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amp problem/question

Discussion in 'Amps and Cabs [BG]' started by thetaurus, Oct 26, 2003.


  1. thetaurus

    thetaurus

    May 28, 2002
    Muncy, PA
    alright...so i got my qsc rmx 1450. i have it set up for bridged use, and with the speakon wired correctly. since i'm broke right now, i'm using my bddi as a preamp. now i know they don't have enough output voltage (correct term?) to push a power amp to its fullest power, but i get enough to get by until i get a preamp. so for practice i run the power amp knob around 3 o'clock. an the bddi, i have the level all the way up, and the blend around 3 or 4 o'clock. treble is at 11 o'clock, bass at 1 or 2 o'clock, drive at 1 o'clock, and presence at 12 o'clock. this is how i like the sound the most, but at the levels we play at, i've had problems with bad clipping on certain notes. so i turned the level on the bddi down, kept the bass alittle lower, and dropped the drive alittle. this really helped, but i wasn't really as loud as i would have liked to be. so my question is this. even though the bddi doesn't have the same output voltage as say, an svp pro, could it still cause a power amp to go into severe clipping with certain settings? i'm using a passive mia jazz and an svt 8x10. anyway...let me know what you all think.
     
  2. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    The Republic of Texas
    Don't be afraid to run your 1450 fully cranked; just don't clip the power amp (or use the clip limiter) and listen to your speakers for any signs of stress (although, it sounds like your input voltage is probably too low to clip it anyway).

    The clipping must be coming from the BDDI.
     
  3. Mcrelly

    Mcrelly

    Jun 16, 2003
    Minnesota, USA
    I use an RBI with my swr 350. when I used it in the swr effects loop I can get the RBI to clip (distort) if the swr preamp was set too high. so here is what I'm thinking.... try turning your guitar down a little because you MIGHT be clipping the input of the BDDI with your guitar? then try turning up the level of the BDDI. also if your drive is set high you WILL get distortion, its designed that way. it took me a while to figure out where my distortion was occuring too!

    Just an idea

    I agree with lo-freq you should be able to leave the power amp fully cranked. if that amp has the dip switches on the back make sure they are set correctly for bridged mode.
     
  4. thetaurus

    thetaurus

    May 28, 2002
    Muncy, PA
    the switches are set correctly. it's not from my bass because it's a passive j. i know the drive will give some distortion...but that's good distortion. i'm getting "bad" distortion. like a horrible clip. it only happens sometimes. i think i'll try pushing the power amp harder, and dropping the level on the bddi a bit, and see if that helps. all in all, i just need to get the money together for an svp pro.
     
  5. 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 first thing is to determine what's clipping.

    Is the amp clipping? If so, you'll see the clip LEDs on the front panel light up. The only solution is to turn down either the amp gain or the BDDI gain, and if you can't get the sound levels you want without clipping, then you need something more powerful.

    If the amp isn't clipping, it's most likely the BDDI. The solution is to turn down the BDDI and make up for it by turning up the amp.
     
  6. thetaurus

    thetaurus

    May 28, 2002
    Muncy, PA
    yeah...that's what i figured. i used to have an rmx 850 with an svp pro. and it was great, but i felt like i was pushing the amp alittle too hard, and then i decided to try out a 400+. now i'm back to the power/pre setup. i figured the extra power of the 1450 would be better to have. i'm just waiting to get the money to pick up an ampeg pre.

    bob--just as a refresher...how should i set all the switches for bridged/mono use. i use a passive jazz bass, and only tune down a half step. this goes into an svt 8x10.

    also...does anyone have any experience with the ampeg svt IIP pre?