Good circuit for testing out NPN / PNP transistors? (Newbie)

[Steben]

Reversing emitter and collector is known to give transistor action but at a lower hfe.  But I agree that C2 should be reversed.

+1 agree..

But in the above (decaffeine!!) schematic, BJT works as a poorly biased Emitter follower..

EHX solders some Muff Overdrives like this

[I_Am_Jon]

My little test setup seems to be working ok:


Waiting for bipolar 47uf cap before I solder, so board can run with PNP or NPN if I reverse power supply.

Then I can get back to my bass muff project At least i've learnt some stuff about working with PNP's now.

[I_Am_Jon]

Finished my little project. Tested a mix of NPN, PNP, Silicon and germanium with it, gives a significant signal boost with enough control to go from clean to some distortion on higher gain transistors. I'm using 100nf filter caps but runs as Rangemaster Treble boost if swap caps to original smaller values.

Have added input gain control on the emitter cap. Slightly too deep to mount direct in a 1590b @ 70mm  x 30mm but this is meant as a desktop test rig rather than finished pedal.






Not decided on my next project yet, might try a veroboard based design.

Want to have a go at making a finished pedal in case. Anyone tried laser engraving a Die Cast Aluminium Enclosure? I have access a 3D Fiber Laser Engraving Machine so could be a interesting way to finish enclosure.

Edit: Pro Co Rat, looks interesting
https://www.electrosmash.com/proco-rat