Built my own fuzzface (general guitar gadgets kit) and it doesnt work correctly?

[bboy_jon]

Maybe its just me, but it doesnt sound very fuzzy?

i bought this kit

http://www.generalguitargadgets.com/index.php?page=shop.product_details&flypage=shop.flypage&product_id=130&category_id=7&manufacturer_id=0&option=com_virtuemart&Itemid=45

i just tried it in comparision to my overdrive (boss sd-1) and distortion (Danelectro fab distortion) and it basically just sounds like my overdrive...

Ive messed with the one taper pot and (turning clockwise, lets go from a scale of 1 to from 1 to 4 it sounds like overdrive, then around 4 its about as fuzzy as it gets (still pretty much sounds like overdrive) around 5 it gets fuzzier but the volume also drops significantly and then past that it doesnt let any sound through...

[frankclarke]

PNP or NPN?

[8mileshigh]

Get out your DMM and let us know what the voltages are on both transistors.  It should sound like a ripping fuzz.

Chris

[Dragonfly]

You have a problem with your build.


Read the "What to do if it doesn't work" thread stickied at the top of this forum, take your measurements, and post them here so we can help you debug your build.

[bboy_jon]

it is the NPN version. According to the instructions the voltages for the transistors should be

Q1

C 1.4v
B 0.6
E 0.0

Q2

C 4.5 (adjustable with trimmer pot)
B 1.4
E 0.8

I get

Q1

C 0.0v
B 0.63
E 1.78

Q2

C 0.94 - 1.09
B 1.63
E 0.98

They are pretty off :/

I dont know if it would be the same with all the optional stuff they say you can use. I used

R5T (the trimmer pot)
R1 (the resistor to stop the "pop effect")
C4 (10 pF cap to reduce interference)
D3 (diode for reverse voltage protection)

Using D3 says it will reduce voltage by about 1 volt.

[Dragonfly]

have you checked to make sure the transistors are oriented properly ?

[bboy_jon]

according to the picture yes.

[R.G.]

The bottom line is this:
- the circuit and board is known to work well when it's assembled properly
- therefore, there is at least one, if not more differences between your version and a properly assembled version
- the 0.0V on the collector of Q1 and the fact that the base of Q2 - which is connected to the collector of Q1 by copper trace - are not the same voltage means there is at least one flaw right there.

When you get the differences ironed out, it will work properly. Hundreds if not thousands of others of that have done so.

[Dragonfly]

In addition to what RG said....

if Q1 has voltage present at the emitter, than you have a ground problem. If your grounds were properly connected it would show 0 volts, as it is directly connected to ground.

what transistors are you using ?

Q1 is way off on the voltages... collector should be around 1.5v but youre showing 0 volts...it almost seems like you built the "PNP version", but used "NPN transistors"

[bboy_jon]

the npn transistors are  CENPN 2369A. I plugged in the pnp transistors that the kit came with and i got nothing. by pass works but as soon as i hit the switch no sound gets through

[tiges_ tendres]

the npn transistors are  CENPN 2369A. I plugged in the pnp transistors that the kit came with and i got nothing. by pass works but as soon as i hit the switch no sound gets through

You cant simply change PNP for NPN transistors.  Do you have the red battery lead or black battery lead going to 9v on the board?

[Dragonfly]

the npn transistors are  CENPN 2369A. I plugged in the pnp transistors that the kit came with and i got nothing. by pass works but as soon as i hit the switch no sound gets through

...it almost seems like you built the "PNP version", but used "NPN transistors"

Or vice versa...

[bboy_jon]

red

[Dragonfly]

red

Then I assume you followed THIS layout ?

http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_npn.pdf

[bboy_jon]

yes

I think i am confusing my self a little. On the transistors, i know what the collector, base and emitters are on a schematic diagram but on the actual transistor, say you have the flat side facing you, is the emitter the left or right lead? ive found a few diagrams and they have the emitter on either the right or left....

[Dragonfly]

A quick look at the datasheet will answer your question...

http://www.fairchildsemi.com/ds/PN/PN2369A.pdf

[bboy_jon]

ok that solved my confusion. Well i traced everything, everything seems like it is attached to where it should be

[Dragonfly]

ok that solved my confusion. Well i traced everything, everything seems like it is attached to where it should be

To quote RG....

Mother Nature does not lie, but she is a stickler for details. If it was put together perfectly, it would work. It not working is Mother Nature's way of telling you that you made some tiny error, and it's no reflection on you if it's not perfect the first time.

It's a known, working schematic and layout...therefore, regardless of how many times your eyes tell you that it's correct, Mother nature doesn't lie...you have a mistake. It could be a small one, could be a large one.

You might look into building an audio probe. A quick search of the forum will tell you how...it's simple.

BTW...this has happened to ALL of us. We've ALL been convinced that a circuit was built perfectly, only to find out after tearing our hair out that we made a mistake.

[Dragonfly]

BTW...if you can post detailed photos, that may help as well.

[bboy_jon]

ok well i made an audio probe but i dont really know where to start. I hooked the ground up and i checked the transistor leads.

Q1

E Gives me nothing
B can hear my guitar
C can hear my guitar

Q2

E can hear my guitar
B can hear my guitar
C makes a big pop and very loud noise

where else should i check?