colorsound tremolo dragonfly layout

[NekoNeko]

Hi

I am quite new to building stompboxes although i have built a few before, but simple ones. I have built the colorsound vero layout by dragonfly but guess what it does not work. When its powered up and stomped on it just reduces the volume of my guitars signal to near unaudilble. I can hear a slight tremelo effect but extremely subtle and the pots don't change anything. I have checked my wiring and component values and i cannot see any mistakes. I think it is a wiring problem but i am not sure.
Any suggestions?

thanks

Gray

[snoof]

if you post the voltages from your transistors, someone may be able to help you further...

[96ecss]

Hi, just follow the instructions here and someone will be able to help you. http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Dave

[NekoNeko]

OK thanks guys. I will post the readings. First of all i have read all the debugging pages that exsist but i am still scratching my head. When it says put the black lead on ground and the red on whatever, i confused to exactly which ground. is it the black battery lead, the ground rail on the board or the ground on the jack sockets? I have tried these and cannot get any results. Second of all when testing the values do you use the bottom (copper side) of the stripboard or the top? Thirdly should i have the battery connected when performing these tests? I am sorry for the very basic questions i have searched the forums and can't find any info.

[MikeH]

Yes you need the battery connected.  And you need to have a plug in the input jack.  And then it should work.  You can touch the black lead to any ground to measure voltages, because all of the grounds are connected.  I usually just aligator clip it to one of the ground lugs on the jacks.  And when you probe with the red lead you can either do it on the bottom side, or just touch any exposed component leads on the top (which I find is easier because you can see what you're probing, and often times you end up measuring IC's and Transistors backwards from the bottom).  Post you results using the checklist in the "Debugging- what to do when it doesn't work" thread.

[NekoNeko]

thanks very much MikeH. Thats cleared everything up for me. I can't wait to measure the voltages and get this baby one step closer to working.

[NekoNeko]

Right here are the results

1. Colorsound tremolo

2. Layout url - http://www.aronnelson.com/gallery/v/DRAGONFLY-LAYOUTS_0/album19/album145/COLORSOUND_TREMOLO_VERO_001.gif.html

3. On stripboard

4. No mods or substitutions

5. Negitive ground

6. Signal passes through the circuit the same when bypassed. there is no effect ie no tremolo but the guitar signal is present. Pots make no effect to the sound.

7. 9.56 battery reads out of circuit

Q1
C =2.68
B =2.19
E =1.77

Q2
C=0.00
B=0.00
E=0.00

Q3
C=5.66
B=0.60
E=0.00

D1
A =0.00
K =9.56

[NekoNeko]

Please can some one help me?

[dxm1]

I can't find the schematic or layout you linked to, but it's obvious that you have a problem around Q2. Check the components in that area...

[NekoNeko]

heres the schematics



and the layout



I've checked all the component values and there correct.

[MikeH]

Check your orientation of Q2- note that it is opposite of Q1 and Q3

[NekoNeko]

Checked it it's the right orientation. this circuit is driving me mad. any more ideas?

[rackham]

You've probably already done this, but what fixed mine was...

Take your DMM and go over the base of the board to make sure you've not got any slivers of copper forming a bridge from where you cut the tracks - look for connections where there shouldn't be any.

[NekoNeko]

aha. sucess. Now i am getting the signal through the pedal (no effect though) but it fizzles out in a kind of crackling noise. A bit like the worst fuzz you've ever heard. Pots still don't work. I double checked my traces and replaced Q2, triple checked wiring and components. At least now i feel like i am getting closer to getting this to work and learning about debugging aswell. Thanks for the help everyone. Anymore ideas?

[NekoNeko]

I am getting close i can smell it!! I poked around with an audio probe and couldn't find any problems. I was using music from my laptop as an input signal with the audio probe via the headphone out and the effect worked great. so i disconected the audio probe and plugged my guitar in and the signal comes through then fizzles out into nothing. tried it again with laptop line out and it works great. I tried turning up the laptop to see if i could replicate the same problem with my guitar but i couldn't. This leads me to think the guitar is overloading the circuit, but i don't understand how? The laptop out is stereo but the guitar is mono output. would this cause this problem?

[NekoNeko]

Please can someone help me?
I hate to bump threads but i need to finish this for my sanity! i cannot find any info on the forum.

[MikeH]

Are you saying that when you use a signal from your laptop, the signal passes all the way through the effect and the controls work?  If that's the case I have no idea why a guitar signal wouldn't work.  The point is to trace the signal path until you find a break, or signal loss, or signal someplace it shouldn't be, and then you've found your problem.  Try a continuity meter.  Make sure there aren't any traces that are connected that shouldn't be, and make sure those that should be are.

[hellwood]

5. Negitive ground
Q1
C =2.68
B =2.19
E =1.77

Q2
C=0.00
B=0.00
E=0.00

Q3
C=5.66
B=0.60
E=0.00

D1
A =0.00
K =9.56

your measurements dont make sense. Q2's emitter and Q3's base should have the same measurement. there is no mention of Q4. i think you need to check again and repost your measurements. the schematic you posted is pretty blurry but it looks like Q2's collector and Q3's collector should have the same voltage as well.

[snoof]

the layout is different than the schem.  it doesn't use the darlinton arrangement.  This is most likely the schem used...

http://www.aronnelson.com/gallery/v/TheBigMan-Layouts/col_trem.gif.html

Edit: Oops, scratch that, it uses a mspa13 darlington, as opposed to using two trannys in a darlington arangement.  but the above link is another valid version of the schem.  Q2 on the layout = Q4 on the schem, and Q2 & 3 are combined into Q3 on the layout which is the mpsa13.

[hellwood]

I was using music from my laptop as an input signal with the audio probe via the headphone out and the effect worked great. so i disconected the audio probe and plugged my guitar in and the signal comes through then fizzles out into nothing.

first of all, an output signal from your laptop is WAY more intense than a guitar signal. if anything, this could be a clue that your bias is the problem. it could but probably wont kill your laptop's amp to run stereo into a mono jack. it would be better to get an adapter so you can split the stereo into mono's and use the mono L or R.