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).
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.
If you prefer not to DIY, choose an Assembled product.It comes fully assembled, ready to use.