BMP tonestack

[brujo]

Hi there, I have build this tonestack http://tagboardeffects.blogspot.com/2013/08/bmp-tonestack-w-lpb1.html using 33k(both ) resistors on tonestack and as capacitor a 10nF(as schematic) and a 22nF(instead of 4,7nF) and added at the end of a bc109c FF circuit (250k volume pot). I put a 330 ohm resistance instead of a 390 ohm one(BMP tonestack low right on the schematic). Rotating tonepot all counterclockwise completely cut off all the sound from the circuit,as you open , it start sounding,unleashing true tones and gain only in the second half of the rotation( very harsh tones). it's like it does not work as a tone properly, what I am not getting?



cheers

[antonis]

Could you post a draft schematic/diagram instead of making us guessing or tracing layout..?? 

[brujo]

How can I do what you are asking me?

[antonis]

Never mind...

Let it be..

[brujo]

 
Anyway It Is a npn FF ,it's volume output go trough the in of the tonestack. This Is the layout of the fuzzface..https://www.google.com/search?q=sunface+veroboard&oq=sunface+veroboard&aqs=chrome..69i57j33i160.5025j0j7&client=ms-android-oppo-rev1&sourceid=chrome-mobile&ie=UTF-8#imgrc=Lpv5G8ADWOVOZM reversed alimentation and caos polarity.

[antonis]

I'm not aware of any single BJT Fuzz Faxe circuit..

Could you plz verify if the layout below is the one used and modified..??

[brujo]

Yes it's this one,as the same on the First post link

[iainpunk]

we'd like to see a picture of the solder side of the board, and the DC voltage readings of the transistor pins.
i suspect a bad solder joint

cheers

[Bunkey]

Alimentation & Chaos is a freaking awesome A/B side EP title btw.

I'm calling it.

[brujo]

Ahaha caps ( damn autocorrector). Thanks for the help,I Will give you a photo as soon as I can. Anyway I think I Will try Also a 1uF cap for the bass section,let's lee

[Bunkey]

Theres a really useful program here which graphs the frequency response of various tone stacks, including the BMP, using whatever components values you want to input:

http://www.duncanamps.com/tsc/

[antonis]

I Will try Also a 1uF cap for the bass section..

33k & 1μF for LPF set cut-off frequency at 4.8Hz..!! 

You better make Bass cap 10nF or so and Treble cap 4.7nF..

[marcelomd]

Theres a really useful program here which graphs the frequency response of various tone stacks, including the BMP, using whatever components values you want to input:

http://www.duncanamps.com/tsc/

Check this: https://www.guitarscience.net/tsc/info.htm

Made by fellow our forum fellows. Web based. More tonestacks.

[Elektrojänis]

If there is no sound on one end of the pot's rotation and the sound is harsh on the other end, there is probably an error in connections on the bass side filter (39k and 10nF on the original) or the pot is wired wrong.

Did you notice that the pot connections are NOT in straight order in teh layout... the middle pin of the pot goes to the lowest connection on the stripboard layout.

If the pot is connected correctly, look for bad solder joint or short around those two bass side filter components.

[brujo]

[antonis]

Hmmmm... 

[iainpunk]

Hmmmm... 

[img height = 100]https://i.imgur.com/10HMhtJ.jpg[/img]

i strongly agree, but i might be prejudiced by the prediction i made earlier.

i also agree with the suggestion that the bass side of the tone stack might be the culprit.
i'd like to see a picture of the off board wiring of the potentiometer as well, that'd be great

cheers

[antonis]

Rotating tonepot all counterclockwise completely cut off all the sound from the circuit,as you open , it start sounding,unleashing true tones and gain only in the second half of the rotation( very harsh tones)

It strongly calls for Bass shorted cap (10nF on layout)..

[brujo]

I did some trials with bass caps values and I always got full cut on all counterclock pot position. That spot looks soldered but It Is not. I will give you pot wiring as I can , and I Will try to checks solder joints again.
Thanks you all.

[antonis]

I did some trials with bass caps values and I always got full cut on all counterclock pot position.

Try it without any Bass cap..
(of course, you'll not have Bass responce but we want to find out if full cut is due to some shorting to GND..)

Just make sure that there isn't any kind of short between cap legs pads..