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Genz Benz Schematics??

Discussion in 'Amps [BG]' started by thmsjordan, Apr 15, 2014.

  1. thmsjordan


    Jan 10, 2010
    Pittsburgh PA
    Dear talkbass humanoids,

    I have a used Genz Benz 3.0 that is overheating and shutting itself down. Very abberrant behavior. I have spoken to it, punished it (Playing it through old Fender guitar cabs - just kidding) and still the problem persists. I have an excellent tech but we need schematics to service the thing. Anyone know of a source for this?

    Thanks to all talkbass humanoids, and when my species takes over your planet, I will make certain that those of you who helped will die quickly, mercifully and without pain, unlike the rest of your species.
    agedhorse likes this.
  2. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    This aberrant behaviour can be attributed to limited cooling flow. Pop the lid, amp disconnected from power of course, and vacuum it out. Pay particular attention to the heat sinks and fans. Make sure the fan is actually running.
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  4. agedhorse

    agedhorse Development Engineer-Mesa, Product Support-Genz Supporting Member

    Feb 12, 2006
    What exactly are the symptoms?

    The Shuttle 3.0 does not have a fan and is just about impossible to overheat UNLESS you have a speaker load that is less than 4 ohms (sometimes a cabinet gets repaired or modified with a lower impedance driver than stock but is not labeled... for shame) or an intermittently defective speaker cable.

    If the power amp standby LED does not turn on when you experience this, it's almost certain to be an intermittent effects loop return jack switch. Try using a short jumper between the effects send and return jacks to bypass this switch. Usually, just cycling a plug in the effects return jack a few times clears these switch contacts and you are good to go.

    There are no schematics available for the SMPS/class D module, it's considered a non-serviceable part because of the safety and EMI certifications that go along with the module as a complete assembly. It is very, very rare for there to be a problem with this part, which is why I am recommending that you look at more common causes first.

    I am always available to take care of service on your amp as well.
    FretFree likes this.
  5. thmsjordan


    Jan 10, 2010
    Pittsburgh PA

    Thanks for the reply. I wanted to clear a few things up.

    1. Cab used was a new, out of box Genz benz Focus 115. So, I am pretty certain I was running the head into an 8ohm load. For upright, it goes into a 112 neo Avatar, also purchased new, and also an 8ohm load.

    2. Bypassing the effects loop was the first thing we tried, alas to no avail.

    3. Problems experienced : The head was purchased used a few weeks ago, and used primarily for Upright Jazz/Show work though it always seemed a little on the warm side by the end of the gig. The weekend in question was the first gig on electric with this amp. (I am primarily an upright bassist - Jazz, pit work, and orchestral work. I play the electric but I leave most of that type of work for dedicated electric players, I usually get called when there is doubling, or a lot of reading on the electric involved.) We played about a 400-500 person large ballroom, and we played just standards at first. Again, a little warm by break. Second set, dinner was done and we started continuous music for the remainder of the evening as contracted. This was truly continuous. The leader would hand signal key changes and we were off and running. Volume was medium for a Jazz/Pop type casuals group. It was about 30 or so minutes into this continuous playing that we all smelled burnt plastic and the head felt extremely hot to the touch. Shortly after this, the amp would simply shut down. cycling the on and off switch would turn it back on. Thats really all I have for you. How does it sound Doc? Sounds like something serious, perhaps an entire board might need replacing due to potential heat damage. I am wondering out loud here how expensive this may get.

    I am still within my return money back window time at the store I bought it from, but fast approaching the crunch time for that. If you have any thoughts on these symptoms, I am happy to listen before I just return the thing and replace it with another unit.

    I love the upright sound this thing makes. I hate to see you guys not making amps anymore. I weep.......
    Last edited: Apr 22, 2014
  6. agedhorse

    agedhorse Development Engineer-Mesa, Product Support-Genz Supporting Member

    Feb 12, 2006
    Does sound like a failure, if you are in the US and the amp is less than 3 years old, I can take care of the warranty service for you, turnaround time is 48 hours on the repair. If not, I can still service it for you, or you can contact the seller and take them up on whatever return policy they offer.

    We have seen so few failures of these amps that frankly I do not know what the problem might be. I think I have seen one in the last year.
  7. Princedead


    Apr 21, 2014
    Hi guys,

    I had the same problem with the same amp several Times during gigs. Since i low the input gain under five the problem disapear with my active basses.

    You might do the same or buy a Shuttle 6.0 :)
  8. thmsjordan


    Jan 10, 2010
    Pittsburgh PA
    I just assumed that since it was purchased used that the warranty was non transferable. if it is transferable, I don't know the age of the amp. the S/N is 0708854 if that helps date the unit. I live and work in Ohio and in Pennsyltucky in Murca. Where the Amish have drive by shavings: http://news.yahoo.com/amish-bishop-...g-attacks-195140380--abc-news-topstories.html
  9. Red Planet

    Red Planet

    May 29, 2005
    Everywhere - All The Time
    OEM Manufacturing Supplier
    thmsjordan, agedhorse is your guy he can take care of it for you.
  10. agedhorse

    agedhorse Development Engineer-Mesa, Product Support-Genz Supporting Member

    Feb 12, 2006
    PM me and I will walk you through you getting this resolved.

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