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Furman voltage regulator problem... I think

Discussion in 'Amps and Cabs [BG]' started by Hollow Man, Jan 26, 2006.


  1. Hollow Man

    Hollow Man Supporting Member

    Apr 28, 2003
    Springfield, VA
    Okay, several months ago, I found a used Furman AR-117 voltage regulator for sale, and I figured that it was worth the extra bucks to know that I'd always have the line voltage that I need to run my gear. Bear in mind, this isn't just a power conditioner... it's a true voltage regulator. I've been using it for a while, and when my gear is connected to it at home, I get these random VERY loud pops through my cab... kinda like when you pull the jack out of your bass while your amp is on, but again, VERY loud and VERY sharp. These pops are intermittent... anywhere from one every five minutes to one every half hour. I've noticed that when this happens, the voltage LED's that show what the input voltage into the Furman is flicker a bit, like the signal coming from the wall is dropping out and then coming back in.

    What worries me is that it seems to me like if it is in fact a drop in wall voltage that's causing this pop in my speakers, the Furman should be protecting me from this. I understand that there's a minimum voltage necessary for the Furman to be able to generate the ~120VAC, and if the wall voltage is dropping below that, maybe it would make sense. But none of my other electronic equipment (TV, computer, clocks, etc) ever have any type of problem with power cutting out. Also, I've never noticed this happening when I play in other places (other people's houses, clubs, etc). I'm sure something's wrong with the circuit in our house, but my question is, should the Furman be protecting me from this pop? It's very loud, even when I'm not playing loud, and I'm worried about my speakers. I'm also worried that this might be a sign that the Furman isn't working at all, which of course offers zero protection. Do you guys have any idea what might be going on? Also, does anyone know a good way to get Furman products inspected/diagnosed?
     
  2. Maverick Blues

    Maverick Blues Being a Thumper is all about ATTITUDE!

    Apr 28, 2005
    Richmond, VA
    Sorry to hear you're having problems, Hollow.

    First thing I'd try is to not plug your gear into the Furman (but still have it connected and on). You say you get a pop every five minutes to a half hour? Keep an eye on the readout and your ears open while you're practicing for a while. See if the pops go away but the readout still changes "on schedule."

    If you still get the pops even not plugged into the Furman, try turning the conditioner off (or unplugging it), and practice some more. See if you still have the pops.

    Where I'm going with this is, it might be the AR-117 that's CAUSING the pops.

    You said you bought it used... there may be a reason it was up for sale. Not everyone's sparklingly honest and sometimes people sell off gear because it has problems... without admitting said problems.

    I'm not sure of the topology of the Furman, but some line regulators use a switched transformer arrangement. Line voltage droops a bit, the conditioner switches to a different "tap" on the transformer to boost the voltage back up. It's a small increment, but a discrete increment nonetheless. If the switching isn't working correctly, you might be getting a spike or dropout. Or it could be a totally different approach, but still be having some problems.

    Anyway... if you don't remember ever noticing this before, the first thing I'd suggest is to eliminate the Furman as the culprit.

    Keep us posted, eh?

    'rick
     
  3. I had the same problem too with a combo amp I plugged directly into the wall...keep me posted Im pretty confused about this too
     
  4. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Quite right. The transition should be silent and seamless, so chances are quite good that something inside isn't right. You should ask someone at Furman.
     
  5. Hollow Man

    Hollow Man Supporting Member

    Apr 28, 2003
    Springfield, VA
    Great post, Maverick. There's a lot of good information and suggestions there. I will definitely try the "plugged in but not plugged into" test with my amp and Furman. I understand the concept of the transformer switching, and I acknowledge that it may not be a true seamless transition, but a pop of this magnitude is definite cause for concern. I wasn't sure if anyone here knew of anyone at Furman who could help... I have no qualms about contacting the company, but sometimes it easier if you know someone there, just for the personal attention, especially since this is a long-since discontinued model. Thanks for all the help thus far (although please keep the advice coming), and I'll report back after my tests.
     
  6. Maverick Blues

    Maverick Blues Being a Thumper is all about ATTITUDE!

    Apr 28, 2005
    Richmond, VA
    Oh, there's definitely something bad-wrong going on there, for sure! "Seamless?" Maybe not. But the "seam" should be so small as to be inconsequential... otherwise there's no point in having the power conditioner in the first place. :) I was just theorizing on a possible mechanism for the pops, is all... sort of trying to justify my suspicion of the Furman. (Keep in mind, I don't even know if that's the topology they use.)

    And, um, nothing personal there, buddy... but unless you get your wiring problems squared away before then, if the next VA/DC/MD GTG is held at your place I think I'll leave my rig at home! :D

    'rick
     
  7. The Furman does NOT use transformer switching. It uses a rectifier/inverter method. It sounds like there is something wrong with yours, not necessarily your wiring. +1 that someone may have unloaded a lemon on you.
     
  8. Maverick Blues

    Maverick Blues Being a Thumper is all about ATTITUDE!

    Apr 28, 2005
    Richmond, VA
    Cool. Thanks for the info, PBG! :)

    'rick