18V nightmare!!!

Discussion in 'Effects [BG]' started by Antipodean, Mar 8, 2014.

  1. So I went out and bought me a new Pickle Pie B to add to my pedal board.
    Sounded awesome in the shop, so was looking forward to placing in my rig.

    My effects board consists of a bunch of 9V powered pedals, and an 18V MXR Flanger. All pedals running off adaptor &/or daisy chain.

    I always check the adaptor before I plug it in, but had a brain fail and plugged all my 9V pedals into the 18V adaptor. Suddenly a bunch of my pedals started flashing on and off.
    I realised what I had done, then switched to the 9V. Same thing - pedals flashing on and off by themselves. There was no manual on/off control.

    I though I had just fried about $AUD1,300 worth of pedals! Nothing worked, but I was given some hope by the fact that the Pickle Pie B would switch on and off.

    So I pulled apart my board and tested each pedal, one by one.... and these are the results:

    3Leaf Wonderlove - ALIVE :D
    MXR Bass Compressor - ALIVE :D
    tc Polytune Mini - ALIVE :D
    Wren & Cuff Pickle Pie B - ALIVE :D
    MXR EVH Phase 90 - ALIVE :D
    Boss LS-2 - ALIVE :D
    Boss BF-2 - DEAD :(
    Mooer Eleclady - ALIVE :D

    That's right, only one pedal died after being fed 18V!
    I don't know if the other pedals may have a shortened life, but the all work properly right now.

    That was a pretty scary moment.
    Just thought I'd share that there seems to be some sort of overvoltage protection in modern pedals.

    And yes, I'm aware of the fact I have/had 3 flangers.... :help:
  2. RIP BF-2, we barely knew you. :bawl:
  3. some analog pedals can tolerate higher voltages ok. I wouldn't recommend doing it, but usually in simpler, and usually analog, effects the transistors and resistors can stand the voltages no prob, it's the caps that are usually only rated @ 16v. In effects with voltage regulators, ICs, etc you have the potential to cook something if the voltage rating for a component isn't high enough. For instance, a 5v regulator can tolerate 9v, but 18v will over heat it.

    As for making the mistake, don't worry we've all done it. I have two effects on my board that are not 9v. I color coded the end on the power plug to correspond with the color of the pedal, making it harder to plug the wrong thing in.

    If you're electronics savvy, I'd pop that thing open and try to find out what went bad. In a case of voltage overload like that, you have a good chance that the suspect component is visibly burnt and easy to find. If you're not good with electronics, sell it on ebay as for parts and buy a new one.
  4. negativefx

    negativefx complete hack

    Feb 18, 2013
    Fort Collins
    Diodes and caps are usually the first to fry and damaged ones should be easy to visually locate.
  5. Joeynone

    Joeynone www.facethekingband.com Supporting Member

    Aug 2, 2011
    Long Island, NY
    Blew up my micro pig doing that. :(
  6. johnk_10

    johnk_10 vintage bass nut Supporting Member Commercial User

    Feb 16, 2008
    Thousand Oaks, CA
    John K Custom Basses
    the BF-2 has a 7805 5V regulator connected directly to the 9v supply. my guess is that you fried it, but it should be a simple fix.
  7. 7805 chips regulate 6.5V to 35V inputs. The only way you are going to fry one with 18V is if the heat is too much for the heatsink to dissipate.
  8. johnk_10

    johnk_10 vintage bass nut Supporting Member Commercial User

    Feb 16, 2008
    Thousand Oaks, CA
    John K Custom Basses
    a 7805L has a TO-92 case and IIRC, in that pedal it doesn't have a heat sink, but yeah, it's still supposed to be able to handle 35V.
  9. TaySte_2000


    Jun 23, 2001
    Manchester, UK
    Endorsing Artist: Mojohand, Subdecay, Overwater, Matamp
    Ditch the 18v and add a diago voltage doubler on the 9v chain and avoid such mistakes in the future
  10. boomertech

    boomertech Frank Appleton Supporting Member Commercial User

    Apr 8, 2009
    Syracuse, NY
    Designer/Owner of FEA Labs
    Here are four components (that I can quickly identify) in the BF-2 that may have failed with the 18V supply. These components are before the voltage regulator, so they are not protected by the regulation.

    D1 is an 11V zener diode, its only current limit is the 56ohm resistor used in the ground path from the power jack. I would check here first.

    D10 is a signal diode (similar to a 1N4148) that is in series with the 56ohm resistor in the power jack ground path. Excessive current can easily fry these guys.

    C39 is a 100uF 16V filter capacitor. It would have seen the bulk of the 18V, but they are usually tolerant to brief over-voltage.

    C25 is a 33uF 6.3V capacitor. It would have seen about half of the 18V.

  11. Hmmm, so it's only a few components that may have been killed on the BF-2?
    Shouldn't be too hard to fix, I guess.
    I've had a look, and I can't visually identify anything burned. I'll have a look to see if I could possibly attempt to repair it myself.

    I've also sent emails to the manufacturers (MXR, 3Leaf and Wren & Cuff), and replies are encouraging.
    The MXR pedals have a protection circuit, Pickle Pie B can handle an 18V mistake (but apparently not continuous), and Wonderlove can apparently run at 18V.
    This could explain why it was only the "vintage" pedal that died.

    As a side question, is it possible to do non-fatal damage from over-voltage? Or is it a case of "if it works, no damage done"?
    The Pickle Pie B sounds noisier that I recall from testing in-store before buying (and bringing it home and subsequently torturing it). Kinda like a crackling sound on top of the expected buzzing of a fuzz pedal when no playing.
  12. bongomania

    bongomania Gold Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    Yes, it is certainly possible to do non-fatal damage. Components can have a shorter lifespan, or their performance can be affected.
  13. Well, after realising it could be a number of different components, and the fact I don't own any soldering equipment, I figured it would be best to take the pedal to someone who knows what they are doing in order to diagnose and fix the BF-2.
    Turns out it was just one fried diode - easy fix! Though the diode did not visually appear to have been fried.
    Repair cost was less than buying a "new" one and selling the dead one for parts, so that's some relief.

    So I now have my BF-2 back on my board!

    Incidentally, I have removed the MXR Flanger (the only 18V pedal I have), so the chances of overpowering as back down to 0%.... for the moment.
    And I'm back to only 2 flangers.... for the moment.

    Oh, and according to the reply I got from tc electronic about the overvoltage issue, they said I got lucky that no damage occurred to the Polytune Mini. No protection circuit?
    Boss said that the LS-2 has a voltage protection.
  14. alec


    Feb 13, 2000
    Perth, Australia
    Happy ending!