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DIY Stompboxes => Building your own stompbox => Topic started by: lightningfingers on April 26, 2004, 05:38:00 AM

Title: FF POWER SUPPLY
Post by: lightningfingers on April 26, 2004, 05:38:00 AM
almost done w/ my ge fuzzface, one more thing tho; its a +ve gnd circuit. how do i add a external power supply socket that stops the transistors from being fried if someone puts a plug in of the wrong polarity?
Title: FF POWER SUPPLY
Post by: Chris S on April 26, 2004, 05:50:00 AM
The Max 1044 chip will convert a positive currnet to a negative. I used this for a positive ground octave fuzz. That way I only have to use a negative ground power source for all my effects.   :D
Title: nah
Post by: petemoore on April 26, 2004, 11:57:16 AM
You're probably wayy better off NOT putting any kind of power supply on a Fuzz Face.
 I would try it before you start installing any DC connections for a PS
Title: FF POWER SUPPLY
Post by: RedHouse on April 27, 2004, 11:47:35 AM
Pete, why do you say that? not to use a PS on a FF.

I ask because I have a FF circuit on my bench currently and power it from a regulated 9v PS, I see/hear no negative issues with using it, but there might be something I'm missing in this topic.
(standard LM7809 circuit)
Title: FF POWER SUPPLY
Post by: bwanasonic on April 27, 2004, 12:58:35 PM
Quote from: RedHouse
I ask because I have a FF circuit on my bench currently and power it from a regulated 9v PS, I see/hear no negative issues with using it, but there might be something I'm missing in this topic.

Try it with a carbon battery into a tube amp and see if you hear a difference when A/B'd with a PS. The impedance of the battery is said to factor into the whole FF mojo, so even Alkaline vs. Carbon makes a difference. I don't have a PS jack on mine (Ge PNP/ pos. gnd) , so I've never tried it, but I'm pretty sure I can hear the Alk. vs. Carbon in my not so scientific tests. The battery life with carbon batts. in a FF is so long, I have found it's not worth hassling to try and get it to work with my power supplies.

Kerry M
Title: Could be Cool...
Post by: petemoore on April 27, 2004, 01:19:48 PM
I tried it with some different PS's, ...rediculous.
 Maybe I am missing something, the resistance of the battery is part of the original circuit.
 Maybe more Ppl should try it, and find out it isn't always critical about the battery resistance.
 I still recommend trying it first though,
Title: FF POWER SUPPLY
Post by: Triffid on April 27, 2004, 01:30:26 PM
I am not sure how much you have to worry about frying your pos gnd ff with negative power supply.  I think it just wont work.  I have a '69 that I didn't know what pos gnd (before I got into this stuff) and used my neg gnd adapter.  I had it plugged in for a while before I realized I was stupid.  I put a battery in and nothing was wrong with it at all?  Looking at the curcuit now, I don't think Fultone puts any special protective components in there.  

I may just have gotten lucky though :?
Title: yeah
Post by: petemoore on April 27, 2004, 10:36:34 PM
I reverse polarized lotsa GE's and Si's way back when...I have some transistors that don't work and some that make noise...I don't know exactly why...lol
Title: FF POWER SUPPLY
Post by: RedHouse on April 28, 2004, 10:11:44 PM
Ok I tried it ...in my opinion it didn't make positive (discernable) difference, slight at most, but not enough to offset the value of the PS.
(I'm using a LM7809 based PS)

I'm going with the PS on my stuff.
(I use the PNP negative ground circuit)