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Carvin b1500,no signal.

Discussion in 'Amps and Cabs [BG]' started by cavedweller, Oct 7, 2013.


  1. When I turn on my b1500 the light comes on but absolutely no sound. I have checked all cables and run other heads through the same cab and they work. The amp is clean and not used a lot. Any help would be appreciated. Thanks.
     
  2. 5port

    5port

    Oct 14, 2009
    LI,new yawk
    "not used a lot"

    First step clean the effects send/return jacks with contact cleaner.
     
  3. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    or just link the pair with a signal cable.
     
  4. The amp is clean, no corrosion. Just opened it up and went through it with a knowledgeable friend... he was stumped. all connections were good and nothing burnt, clean as a whistle. I will check in to see if there are helpful suggestions. If not, to the shop it goes.
     
  5. LiquidMidnight

    LiquidMidnight

    Dec 25, 2000
    I'm not sure if the B1500 has ribbon cables or not, but the B2000 has ribbon cables that may become loose over time from travel and vibration. If you didn't check those, you may want to pop the amp open again and see if any of them are loose.
     
  6. BTW unless you have microscope vision you will not see the fretting on effects return jacks or ribbon cables. :)
     
  7. Luckydog

    Luckydog Supporting Member

    Dec 25, 1999
    Well, clearly a zombie thread, but no indication you found the problem, so...I had same thing happen at a show with my B1500. Had it hooked up to NV215 with 1/4 to 1/4 speaker cords with speakon adapters.

    Changed out the speaker cables. No fix.
    Changed out instrument cable. No fix.
    Changed out the power cables...even though I was getting lights. no fix.
    Changed out the B1500 for my Shuttle 9. No fix.
    Changed out the NV215 to two BE S15d's. No fix.
    Stumped, I finally checked the speakon to 1/4" adapters. One was bad. Its was one stinking little speakon adapter.
     
    maestrovert likes this.
  8. Dont use adapters. They are no better than just using 1/4" cables.
     
  9. Luckydog

    Luckydog Supporting Member

    Dec 25, 1999
    I realize the weak link in the chain thing. In my situation, I bought a shuttle and it only had speakon connections on the back. My other amp heads have either only 1/4 inch jacks, or the option of 1/4 or speakon. I dont want to buy multiple speaker cable types since I change cabs and heads occasionally, so I use the speakon adapters. Yes I know I dont get the power capability of speakon by doing this, but I only use them because of the GB head limitations.
     
  10. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    Some GB heads, like micros from other manufacturers, are permanently wired in bridge. Using a 1/4" phone cable is dangerous both for the amp and for you personally. If your cabinet only has phone jacks replace them with a 4pole speakon socket. It's a simple effective modification.
     
  11. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Correct, SpeakOn is not a limitation. On many amps it's required to meet safety requirements imposed in many markets and in reality is a much better, safer connection. The Shuttle9.0/9.2 can swing over 100 volts peak, well in excess of what's safe without touch proof connections. The industry is well into migrating towards SpeakOn as the standard. Because of our GB legacy from the pro audio market, we lead the change rather than following like sheep.

    Most legacy cabinets can be easily modified to accept a SpeakOn connector in place of the 1/4" jacks.
     
  12. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    Did you clean all the jacks? You should. I use a .22 caliber bore brush and Caig DeoxIT. Even if you can't see any corrosion, there may be enough in the jacks to cause the symptoms you describe.
     
  13. Faulty mute switch? Give it 20-30 jiggles and see if you get anything from the speakers.

    Also, plug directly into the Effects return jack - bypassing the preamp section...anything?
     
  14. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    You can not clean the effects return jack's switch with a brush, it's located competely out of reach. THe DeOxit alone breaks the oxide-sulfate surface barrier. You do not want to do anything to damage the plating on the jack contacts.
     
  15. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    .. but ... but ... it's a nylon brush ...
     
  16. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    The brush can't reach the switch, that's mostly what I was getting at.
     
  17. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    To test for the above, link the send and return with a signal cable. If the amp now works as it should the normalizing contacts are corroded. If you wish use a short cable, like those for linking effects pedals together, and just leave it in place.
     
  18. I took it in to my repair guy a while back, if I remember right, he said the problem was caused by over spray of the black paint on to a connection at the factory. Was weird because it worked for a while then quit. Seemed strange to me but I trust my repair guy and he fixed the problem, runs flawlessly now.
     
  19. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    I see. I'm just thinking about corroded contacts in the jack.
     

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