I am pretty new to building pedals and trying to learn more about circuits and schematics.
The Propolis Fuzz requires four 2N2222 transistors. I have four of the TO-18 metal can 2N2222 for the board and they all measured in the range of 70-80 hfe using a DCA55. They work fine and sound good, but don't have the extreme biting fuzz I was expecting from this board. I should be able to try any 2222, including plastic TO-92 P2N2222 or PN2222A, right? In fact, any NPN BJT might work in this circuit? Are there other specs I need to consider for a particular transistor to work well in this circuit?
Also, is there any need or benefit of "matching" the transistors in this circiut, like by hfe? My guess, looking at the schematic, is there is no need to "match" the hfe of the four. Swapping the transistors around might make slight differences due to different hfe ratings and pushing higher or lower gain into the next stage, but probably not noticeable. If it's true that "matching" transistors does nothing for this circuit, what is an example of a circuit where matching transistors is needed or desired for best results?
Thx!
Ken
The Propolis Fuzz requires four 2N2222 transistors. I have four of the TO-18 metal can 2N2222 for the board and they all measured in the range of 70-80 hfe using a DCA55. They work fine and sound good, but don't have the extreme biting fuzz I was expecting from this board. I should be able to try any 2222, including plastic TO-92 P2N2222 or PN2222A, right? In fact, any NPN BJT might work in this circuit? Are there other specs I need to consider for a particular transistor to work well in this circuit?
Also, is there any need or benefit of "matching" the transistors in this circiut, like by hfe? My guess, looking at the schematic, is there is no need to "match" the hfe of the four. Swapping the transistors around might make slight differences due to different hfe ratings and pushing higher or lower gain into the next stage, but probably not noticeable. If it's true that "matching" transistors does nothing for this circuit, what is an example of a circuit where matching transistors is needed or desired for best results?
Thx!
Ken