This circuit uses two quad op-amps to form an eight LED audio level meter. The op-amp used in this particular circuit is the LM324. It is a popular IC and should be available from many parts stores.

Juergen Grau has once again returned to Kickstarter to launch his Nixie IN-28 Dot tubes VU-Meter, under the Make 100 banner allowing those interested to help create a small production one of 100 units ...