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SOLVED Simulcast quiet/thin sound


Defo worthwhile getting into the habit of using an audio probe it's something I wished I'd done sooner

A lot of the time it cuts debugging down from hours to minutes

Whilst you're waiting why not have a go at tracing the audio path out on the schematic using the audio probe PDF, the basic audio path for this one's pretty straight forward
Will do. I think I have all the parts how critical/or required is the .1uf capacitor? Can other values be used or is that the magic value?


This one's not too difficult to trace as it says in the Audio Probe Explained PDF I linked on my google drive

Tracing the audio path is very much like "join the dots" in that you have to get from the input jack to the input of
the first active component, from the output of the first active component to the input of the second active
component and so on until you reach the output jack.

Anyway to get you started:

You'd start at the IN pad to the first component C1 through both sides of C1 to the input of the first active device Q1s base then out through Q1 collector to Q2 base and so on till you get to the out pad just trace a basic audio path from the IN pad through the components in line between that and the first active device out of that through components to the 2nd active device until you get to the OUT pad

You'll notice differences in sound etc, eg when it goes through an RC filter the frequency will change it'll get louder through an amplification stage and so on

You will find where you lose your volume it'll defo be noticable

Chuck D. Bones

Well-known member
We all end up troubleshooting our stuff from time to time, it's part of pedal building.
Lesson #1:
Always check your work. I've been building pedals since... well let's just say that Keith Moon was still alive. I always check my work and I'm still finding the occasional bad solder joint, part in backwards, etc.
Visual inspection is your most efficient troubleshooting tool and it requires no training or electronics expertise. You need good light, good eyes, magnification and attention to detail. Look at solder joints, part values, orientation and external wiring. You can fully inspect one of these boards in under an hour.
We're happy to help with troubleshooting, but do us the courtesy of inspecting your work before asking for help. I think you'll be pleasantly surprised how many times you're able to fix a board on your own.

Chuck D. Bones

Well-known member
Not at all. It's just a friendly reminder that before you break out the DVM and audio probe, do the inspection. As a matter of fact, the best time to do the inspection is during the soldering process. As parts get added, parts of the board become less accessible for inspection and rework. You're really better off finding problems as early as possible. It's a real pain having to remove a pot to gain access to the pads underneath.

After one spends a little time reading this troubleshooting forum, it becomes clear that the top two causes of a pedal not working are: bad solder joint & wrong resistor value. It's pretty easy for us to spot a wrong resistor value in a photo (a good photo anyway), but solder joints need to be inspected at various angles. Only the guy holding the board can do that.


Totally agree

But must admit sometimes in my eagerness to get it sparked up I don't always do what I know I should like checking resistors with my meter

I guess I'm a bit of a bad boy after all!