First perfboard build (fuzzface)working but..

[brujo]

Hi there, today was a rainy day so I decided to try my first build without kits. I used this layout http://effectslayouts.blogspot.com/2014/11/npn-fuzz-face.html
I just mounted components on pcb (no bypass switch) and surprise it work.
Q1-2 are bc547c (one has no b )
D1 is a 4007
2,2M is 1/2 watts

both pots are linear and the volume one is 470k instead of 500k. Honestly it does not sounds bad,it has pretty much hum (maybe because all the ground are togheter? I mean jack in and jack out to ground) and the volume it does not affects as a volume but more like  a tone  (close the sound at 9 and open going thru 3 o'clock).what can yo tell me ?
thank you to everyone. I really enjoy make this thing. cheers

[knutolai]

Some things to note:

* Schematic asks for a logarithmic pot for the volume. This will give you a more linear volume increase across the pot travel.
* 470K instead of 500K makes no difference.
* Generally you will hear more hum from circuits on a breadboard/exposed PCB than one placed in a shielded enclosure (e.g. an aluminum box). Try shielding the circuit and see if that makes it better.

[r080]

the volume it does not affects as a volume but more like  a tone  (close the sound at 9 and open going thru 3 o'clock).

Are you getting any change in volume? Does it turn the effect completely off at one end of the rotation?

[Electric Warrior]

Some things to note:

* Schematic asks for a logarithmic pot for the volume. This will give you a more linear volume increase across the pot travel.
* 470K instead of 500K makes no difference.
* Generally you will hear more hum from circuits on a breadboard/exposed PCB than one placed in a shielded enclosure (e.g. an aluminum box). Try shielding the circuit and see if that makes it better.

Actually 470k lin is the stock value for a silicon Fuzz Face.

[brujo]

No changes in volume,and no it doesn't turn the effect off at the end of rotation

[percyhornickel]

I have a breadboard with a siicone FF mounted on it, sounds great just biasing the collectors on both transistors:

Vcc = 9.0 V

Q1c = 0.45 V

Q2c = 4.5 V

Put a couple of trimmers (50k) to set bias and yes, the hum is there because is not inside a metalic case.

I tried other voltages just to test but really liked the recomended ones.

Last week I welded on a pcb my germanium FF with trimmers too, and again...  ..loved the recomended voltages sound.

Q1c = 1.35 V

Q2c = 4.5 V

I´m thinking letting a external pot for Q2c bias...         

Both transistors are leaky ones but the sound I´ve got is amazing after biasing and no weird noise and no hiss.

Saludos 

[brujo]

Thank you,so the volume issue remain a mystery,I thing I'll try to do more FF and see what happen. Thanks for the trimmers suggesion. Where they should go?collector,base,or emitter?

[percyhornickel]

Thank you,so the volume issue remain a mystery,I thing I'll try to do more FF and see what happen. Thanks for the trimmers suggesion. Where they should go?collector,base,or emitter?

The 50k trimmers are used instead 33k and 8.2k .
Just used the legs 1 and 2 (you can weld 2 and 3 if you want.

Just adjust voltages and let us know your results.

Try to upload a better picture to see your vol pot conections...   

lug 1..   ..10n     (check this one)
lug 2..   ..output
lug3..    ..ground

[brujo]

thanks again,connections seems right.... :icon_exclaim:I know soldering here looks like a  battle..eheh I need a smaller tip and some excercise I hope...
sorry but it does not let me put images in right now

[brujo]

boxed

[duck_arse]

boxed

I don't quite know what I'm looking at here, but I like it.

[percyhornickel]

boxed

I don't quite know what I'm looking at here, but I like it.

Sputnik Face? / Orbiter Face?...

[r080]

Bier Gesicht?

[brujo]

Hi, I am trying to bias transistors but I cannot ready any noticeable changes in collectors voltages. Lug number 2(the one that is alone,right?) goes to Q's collector,and 1 or 3 (One of the two sided toghether) Is placed between 10nF cap and 330ohm resistor. What is not working here?!?

[antonis]

Check your particular trimpot for correct lug orientation..
e.g. resistance between lugs 1 & 3  should stay stable, despite lug 2 (wiper) various settings..

P.S.1
I'm talking for lug 3 "open" configuration..



P.S.2
Forget all above and desolder, clear and solder timpot again..

[Phend]

Cool Hershey Kiss chocolate example of packaging.

[brujo]

the area you evidence is connection between E,100k resistor and fuzz3,but yeah need deselder probably,anyway I tried connecting the other lug of trimpot (also replace trimpot because one of the lug broken) and now it is "biasing" so thank you. On the other had it does not sound at all right now,so  probably there are a little bit too much messy solder here and there . Anyway thank you for the advices.
cheers

[brujo]

I checked again and looks like trimpot do not  works and I read a negative voltage on Q1 base trim is on q2

[brujo]

Hi,I rebuild it again,following the same schematic http://effectslayouts.blogspot.com/2014/11/npn-fuzz-face.html. I guess I managedthe biasing thing but I can't get any sound,seems like input is dead. I followed the schematic just use 2 4,2M resistor between input and ground (very close value of 2,2M of schematic). Following reverse path of signal I can ear noise from output jack,then trou the swithes and volume,but when I arrive at the 10nF cap , I can get signal only from one side (the one connected with voume pot) but the cap is good.
9v at D1 =7,75
Q1: e=0,90V;b=0,48V;c=1,10V
Q2: e=0,45V;b=1,15V;c=0.45V bias pot is a 50k trim setted at minimun voltage gain on Q2 emitter (max clockwise).
Any clues on what I'm doing wrong?