BJFE / BearFoot fx Guitar Effects Community

So, I got ahold of a couple of 2n1304 transistors. How do I test them with a DMM?

Sweet T wrote:So, I got ahold of a couple of 2n1304 transistors. How do I test them with a DMM?

Does your DMM have transistor testing contacts? Youll see little holes with PNP and NPN as options.

Nope, it doesn't. I didn't know if you could just use your normal leads/probes for this.

Sweet T wrote:Nope, it doesn't. I didn't know if you could just use your normal leads/probes for this.

Not to test them for hFE which is the normal test. You can just socket them on your PCB and see if they work that way.

The 2N1304's I have are all above 40hFE > 50hFE. I imagine there aren't many leakage
issues since the Ge NPN xistors were the top of their game at time of manufacture.

YMMV

Hi,

About the NPN Germanium transistors suggested for this project further explained in this thread
viewtopic.php?f=10&t=1101&st=0&sk=t&sd=a&start=10

When using germanium transistors in this circuit either just one or two, change R2 in this schematic to 2K0 Ohms for increased gain.
Use 47K Ohm with higher gain silicon transistors or if you'd like to have wider sread on the potentiometer dial of low distortion sounds.

In BJF Folk Fuzzes I'd use a BC550C low noise, high hfe for T1 for lower noise and higher gain and then T1 gives stability and gain while T2 that would use a 2N1304 or similar gives most of the carachter of the sound.

A simple transistor tester can be built, but with the transistor suggested and in this circuit, there will be no specific need- this is because firstly there are dc feedback systems that keep the circuit working with a very wide range of transistors and also maximum AC gain is not utilized, which makes it possible to use a wider variety of transistors without circuit havocing.

Higher gain fuzz using the same sets of parts:

For those that have more than two pcb's on hand: it is possible to cascade two pcb's using the same layout of three controls, while gain on first in line pcb may need to be preset fairly low and EQ can be preset too if wanted.

Have fun
BJ