The SK25 is a discrete Op-Amp that is pin compatible with the 2520 and "99" DOA's.
The SK25 is a discrete Op-Amp that we developed as a replacement for the API* 2520.
The SK25 will give its best noise performances with high impedance sources like high ratio input transformers (1:4 and above).
Everything!
You bring the solder (use good quality solder, 1mm diameter max).
The SK25 kit is not a kit for beginners because of the high density of components. It is recommended to people with some soldering experience.
Assembled Product: If you prefer not to DIY, choose an Assembled product. It comes fully assembled, ready to use.