Tymphany, a Cupertino start-up that provides audio transducers and acoustical engineering services, has received a $13 million investment from publicly traded American Capital Strategies.

The funding, reported in the San Jose business journal, came in the form of a convertible preferred equity from ACS, which has offices in Palo Alto.

Tymphany said the investment is being used to provide working capital for the expansion of its China operations and to support further product development and penetration of new markets.