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DIY Stompboxes => Building your own stompbox => Topic started by: Atodovax on January 17, 2018, 08:43:14 AM

Title: FuzzFace Late 60s GGG question
Post by: Atodovax on January 17, 2018, 08:43:14 AM
Hello everybody, im building the Boutique late 60s NPN Fuzzface from General guitar gadgets and i have a doubt. Is this circuit negative ground or positive ground?. I alkready have the Ge transistors and dont want to blow them up. This is the layout.
http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_b69_npn.pdf
It seems to me like negative ground, but...... Shouldt the LED there be reversed?
Title: Re: FuzzFace Late 60s GGG question
Post by: GibsonGM on January 17, 2018, 08:57:45 AM
That's negative ground, Atodovax.  If you follow the battery " - " terminal up to the input jack, you see that it goes to the sleeve and ring (which will be connected when a plug is inserted"), and to the DC jack ground.    On output jack, you see the board grounds connecting to the sleeve, then back over to the input jack ground.   LED anode (+) is facing right.

So you were right!

Welcome to the forum! 
Title: Re: FuzzFace Late 60s GGG question
Post by: Atodovax on January 17, 2018, 09:05:07 AM
Thank you very much! So i will reverse the LED ! :D
Title: Re: FuzzFace Late 60s GGG question
Post by: GibsonGM on January 17, 2018, 10:24:08 AM
Well, if 'reverse' means to make it the same as the GGG schematic, ok!  :)   Anode faces to the "right"...usually the longer leg of the LED...if it is reversed, it will simply not light up.
Title: Re: FuzzFace Late 60s GGG question
Post by: Atodovax on January 19, 2018, 09:59:01 AM
Isnt the anode facing left at the "Parts Layout" ?
Title: Re: FuzzFace Late 60s GGG question
Post by: bluebunny on January 19, 2018, 10:20:29 AM
No, it's the cathode facing left.  Here's a way to remember the orientation of the diode symbol: the triangle half of the symbol is like the letter "A" (anode), while the straight line into which the triangle points is like the letter "K" ("kathode").

(https://cdn.sparkfun.com/assets/learn_tutorials/7/5/backwardsDiode.png)