Venture capitalist Manu Kumar has raised a new, $40 million fund, just three years after launching his Palo Alto-based investment firm K9 Ventures in the spring of 2009.

The fund, K9’s second, follows a far smaller fund of $6.25 million that Kumar raised mostly from individuals and that he has since used to back 18 startups, four of which have been acquired and several others of which have gone on to raise Series A and B rounds.

Among Kumar’s exists thus far are CardMunch, acquired by LinkedIn for $2.4 million, BackType, acquired by Twitter for an undisclosed amount, IndexTank, acquired by LinkedIn for an undisclosed amount, and card.io, acquired earlier this week by PayPal for undisclosed terms.

Asked if K9′s first fund is now operating in the back, Kumar emailed me this morning that it’s “doing really well. I guess otherwise I wouldn’t have been able to raise Fund II!!. But I cannot share the numbers.”

Kumar writes in a blog post that with his newest fund — which he will operate single-handedly, with the back-office support of a CFO — “for the most part everything remains the same as with the first fund, with just one major change: the initial investment amount. With the new fund, K9 Ventures will be able to invest between $250K and $750K as an initial investment in the companies we back. This will allow us to potentially lead the seed round, while maintaining an active engagement with these companies (as with Fund I). K9 Ventures II will still be syndicating most investments with other seed and angel investors.”

He tells me separately that he expects to invest $1.25 million on average into each company, “with the flexibility of going as higher –$2 million to $3 million– if needed.”

In his post, Kumar says the fund’s LPs include the usual suspects — “university endowments, foundations, family offices and fund of funds and key individuals” — without naming names.

Kumar has also told me in the past, and reiterated in our exchange today, that unlike many investors, he doesn’t subscribe to the growth-first-revenue-later mentality that runs throughout Silicon Valley. While that approach has worked out nicely so far for the likes of Twitter, Facebook, and Foursquare, Kumar says that anything he backs has to have a direct revenue model.

His other criterion include that he’ll only work with “technical founders – a team that’s capable of building its own product,” the company has to be in the Bay Area, and he’ll only back a company with a “radically new technology or that’s participating in a market where money hasn’t been changing hands prior.”

Asked what radically new technologies have caught his eye this year, Kumar, one of the first investors in the camera company Lytro (which he has backed personally, as well as through K9′s first fund), says he’s not allowed to discuss much yet but that “as a teaser, there’s a lot more interesting stuff possible with cameras.”

Image: Photo courtesy of K9 Ventures.