GGG 60's Boutique Fuzz w/ Voodoo Labs Pedal Power 2

[sixstringphil]

Just finished the GGG Late 60's Fuzz Face with PNP Germaniums from Small Bear. It's the first FF I've EVER had in nearly 20 years of playing, so I'm trying to get the feel of it. I understand that this particular version of the FF uses Positive Ground, right? Well, I assumed I would need an adapter cable for my Voodoo Labs power supply. When I called, the lady asked me if I needed Positive Center or Reverse Polarity. Are those not the same thing? And do I even either for this pedal? The regular cables work fine, as long as I'm not damaging anything. I've read ALOT on here about this, but I'm still not sure I've got a good grasp of it. Thanks!

[petemoore]

  You don't want to reverse the supply polarity to your FF circuit.
  However you've powered it to make it great sounding and all, make sure any applied power follows the polarity of past good results.
  Or...figure out the polarity, then apply power.
  Reverse protection diode only mentioned, because once it is succesfully 'PP II'd' [powered with correct polarity using a Floating DC source], it should be zero maintenance.

[sixstringphil]

So although it is positive ground, I still would use a center-negative power supply? (as long as it has isolated grounds)

[SteveB]

You are using one of the cables that came with the power supply, & it works to power the fuzz? It sounds like the power supply jack on your fuzz is wired with a positive center. That's how I have mine wired so I wouldn't need any special cables. The only downside of is your battery will run down if nothing is plugged into the power supply jack. On the other hand, making your own power cables is super easy, too.
Steve

[sixstringphil]

I'm using the standard black cable that came with it, the same one I use for every other pedal I have. (standard boss style)
I used the layout on the GGG page, including the DC jack wiring.

http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_b69.pdf

[azrael]

You'll need one of the white cables from here:
http://www.voodoolab.com/cables.htm
The "Reverse Polarity". The GGG boutique fuzz is essentially a Fulltone '69. You'll notice the '69 in the list of pedals that need a "Reverse Polarity" cable.

[sixstringphil]

Yes, I saw that in the manual, but why would the black cord be working if I needed the white one? Am I hurting anything? Not trying to be difficult, just trying to better understand what's going on.

[sixstringphil]

Let me attempt to better clarify my thoughts:

Here is what I understand so far..
(Please correct me if any of the following statements are wrong)

1. This circuit utilizes a positive-ground due to the PNP transistors
2. The input jack is wired so that the center pin goes to the board's 9v, and the sleeve goes to the ground.

Therefore, a negative-center power supply should still be used.
(such as any boss style psu, including the normal black cord that comes with the Voodoo Lab PP2, so long as there are no negative-ground pedals daisy-chained on the same supply)

So what is the white cord offered by Voodoo Labs and why does the Fulltone '69 require it?

[azrael]

Oh, the standard one is working? That's odd.

1 - Correct.
2 - No, in the GGG diagram, that lower lug is going to ground, and is connected to that center pin.

[petemoore]

1. This circuit utilizes a positive-ground due to the PNP transistors
  Everything polarized in the circuit has to follow suit. Indeed this layout looks to be +Gnd./PNP orientation.
2. The input jack is wired so that the center pin goes to the board's 9v, and the sleeve goes to the ground.
  The PPII as you know has black cables, and mine came also with black/orange ones which flip the polarity.
  You have an opportunity to flip the polarity at the DC input jack also.
  Follow the layout exactly, then, DMM in beep mode, chosen PP II cable plugged into the DC jack, test continuity from the end that would stick in the power box, sort out that you will indeed have the more + pole connecting to Gnd.
  Reversing can cause component damage, although there is a RP Diode [D3] which should hold off the reverse current and provide Reverse Protection. That and an LED, though I like to use the above methods, can let me find which PP II cable to choose, establishing correct polarity quickly and 'dirty like'....plugging a long sleeve of 1/4'' mono plug into the input jack to switch the PS of the stompbox on, then plugging powered DC plug in the jack, instantly hitting the stompbox switch, pulling the DC plug back out.
  This gives hopefully just enough time to either light the LED or warm [not fry] the diode a little bit.
  Therefore, a negative-center power supply should still be used.
  The circuit has DC blocking caps, The PS potential is contained in the circuit except where you connect it otherwise [like ground, which has no DC blocking or it wouldn't be Gnd]
  The PP II's outputs are floating, there are no ground connections when you plug a cable into any of the 9v or adjustable outputs.
(such as any boss style psu, including the normal black cord that comes with the Voodoo Lab PP2, so long as there are no negative-ground pedals daisy-chained on the same supply)
  Polarity is what matters. Everything else should be DC blocked or floating except the instrument cables which establish 'the' ground.
So what is the white cord offered by Voodoo Labs and why does the Fulltone '69 require it?
  This, and the power supply polarity should be perfectly clear and understood before applying power for more than a second or two...I say that loosely because I've tried it numerous times and haven't blown an RP diode doing it yet, YMMV, repeated attempts to break through a RPDiode barrier may tend to limit it's reverse protection capabilities as I understand it.
  Best business is to sort out what isn't correct before applying power, especially for first power ups, no RP diode etc.
  Grab a battery and see the polarity sign on the DMM set to appropriated DC Voltage.
  Use the DMM's polarity sign to help you sort out the difference between the _/+ poles of PS by doing comparitive studies, use a battery to establish that the leads are correct [red = pos, black = neg].
  Find the black white or other [9V battery clip simplifies matters actually], PPII supply cable provides + where you need + to go to Gnd.  Use the DMM to establish that + goes through all that stuff...the cable, DC jack, internal wiring, to board Gnd. by using the beep mode. Repeat same measure for V- supply.
  Also test that non-continuity between +/- before is established at all times before and while applying power.

[sixstringphil]

Here's what I got back from Voodoo Labs tech support...

"I had our tech look at your drawing. It appears as if your pedal is center negative. In the B1 square, if the wire that is connected to that negative is connected to the center pin then your pedal is center-negative. If the wire that is connected to the positive is connected to the center pin then your pedal is center-positive. "

So I'll just keep using the center-negative cable with my PS. Too bad I mis-labled the graphics on the box to show center-positive!! Time to get out the sander!

[azrael]

Interesting! Well, I have a Pedal Power II, and a GGG Boutique FF, but have never used the FF without batteries. Just because I haven't properly assembled my pedalboard.
I have wired the GGG version with some small modifications, including power filtering and reverse polarity protection, so I believe I can attempt this without and fear of blowing anything.