Weener Wah 2016 Problems

[spoontex]

Hi,

I've just build the Wenner Wah 2016, and I have some issues. When the effect is on the Wah is very subtle and I have a volumen drop. I revised the circuit many times and I have no idea... You can help me?

I've used BC239B instead BC109



http://es.tinypic.com/r/11vgmm1/9

Thanks.

[midwayfair]

Please post voltages, audio probe results, and any other information identified in the tech help rules page:

http://www.madbeanpedals.com/forum/index.php?topic=902.0

[Ralfg]

Yeah we need more info.  Wild guess, have you checked the pin out of your transistors?

[spoontex]

Sorry, these are the readings:

Q1

E= 7.82V
B= 0.581V
C= 0.03V

Q2

E= 9.79V
B= 1.76V
C= 1.21V

D1

+= 10.07V
-= 9.90V

Is normal that the collector of Q1 dosen't have any voltage?

[midwayfair]

Is normal that the collector of Q1 dosen't have any voltage?

That's the emitter, not the collector. Double check the datasheet if you aren't sure which pin is which. Actually, check the datasheet even if you're sure which is which. Always check the datasheet.

The Q2 base and Q1 collector are DC-coupled, albeit across a 470K resistor. Q1 looks mostly okay except that Q1's collector is high. It should be closer to 4.5V. Q2's base should end up very close to that around 4V.

[spoontex]

Oh!!!! Yes!! I put wrong the transistors... sorry... I always check the datasheet... a big mistake!!

Sorry and thanks!!

[spoontex]

Okey,

I've change the transistors with some BC109B with 220 to 260 hfe. And I raise R7 to 68k. But the wah sounds strange... It's hard to explain. I upload an audio file.

https://soundcloud.com/david-rotger-573523264/weener

thanks.

[madbean]

That actually sounds like backward transistors to me. Are you sure you oriented those those BC109 correctly? The tab is the emitter (should be on the right side looking down on the PCB).

All you caps and resistors look correct. So, it would seem to be transistor-related or the inductor.

[spoontex]

The transistors are oriented correctly, and the inductor is new from Mark Foley:

http://mfguitarproducts.simpl.com/online_shop.html

Now I've adujusted the pot, and now sounds better... but not all.

https://soundcloud.com/david-rotger-573523264/weener2

What do you think??

[spoontex]

Anyway, I have a Dunlop Red Fasel. If you want I can tray to change...

[Ralfg]

I don't think it sounds all that bad now. I built the Werner wah a while back and I ran into some problems, I found it to have too much gain so when I was wahing it would distort heavily when I pulled back on the wah. I ended up trying a few different transistors to see what it did and ended up using some much lower gain transistors, which reduced the distortion significantly. I also added a switch to r4. I found that clean I wanted the gain to be lower but when I was driving a distortion I liked the higher gain and was ok with the wah distorting a bit. I also added a switch or r7, I think I used an on-on-on switch with 3 different values. I found that the way r7 changed the Q it seemed to have an effect on how the wah would clip. I did the switch so I could pick which one I wanted based on what I was going for.

I also felt that the wah was pretty hot, which depending on the amp I played, specifically low wattage amps would also cause the sound to clip. So I added an output buffer with a level control at the end. I used the FoxRot buffer I found on tagboard effects. In the end this wah turned out really good with tons of versatility.

What are you trying to achieve as far as tone?

[spoontex]

I built the foxrox buffer into the wah. What kind of transistors do you mount? I want a clean wah and very vocal. It's probably that the bc109b have a lot of gain. These ones that I install have 220 to 260 hfe.

[Ralfg]

I used 546b I think.  You might be able to get a cleaner sound by increasing r4 and maybe even trying to increase r2?  I assume by reducing the signal to q1 you would get less gain.  Also might be worth reducing r7 to get flatten out the q.  For me messing with r4 and r7 really let me dial it in to a point where I really liked it.  I did not mess with r2.

[spoontex]

Ok, thanks. I try the bc546. What do you think about bc173??

[Ralfg]

Don't know, give em a try.