Colorsound Overdriver debug

[Electric Warrior]

The factory schematic is the historical bug here. 

[Georgedepinedo]

Oh my God. Thank you all for participating but what was wrong was the stupidest thing that could be wrong. It was the layout. A bunch of people used that layout to make the CS Overdriver so I figured why should I put the layout / schematics relation to the test. But in the end I did just that, and one electro was turned wrong, I fixed that on my vero and everything worked beautifully.

I subbed the bc184b for the bc109c trannies and I think I like the sound better. These are a little higher hfe, 430 all three. I got more sustain and the grit is equally beautiful through the whole Gain pot rotation. I am very pleased with the effect so far.

I can't believe it was all wrong because of the layout. What a bummer. Thank you all for scratching your heads for me, a virtual beer to everybody!

Hello there, I know it has been a looooong time, but may I ask which cap was reversed? Thanks a lot.
Nevermind, this has been adressed already. Me and my assholish custom of not reading first.........

[Georgedepinedo]

Hello there, I know that this post is old as hell, but would you mind sharing which cap was reversed?
Thanks !!

You should post a link to the layout and schematic you are using.

When I look at the layout and the photo of the build in this thread I cannot see a cap backwards!

For that circuit (as far as I know), the cap polarities can be summarized as:
- if a cap connects to an emitter the cap+ goes to the emitter.
- if a cap connects to a collector the cap+ goes to the collector.

There was a thread back in 2013(?) discussing some points about this circuit.

Thanks for the reply, I am using the same layout that is linked at the beginning of the post. It exactly the same that I have from another site.

[Georgedepinedo]

OK I think I have solve the mystery of the Colorsound Overdrive Colorsound Powerboost.
With the aim of trying to put this issue to bed once and for all I traced the Power boost pcb.

The summary is:
Fix 1) The cap's going to Q3's collector should have their +terminals going to the collector.
          In particular the cap from Q3's collector and the tone control which is shown the wrong way around
          on some schematics.
Fix 2) The 12k resistor connects to the emitter of Q1 and the collector of Q2, not the other side of the cap
          as shown in the original schematic.

The wrongs of the past:
- What's happened in the past is the 12k resistor connected to the wrong side of the cap on Q2's collector.
  This is how it is shown on the original schematic.  This removes any DC from the 12k resistor and upsets
  the DC biasing of Q1.
- The "wrong" fix was to reverse the electrolytic cap between the collector of Q3 and the tone control.
  Reversing the cap to the wrong way around causes it to leak DC through the 12k resistor.  This
  pushes the DC closer to what it should be so people think this is the fix.

In this old thread Electric Warrior posted schematics showing  the correct connections:
https://www.diystompboxes.com/smfforum/index.php?topic=103268.0

The problem now is there's dodgy layouts out there which need to be fixed:
1) The electrolytic cap which connects between Q3's collector and the tone controls should have its
    +terminal connecting to Q3's collector.
2) The 12k resistor which goes to the electrolytic on Q2's collector should connect to Q2's collector.


EDIT:
FYI for those who want to see the PCB.

Man, I greatly appreciate this.

[Paul Marossy]

I don't have anything to add really except that I made one almost a year ago and was doing prototyping at 4AM with an aluminum pie tin. 
(my day normally starts at 4AM, so that's why so early in the morning)

I was just using it this morning. I mostly use it for clean stuff with delay where I want it the sound to be a little brighter with my DIY Marshall speaker cab simulator. I have different knobs on it now, they look a little closer to the originals.

[Georgedepinedo]

Man, I built one in the past and it worked charms. This one has been giving me headaches for the longest. I am not an electronics theorist, I just follow schematics and most of the time they work as they are supposed to, but I suck at troubleshooting. Thanks so much for all the info you guys have shared on this post. Whenever I fix mine I'll let you know what was wrong.

[Paul Marossy]

Man, I built one in the past and it worked charms. This one has been giving me headaches for the longest. I am not an electronics theorist, I just follow schematics and most of the time they work as they are supposed to, but I suck at troubleshooting. Thanks so much for all the info you guys have shared on this post. Whenever I fix mine I'll let you know what was wrong.

Sometimes I don't find my mistake(s) until it has sat for a week or two. Then I come back to it and it slaps me loudly in the face.