Can I replace BC549C with BC550?

[AllyP]

I plan on building the revision 2 transistor Obsidian (Thanks to RDV for the scheme) But I could not find the 2N5089s...I found a replacement (BC549c) but the shop (Maplin...I hate them soooooooooo much) Only had 3 (I need 4:().

I saw in their catalogue that there was a BC550 but it only had 100mA rating(BC549C had 200)


DO you think this will be a problem?

Cheers

[Joep]

yes, you can use then, you need the BC550C

Everything is well within the specs if you use them for the Obsidian.

Bye,

Joep

[acromarty]

Most effect circuits are only putting small signal currents through the transistors, so replacing a 200mA device with a 100mA one should be ok.
Check the value of the resistor in series with the collector, this usually determines the maximum load current when the transistor is fully on (saturated). Current I = V/R with V = 9V for most battery powered pedals and R is the collector resistor. You can only get 100mA through the resistor if it is 100ohms or less.

[AllyP]

Thanks very much....Your all very informative