Some help/advice please

[Beerrhino]

I've built pedals from kits (BYOC) and I just decided to try and take schematics and build a fuzz based solely on that.  I picked an easy one to start: http://www.seymourduncan.com/tonefiend/wp-content/uploads/DIY-Club-Project-2-v02.pdf
I have it breadboarded and it works...sorta.  When I switch the fuzz on it almost sounds like it has a gate on it.  I need to hit the strings pretty hard to get a fuzz tone out of it.  The fuzz effect will fade out while the clean guitar signal remains.  If I'm just playing single note lines I don't get any fuzz unless I'm really smacking the strings.  I've compared my breadboard to the schematic a hundred times, everything is wired correctly, and I've tried several different types of transistors...same result.  I've also tried several different batteries with identical results.  Any help is appreciated.

[EBK]

Could you post a pic or two of your breadboard?

[Beerrhino]

[EBK]

Is that gray cap connected at both ends?  It looks like one end is floating.....

[Digital Larry]

Joe Gore, who came up with that circuit for SD, now has his own blog.  You might consider asking him at www.tonefiend.com.

[granite]

I love this circuit, it was my first build as well!

The output cap is connected to the same row as the diode? To me it also looks like that it is on the wrong line.

I just quickly breadboarded one and it clips like there is no tomorrow.




If it is not the cap, I would recommend moving the transistor to one side of that IC channel. I have seen them not making good contact with all the leads when they are spread out like that.

What voltage are you getting on the transistor pins?

Mine - with the input grounded - are - battery is 9.4V :

C: 0.79V
B: 0.57V
E: 0 V (duh)

[Beerrhino]

the gray cap is connected on one side to the 100k resistor, diode  and collector.  on the other side to the effect out

[granite]

Ok, must be the angle why it looked like that that cap was floating.

This may just be the picture angle again but is the emitter grounded? Can't tell where that red cable ends.

[Beerrhino]

The emitter is grounded.
battery voltage is 8.93
C: .13
B: .12
E: 0

[EBK]

Are you measuring that supply voltage at the supply or at the 100k lead?

[EBK]

And, what specific transistor are you using?

[Beerrhino]

power supply.  at the 100k its .12

[Beerrhino]

I used several transistors, all with the same results. 2n3904, 2n5088, 2222a, bc108

[granite]

Aren't these voltages really low?

I thought that a normal NPN transistor should have diode-like forward voltage between Base and Emitter. That would mean 0.5 - 0.7 V?

Considering you swapped transistors, can that diode be broken?

[EBK]

The voltage on the power supply side of the 100k, but measuring at the resistor.....  is 0.13 or 8.93?

[thermionix]

I just chunked one on the BB, got pretty much the exact same voltages as granite.  2N5088 and 1N914.  Tons of fuzz.  Had to reduce the input cap to 10n to sound decent.  It does get gatey when the input is really low, makes a sort of click when the pick first touches the string, and gates out after note decay.  I'm not a fan of that personally, but some folks dig it I know.  Pretty cool for $0.25 worth of parts though.