DI on amp question

Discussion in 'Microphones (live or studio)' started by telliott, Mar 22, 2005.

  1. telliott

    telliott Guest

    Recently played a club that had a good soundman. He ran a DI box from the input of my amp. Was great the sound I got in the room and from my amp.

    Question is can that damage my amp? I know nothing about using a DI.

    Thanks in advance

  2. Tommy P.

    Tommy P. Well-Known Member

    Jan 10, 2002
    Don't worry, be happy!

    Lol, all kidding aside, it's fine.
  3. telliott

    telliott Guest

    Thanks. I heard something about phantom power and figured they all did that sort of thing.

    Too new to this to know much about more than playing my bass.

  4. Treena Foster

    Treena Foster Active Member

    Jul 4, 2003
    Tom, depending on the DI, it's just another way of getting signal either from your Amp head to the board or even your speakers.

    I use the countrymen DI...........check out this thread.........


    5_1_115.gif Treena
  5. telliott

    telliott Guest

    Thanks Treena. I will check out getting my own DI for future use. The one running on mine at the club was a Pro-C. Not sure I know much about them. I do know my SR5 had killer sound out in the room. Nothing but compliments on that sound and made a newbie bass player feel good to hear them coming in from even the other bands that played after us.

  6. Tommy P.

    Tommy P. Well-Known Member

    Jan 10, 2002
    Yes, phantom powered is a nice feature to have on active DI's. This feature saves you the trouble of plugging in a wall wart or having a fresh battery in the DI unit(having fresh batteries is still a good idea though, in case of power failure).

    Some microphones(not all) need power to operate, and most mixing boards are equipped to send the required voltage by flipping the switch called phantom.

    Since the DI's are plugged into these mixers, they can be designed to take advantage of this available power through the connecting microphone cable.

    Of course some DI's do not contain circuitry that requires power, and are aptly called passive . The internal components are usually just a transformer used for isolation purposes. There can be phase incoherency in poorly designed audio isolation transformers that would present an output not faithfull to the input. This is the tone sucking some players refer to when they say a DI doesn't allow the high quality nuances of thier equipment to sound through.

    But sometimes an unfaithfull output(such as an attenuated upper spectrum) is masking unwanted sound(like fretting noise) and is then working in a good way..., so really, there are no absolutes- just what works for you!
  7. telliott

    telliott Guest

    So will the phantom power harm the amp head in any way when applied to the input? That was my only worry. I am not sure what the max input volatage would be.

  8. Tommy P.

    Tommy P. Well-Known Member

    Jan 10, 2002

    Its just like a battery in a floor pedal. You wouldn't change a battery, or remove/insert a power plug to a pedal while your amps input is turned up - the transient pop might blow a speaker. You wouldn't plug your guitar cord into the guitar with volume up either, right?

    You only have to adhere to basic sound reinforcement proceedures with your guitar amp, or or any audio equipment for that matter.

    Power amps get turned on last...and turned off first. You wouldn't switch on the phantom power after power amps/guitar amps are brought up on-line.

    Always have your amp volume turned fully down during setup and takedown. Standby switches get engaged before showtime and during intermissions.
  9. gambit

    gambit Active Member

    Dec 14, 2000
    Bristol, UK
    Home Page:
    Behringer make a great guitar amp DI box with a built in 4 x 12 cab sim! In the UK its only 25GBP new! (US rrp is 49.99USD so 35USD street price?) Fantastic value IMHO.


    I use mine in conjunction with a THD Hotplate (using the line out) for recording. You need to EQ to get the best sound but as a quick problem solver its great!

  10. Tommy P.

    Tommy P. Well-Known Member

    Jan 10, 2002
    Nice features on that unit:

    Switchable, extremely authentic speaker simulation
    Internal battery automatically shut off when phantom power is connected
    Direct connection of amplifier outputs with ratings of up to 3,000 Watts
    Switchable input attenuation allows input levels of up to +48 dBu
    Ground lift switch eliminates typical ground loop problems
    Rugged, road-proof aluminum case
    Stackable, oversized rubber corners
    BEHRINGER OT-1 output transformer for full galvanic insulation and S/N ratio of over 100 dB
    Conceived and designed by BEHRINGER Germany
  11. telliott

    telliott Guest

    Thanks Tommy. I believe I understand it all now.


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