Electronic – Low-noise audio-frequency BJT?


I found myself looking for a low-noise PNP transistor the other day.

I couldn't find any parametric searches that listed noise performance. Even from the transistor manufacturers. You can search by beta, \$V_{ceo}\$, and \$I_{c}MAX\$. All these searches seem to return a table of every general-purpose part in the manufacturer's portfolio. Not helpful.

This circuit needs to have low-noise at audio frequencies. RF transistors seems to be better characterized for noise, but they aren't necessarily low-noise at audio frequencies.

The best I have found was a forum thread at DIYaudio, but the recommendations tended to be old-school, even obsolete parts. I'm looking for a mass produced transistor in SOT-23 or smaller.

So recommendations are welcome, but I'd really like to see a selection tool or parametric search that includes this information.

Best Answer

I found BC859/BC860 with a search on the NXP web site. They seem similar to the BC108 which used to be the low-noise device most people used to use.