usually have tone shaping controls where DIs generally do not.

    But keep in mind, internally both devices are amplifiers. If you only seek to get a signal to a mixing board, then either device is capable of that.
     
  17. Droog

    Droog

    Aug 14, 2003
    PDX
    That is the main difference between DI and Pre-amp. Like the name implies a pre-amp amplifies the intrument level signal to a line level signal, which is what drive power amps. A true DI actually drops the level of the signal to mic level, which is lower than instrument level, but it balances the signal for long runs and the use of Mic-pre's. Try driving a power amp with a mic level signal, it does not work for sh**. Signal is way to weak.

    However as was pointed out earlier, most of the boxes you are interested in (avalon,dittobox...) provide both abilities. Yes its a DI as it provides a mic level output, and yes its a pre-amp as it provides a line level out, but don't mistake those two outputs as they are way different signal levels.
     
  18. audioripple

    audioripple

    Oct 8, 2002
    Thanks a lots!
    I understand all! :hyper: