Author Topic: NPN Boost: Problem with the Transistor?  (Read 2829 times)


NPN Boost: Problem with the Transistor?
« on: November 11, 2012, 02:00:17 PM »
Hey guys!

Sooo... Newbie here and having a problem hooking up a transistor. I wired the schematic and no sound so I got rid of everything and starting slowly using the amp as a way to have a feedback. Hooking output to input directly of course I have a good feedback. I added the first capacitor and no problems here. Now, I hooked the transistor... it doesn't make any sound. i hook up the input (already with the 0.1uf) to the base and then i try to get the output on the emitter and no signal and same on the collector.


Other thing. Can I connect all the grounds in one wire? Or this will be problematic? I've got all the ground wires together.


Re: NPN Boost: Problem with the Transistor?
« Reply #1 on: December 21, 2012, 08:42:09 PM »
I use LTspice to run simulations of this. I have often found that sometimes the design wont work at all until I add a resistor between emitter and ground.

If you could provide a picture of your circuit how you have it hooked up, I might be able to figure it out.

based on what you have said, these are possible problems:
Pinout wrong.
Wrong transistor/bias, such as NPN with negative going to base.
Input or output jack wired wrong. I've done this, and you won't get audio signal, but you get a nice humming and ticking like a bomb.
Transistors are Current driven Voltage biased devices. They require the DC bias in volts, but then they require the proper currents to get out of cutoff and stay below saturation. You might have a burnt up transistor, or again, it might be something switched around improperly. There's not a whole lot left I can say without seeing it. I don't know that much.
If I can solve the problem for someone else, I've learned valuable skill and information that pays me back for helping someone else.