Tweak-o problem

[JJR]

Hello,

I have just tried to build the Tweak-o (http://www.smallbearelec.com/Projects/TweakO/TweakO.htm).
The problem :
My volume output is very low. I have to tune the volume on my amp all
the way to hear a soft distorted guitar. So i guess the effect works, my guitar is distorted and I can change the sound with the potmeters, but compared to the bypass sound, it is much too soft. :?
This cannot be correct, but I have checked the connections ect., and they all seem to be ok.

Any ideas ?
Thank you,

JJR.

[dansamp]

have you tried turning the transistor around?

i built one to but was not really impressed with the sound of it
there is just a few knob settings that get any usable sound
fuzz is about 1:00 o clock to about 3:00 o clock and the volume has to
be past 12:00 o clock
anyway as i said i am not impressed with it
but i think if the transistor is not installed properly it will produce the effect you are experiencing  :?

[JJR]

Thank you, but the transistor is installed correctly according to the schema, that's for sure...
Should I try turning it around?   :?
The effect I hear on the guitar is ok, as it is meant to be. But just too soft certainly in comparison with the sound bypassed.

I finally got my hands on a multi metre.

http://www.smallbearelec.com/Projects/TweakO/TweakO.htm
You can also use the low-voltage scale of your meter to sniff out problems. Hang the negative lead on point O-7. With both controls at mid-range, you should see roughly the following voltages on Q1: Collector 2.8 volts, Base 1.5 volts, Emitter .95 volts. If any of your readings are off these by more than 10%, you probably have a wiring error.

If I hang the neg. lead on the ground point, I always get a 0,00V  :shock:
If I hang the neg. lead on the neg. battery side I get these results :
Q1
C :8,77v
B :2,93v
E : 8,18v

Anybody got a clue ?
JJR.

[JJR]

After testing some more :
I always get a 0,0V with the neg. lug on the ground point. It does not matter where I hold the positive lug...

Am I doing something wrong ? This is all complete new to me  :roll:

JJR.

[JJR]

have you tried turning the transistor around?

I have just done this, did not help. If I turn the potmeters now, the sound stays the same. I'll try to mesure the V's tomorrow,

JJR.

[JJR]

*bump* :roll:

[JJR]

I picked this project up again, now I am wondering : could I have overheated the transistor ? How can I test this ?

Greetings,
JJR

[H.Manback]

You could try testing the transistor in your multimeter...

But what's more likely is that your grounding is wrong. Check if your ground point goes to the battery by testing each connection with the diode setting of your meter.

[kefestvog]

try putting twice as many diodes in the diode loop.  i did this with mine and it was night and day for both volume and distortion.

[darkseid]

I think H.Manback is right.  More likely is that your grounding is wrong....

The tweako was my first stompbox project and I had the same problems as you mention above, and it turned out I did not hook the grounds correctly.

the tweako does put out a good sound... I have recordings of it somewhere here

[darkseid]

Ah!  I remember I didn't hook up the voltage divider to ground, that would be C4...

But it maybe a totally different prob for you....

[Le Chat noir]

Hi, I'm new here, I registered because I too have completed a tweak-O and am having the exact same problem - when I plug it in, it has a true bypass but hit the switch, I get a very, very faint crackly signal, barely audible. I've checked and rechecked the soldering and the ground connections, below is a picture of the inside of the pedal, can anyone spot anything wrong? Or if the original poster got it sorted, do you remember what you did? Thanks in advance!

[Ge_Whiz]

Let's get this straight; when a guitar lead is plugged into the input (as per the instructions), the ground lug should be connected to the battery negative and readings with the DMM negative lead on either should give the same readings. If this is not the case, check the wiring around the input socket, to make sure that the power switching system is working. Also, plug in one half of the battery connector to the battery, and connect the DMM between the other power connector and battery lug, with the DMM set to something like 200 mA. Check the current draw when a plug is inserted in the input socket. Also, check that it is zero when the plug is removed. Let us know the results.

[Le Chat noir]

Hi, sorry, I'm really a beginner so I'm unfamiliar with multimiters etc, I'm just doing my best here! When I connect up one side of the battery and use the multimeter set to 200 between the other power connector and battery lug it reads 18.1 with the jack in, or 0 if the jack is removed.

I'm not exactly sure about if I'm doing this correctly to test the other reading, but if connect up just the negative battery terminal and I put the red lead of the DMM to the positive of the battery and hang the other end on the ground lug or the jack, I get a reading of 19.8.

Let me know if this is of any use to you, or if I'm donig something wrong please be gentle... as I say, i'm just an enthusiastic beginner who wants to learn

[Le Chat noir]

Oops! I had the multimeter set wrongly, sorry! Obviously 19.8 is silly, it's a 9V battery - I changed the setting, now it reads 9.4 as it should. So, when I connect up one side of the battery and use the multimeter between the other power connector and battery lug it reads around 9.4 with the jack in, or 0 if the jack is removed. So that eliminates that...

[petemoore]

C :8,77v
B :2,93v
E : 8,18v
  This emitter should be pulled to near ground [something less than...2v I guess] by the 2k2, the DC Emitter bias resistor.
  Remove power supply.
  Pick a ground point [one where it has to travel through connections...checks those connections too!], set the DMM to beep mode and test all grounds according to schematic, including the 2k2 lead, any other leads that are grounded, then set the DMM to R Range 20k, and test the resistance between ground and Q1E.