- This topic has 6 replies, 2 voices, and was last updated 5 years, 4 months ago by
.
-
Posts
-
As the topic says I have just built my first pedal a Photon Phuzz. I have tried to build using vero but not successfully so I am grateful that you make excellent PCB’s it saved a lot of grief, I can learn how to make pedals without having to reinvent the wheel.
This was a stock standard by the diagram build
I will defiantly be building more pedals
Three things immediately have become apparent, 1. There is a very narrow band of usable noise that comes out of the thing. 2. the sound dies off very quickly from when the note is plucked hardly any sustain at all. 3. When I adjust the volume the tone changes quite dramatically
What can I swap around to try and address these issues? I could randomly swap components but a bit of guidance would be appreciated would better quality or type of capacitors help the sustain issue? do I swap potentiometers for bigger or smaller values? I intend to try a different Transistor, do the diodes affect the sound?
Tim it sounds like a pot issue I can’t see all of your values from your photo and obviously can’t check the capacitors, R1 and R4 values cannot be clearly seen
Are your pots both B10K? it’ll either have B10K or a code of B103
If you haven’t already check all values also post a picture of the solder side of the pcb
Have Re-rechecked all values seem to be correct
The parts look correct from what I can see Tim
Reflow all your solder joints hold your iron on the joints for around 4 seconds until the solder flows
The joints on the bias pot look ball like and could be dry inside, this would affect your transistor biasing as you turn the bias pot the voltage to the transistor collector pin should change ( the outer pin without the small metal tag)
With this being a small circuit I’d reflow all joints
Well i reflowed the solder joints and succeeded in making the thing go from working to not working. I have gone beserk with the multimeter and found all resistances are fine and continuity is right I suspect the transistor is dodgey as it would not work in the sockets in the beginning until I soldered it in place. I have ordered another one and when I have installed it i will update this post
You can check your transistor internal diodes with your meter Tim to see if it’s good or not
https://www.allaboutcircuits.com/textbook/semiconductors/chpt-4/meter-check-transistor-bjt/
Transistors can be damaged by heat from your iron you really only want to solder for 3 to 4 seconds you actually did the correct thing initially using a socket if you have another socket I’d recommend using that obviously be careful you don’t accidentally lift a solder pad again with you removing the socket your pads have been subjected to a bit of heat
When using sockets don’t solder the transistor pins in until you’re happy it all works I usually only solder 1 in to hold the transistor in place if you have a small croc clip use that as a heatsink by clipping it on up near the transistor body
OK I worked out my problem it was a very silly mistake I had somehow along the way accidentally swapped the tip wires from the socket tips to the foot-switch around.
I now have anew problem that is that the Bias is not working. Turning the pot from one end to the other makes no difference, the voltage going into the transistor remains constant at 6.1 all the components are correct values and working,
- You must be logged in to reply to this topic.