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Avalon U5 speaker input problems

Discussion in 'Amps and Cabs [BG]' started by BassJunkie730, Apr 23, 2005.


  1. BassJunkie730

    BassJunkie730

    Feb 3, 2005
    Brooklyn
    Hey guys and gals,

    I'm having a bit of a problem with the speaker input on my U5.

    I tried it with two different setups, the first produced no sound and the second produced sound only going to the board (not the amp's own speaker).

    First setup:

    Bass into a fender bassman 70 into an ashdown mag115 cab with the U5 speaker input connected to the second speaker out on the bassman (mag cab is 8 ohms). speaker input button is engaged. U5 connected to the PA. Result - no sound. however when I remove the cable connecting the Avalon to the secondary speaker out on the Bassman - sound returns. What gives?

    Second setup:

    guitar into a crate 112 combo. U5 speaker input connected to the crate ext. speaker out. speaker input button engaged. u5 to PA. Result - sound from PA only - when i remove the cable from the extension speaker out on the crate - sound resturns to the 112. ?

    I would really like to use this feature however why am I not getting any sound with the Bassman and PA only sound with the crate. I suspect the Bassman problems have something to do with how the speaker outs are designed.

    ultimately I would like to use the speaker input for a small wattage tube bass amp (something like 10 watts max class A with a 6550) with a load box for one speaker out and the U5 connected to the other. Then send the signal through the U5 to the PA and to my QSC and bass cab.

    Any suggestions?

    Mike
     
  2. jokerjkny

    jokerjkny

    Jan 19, 2002
    NY / NJ / PA
  3. BassJunkie730

    BassJunkie730

    Feb 3, 2005
    Brooklyn
    Yes i did. It seems pretty striaght forward. I thought that maybe the speaker input was defective but it worked with another setup just no sound from the amp cab. So why won't this work with my bassman? :(
     
  4. jokerjkny

    jokerjkny

    Jan 19, 2002
    NY / NJ / PA
    did you make sure you're not only plugging into the U5, but that a speaker cab is also plugged into the head itself? the amp head needs to "see" a load from a speaker or "dummy load", or you'll irrepairably damage your amp.
     
  5. BassJunkie730

    BassJunkie730

    Feb 3, 2005
    Brooklyn
    I always make sure I have a load on the amp so I don't damage the output transformer (even though the bassman output trans is pretty beefy). That's just the thing. I plug the amp both into the cab and the U5 speaker input (with the speaker input button engaged) and I get NO sound. however if I remover the u5 from the link (i.e. bassman into cab) - sound returns. Maybe the secondary output needs a load too. I wonder if it would work if I daisy chained the U5 off of a cabinet's parallel out (for another cab), and bypass the amp's second speaker out completely. Hmmm.

    Anybody want an old Bassman 70 that's been modded with 6550s? :bag: